Page 3 of 4

Re: 12V Lights

Posted: Fri Jul 03, 2015 3:49 pm
by Stef
Will certainly work...elegant or not :thumbup:

One could use a simple diode setup as opposed to the switches/relays and replace the Ctek with a DC-DC charger also fed from the PSU.

Re: 12V Lights

Posted: Sun Jul 05, 2015 6:35 pm
by pietpetoors
Chris I realised I can do exactly that. No need for the charger to run 24/7.
If I switch off the Benton in the morning the battery can last all the way to the evening before we go to sleep without a charger.
No need for the Benton to be on all the time.

I am going to put the charger on a timer to charge each day from 23h00 to 06h00
That should be more than enough since it hardly ever falls under 11.8 Volt.

Re: 12V Lights

Posted: Thu Jul 09, 2015 7:00 pm
by ChrisF
pietpetoors wrote:O ja Chris, I see somewhere you mentioned one must get the correct charger for the 7Ah battery, so I did.

We now sell the 0.8 Amp CTEK especially for the smaller batteries.

http://www.4x4direct.co.za/batteries-an ... p-1805.htm" onclick="window.open(this.href);return false;
Pieter jy sal maar weer moet bestel .... :siffler: :siffler:

kyk hoe mooi lyk die laaier :acute:
DSCN2382 (Small).JPG
die PERFEKTE laai stroom vir daai klein batterye !!
DSCN2387 (Small).JPG

en toe sukkel die scooter en ek maak toe maar jou rak leeg .... :tease:
DSCN2438 (Small).JPG
DSCN2437 (Small).JPG

Re: 12V Lights

Posted: Thu Jul 09, 2015 7:34 pm
by pietpetoors
Agnee Chris, ons kan nie voorbly nie.
Ons kan al amper vir jou 'n kantoor gee daar.

Re: 12V Lights

Posted: Thu Jul 09, 2015 8:23 pm
by ChrisF
hehehehe .....

Re: 12V Lights

Posted: Thu Jul 09, 2015 8:30 pm
by ChrisF
Pieter ek was Dinsdag by my syster en gekyk hoe hulle stelsel nou lyk.

14Ah battery - R 280
Ctek laaier om die battery te laai.
een van die klein R300 power supplies - met die kan die 12V ligte direk van eskom krag gebruik word.

Wanneer die krag afgaan skakel hulle die dubble-pool skakelaar oor na die battery en hulle het genoeg krag vir die 12V ligte vir n load shed.


Werk regtig lekker :)

Re: 12V Lights

Posted: Fri Jul 10, 2015 9:12 pm
by pietpetoors
mmmmmh, ek raak nou baie haastig om my sonpaneel opgesit.
Ek het nou agtergekom as net ek en Elmi hier is, skakel ek die Benton soms net een keer elke 2 dae aan om die battery te laai. Dus , wanneer ek 'n ou sonpaneeltjie bysit gaan ek vergeet van die battery.

Re: 12V Lights

Posted: Thu Jul 23, 2015 5:13 pm
by ChrisF
Time for feedback of a slightly different nature - $$$$


I did NOT do the 12V light installation to save electricity. The hassle factor of eskom got me to do the battery and inverter installation, with the 12V lights as a secondary thought.


I did however do a full 12V light installation - to the effect that all but one room in the house is perfectly lit with 12V lights.

We have not used eskom lights for the last couple of months :)

We also installed a gas hob.


The cumalative effect is that our winter power consumption is about 10 to 15% lower than 2014 :yahoo:


basic calculation at this early stage is that even after buying the gas we will be saving almost R 1 000 over the next 12 months ..... :subscribed:


The payback period is still too long to make it a financial decision, but I am still happy :cooldude:



EDIT - 20 August - figures updated

Re: 12V Lights

Posted: Fri Jul 24, 2015 7:39 am
by Mud Dog
Well this was the initial reason why I started my project as well. Initially I was using a number of 7ah batteries with my LED camping lights. I decided at one point that we could leave them on every night, but it was becoming a hassle connecting lights / charging batteries every day. Even though we were still using some 'eskom' lights I noticed a small cost saving each month and decided to go for something more substantial.

I now run ALL lights (including my outside lights - 12 of them) exclusively off solar. On the very odd occasion here and there, we may briefly make use of an 'eskom' light, but my saving is now in the region of 270 KW per month which is roughly R4500 saving per annum.

My payback period is therefore no more than 5 years, probably substantially less if one takes into account the eskom price hikes in that period. (A noteworthy point here is that my installation costs exclude labour since it was all DIY.) So yes, apart from beating load-shedding it makes financial sense as well.

I also have a sense of great satisfaction when the neighbourhood is plunged into darkness, and my home and yard still remains brilliantly lit! :D:

Re: 12V Lights

Posted: Fri Jul 24, 2015 9:04 am
by ChrisF
Andy YES installation costs has a significant impact on the project costs !!


Then when we talk payback period it is so difficult to compare installations, as each municipality has has multiple billing scales .....

My neighbour has a fixed R1,76 /kW.h for the first 600 units, then R2,14 /kW.h per unit thereafter - 2015/16 Cape Town rates. Thus if he saves 5 units a day it is 5x1,76x365 = R 3 212 per year.

We are on a different rate scale, with the first 350 units at a very low rate, but thereafter we pay R 2,88 PER UNIT !! So if we save the exact same 5 units per day our saving calc looks like this : 5x2,88x365 = R 5 256 per year.

Thus it will be worth our while to get our geyser off the grid as well - pv here we come ... :)



sadly, for us, Cape Town wants to get most home owners over to the scale my neighbour is on .... that will instantly push up our account by about R200 per month. :(

Re: 12V Lights

Posted: Sun Jul 26, 2015 3:51 pm
by ôita
Try the android app "electrical cost" I came accross... You enter the cost per unit kw/h for your area and the watts for the applience or light and the amount of hours per day and the total days and it will tell you the cost for that applience per month. If you buy the pro version for about R12 you can add more and name them all... Therefore you can work out your whole house if you want and see what costs what.. Have a look I find it helpfull and interresting :thumbup:

Re: 12V Lights

Posted: Thu Aug 06, 2015 7:31 pm
by ChrisF
bit off topic ... well sort off .....

fine and dandy having 12V lights ,,,, but here is the next step for surviving a load shed :twisted:
DSCN2453 (Small).JPG

oops, sorry, meant to post THIS -
DSCN2452 (Small).JPG
and a nice set of quality speakers -
DSCN2454 (Small).JPG


aag nee wat, nou mis ek nie eens meer eskom nie ......

Re: 12V Lights

Posted: Fri Aug 07, 2015 1:56 am
by Mud Dog
Hehehe .... not a bad idea! I have a number of old car radio units lying about .... could put one or two of them to good use! :D:

Re: 12V Lights

Posted: Fri Aug 07, 2015 6:49 am
by ChrisF
Andy power was off from 17:00 to 18:00. We sat at the fire listening to the radio until 8pm.


This little Sony unit actually has an USB and iPod input. It does not have CD player, thus the unit is SHORT, making for a nice compact installation.

Re: 12V Lights

Posted: Fri Aug 07, 2015 9:12 am
by Mud Dog
Our power went off at at 6pm, switched over to inverter and watched TV (two TV's, decoder, CD player, ADSL router and PC connected - the CD player was juiced but not "on"). Heard the gate intercom beep at 8pm when the power came on but was too lazy to go switch off inverter and revert to mains, one TV was switched off at 9pm and continued watching the other till after 11pm before I went back to mains with perhaps another 2 hours or more left in the batteries. The PC runs all day, and so does the TV in the bedroom, so no way that the system can be used as a permanent substitute for mains, but at some time, just out of curiosity, I think I should let it run until it kicks out, to see how long it will actually last. :think:

Re: 12V Lights

Posted: Fri Aug 07, 2015 10:48 am
by Haboob
Andy, When you visit next Friday, make sure you bring your camera so that you can take pictures of the fittings & lighting in my house or Tony's. We have used mainly a single 3W LED light to light up a room or the braai area, the bathroom has 3 X 3 LED strips. I only have four areas lit up in my house for load shedding. I could light up the whole place like an xmas tree but do not live just for load shedding...
I use a small 12v gate motor battery & charger to keep my battery topped up and the flex is 0.5mm. Cheap as chips and serves my purpose...

Re: 12V Lights

Posted: Wed Oct 07, 2015 2:15 pm
by ChrisF
Had brain fade this morning and stopped at 4x4Direct .... :twisted:


Now this may be a moment of brillance or I may be going down the drain with this one .....


48 LED roof light for a vehicle ..... bought a couple of these to use for general lighting in the garage .... :siffler:


let's see how this experiment plays out ....


wonder what these lights will do if left on for an hour or three .... :eh:

Re: 12V Lights

Posted: Wed Oct 07, 2015 3:16 pm
by pietpetoors
I replaced the LED Strips in my canopy with ONE of these:
Image

Re: 12V Lights

Posted: Wed Oct 07, 2015 3:21 pm
by ChrisF
Pieter hoe verskil dit van die "48 LED" vierkantige weergawe ?


sal vanaand begin speel en kyk hoeveel lig so eenheid in n groot garage maak ....

Re: 12V Lights

Posted: Wed Oct 07, 2015 4:28 pm
by pietpetoors
Maak dieselle lig, is net die afmetings wat verskil.

Re: 12V Lights

Posted: Sat Oct 10, 2015 4:31 am
by Mud Dog
Those little dome lights are really bright to look at, but as many of you will have noticed that LED lighting doesn't carry very far by comparison to incandescent lighting (I think it has to do with the different frequencies of the light that comes off them). I have one of those square dome lights and it works fairly well in smaller rooms, but in larger rooms for the same current draw I think it's better to have it spread over a few smaller LED units that are spaced apart. :think:

Re: 12V Lights

Posted: Sat Oct 10, 2015 4:53 am
by ChrisF
Andy using strips of LED probably would have given better spread of light, at a much lower cost.

With the very concentrated source it also throws harsh shadows.

Certainly NOT for all applications !!


That said, My garage is more than 3m high, thus the light has a fair gap to spread. The aim of this exercise is to not switch on about 250W worth of 220W globes each time I want to spend a few minutes in the garage. ..... want dis mos nooit net n paar minute nie, gaan net "gou" in huis toe en n uur later sien jy die ligte is nog aan in die garage ....


If I want to WORK in the garage I certainly will still use the 220V lights.


I mounted each square light on a section of aluminium angle iron. The alu was properly cleaned, then the light stuck on with its double side tape. I then used two small pop-rivets to make sure it stays in place. The alu bracket was then screwed to the roof trusses.
DSCN2737 (Small).JPG
My helper on the work bench ... :tongue:

No flash -
DSCN2736 (Small).JPG

Re: 12V Lights

Posted: Fri Aug 05, 2016 12:29 am
by Mud Dog
One thing that makes a huge difference is the colour shade of the wall paint - white is obviously by far the best. I notice that our kitchen which is mostly white and a little less than about ½ the size of our lounge, appears far brighter than the lounge which is a light pastel colour. The kitchen has about one sixth the amount of LED's (excluding the under counter units which I only use when necessary- on separate switchs and not on all the time).

I do however have a question ....... I have bought a pure sine wave UPS inverter, to replace the inverter that I use for the TV's, computer etc. when there's a power failure. I had to go and physically switch on the inverter outside and then change the plugs of the TV's etc. over to the dedicated outlets inside. With the UPS the changeover will be automatic and seamless.

The UPS unit however cannot run off a 12V DC input like the old one, it requires 24V DC. There's no problem to configure the batteries and the controller as a 24V system but the question is this ..... The PV panels are connected in parallel at the moment and deliver on average between 18V and 22V which to my mind is not enough to fully charge a 24V battery setup. Can I / should I connect the panels in series to step up the input voltage?

The alternative is to let the UPS charge the batteries and use the panels for something else ..... :think:

Re: 12V Lights

Posted: Fri Aug 05, 2016 6:18 am
by ChrisF
Andy basically DC systems comes in "voltage groups" :

- 12V - our typical LIGHT DUTY (excuse the pun) 4x4 type applications. For these we use 22Voc and 17Vcs solar panels, with matched regulators.

- 24V - To keep the current draw in check, systems over 150 to 200W often switch over to 24V. This is the start of battery banks (2x12V batterries in series) and different hardware ... Now you use "HV" solar panels, ie 44Voc and 36Vcs solar panels, with matched regulators. It IS possible to re-configure your existing solar panels to have banks of 2 in series, and these banks connected in parallel. Sadly you will need a new regulator

- 48V - Many, if not most, of the large pv systems are 48V. Few of them actually use standard 12V batteries in series to make up the 48V banks. Typically these are made of banks of 1,2V cells


Thus for our light systems - 12V is perfect.

For tv's, computers, etc. it is possible to use a 12V system. BUT due to the current draw it is better to use a 24V system. But this same 24V system is not strong enough for the other household equipment ....

Something else to consider - 24V systems make use of battery banks, with batteries in series. You really should NOT be powering any 12V items of these !! This will cause uneven power draw from the different batteries, and cause havoc with the charge cycles, resulting in drastically reduced battery life.



Andy why do want to go down this road ? Long term energy savings ? Or purely as emergency backup ?

As a backup system only - consider a set of connectors on your batteries, that would allow you to disconnect two of the batteries from the main parallel bank, then to quickly connect these in series to the inverter ....

Re: 12V Lights

Posted: Fri Aug 05, 2016 7:36 am
by pietpetoors
Chris do you get a type of resistor or 24v to 12v transformer?
You do not get many lights in 24 volt, so if you wanna run your fridge, etc on 24 volt you either cannot do the lights or you have to have 2 systems.

Re: 12V Lights

Posted: Fri Aug 05, 2016 8:44 am
by ChrisF
Pieter this is the conundrum with the 24V systems ...

Too light for the heavy stuff such as fridges, while it is also not compatible with the 12V lights. For the purpose of this discussion 24V systems are only usefull for tv's and computers. Which begs the question of primary power source vs back-up power. As a primary source you are now moving into the territory of a "grid connected" type system .... but if you still need backup ... it is one short step, and a deep pocket, from a simple single 12V battery for lights to THIS :
IMG_1305 (Small).JPG

Back to Andy's situation :
A resistor type approach would waste too much energy. I am sure there should be a device that does the reverse of a dc-2-dc charger, ie it gets 24V and delivers a constant 12V for the lights. Though technically it can not be a "transformer", as we are working with DC circuits.




Thinking WAY outside the box .... it should be possible to set up the 24V circuit, then connect a charger/regulator from the 24V system to a lonely 12V battery, which would then power all the 12V lights. A quality charger will only charge as the 12V battery requires power, and go to idle mode when it is fully charged. Do remember the 24V system will be charging upto 30V, so the charger/regulator from the 24V to 12V system must be able to handle such a high input voltage.

Re: 12V Lights

Posted: Fri Aug 05, 2016 9:26 am
by ChrisF
julle laat my vanoggend so bietjie dink :subscribed: :twisted:


Lyk my daar is TWEE opsies :
1) you can use a CONverter, to go from 24V to 12V :
http://www.rpc.com.au/catalog/redarc-ba ... -1030.html" onclick="window.open(this.href);return false;

But then your max power is limited by this unit ....

2) Seems HCdP can adjust their chargers for this very purpose. Basically what I thought of in the previous post, but you then specifiy this usage and HCdP changes some standard settings to ensure the unit can charge a 12V battery from the 24V setup (with its own 30V charging parameters). I am sure Pieter can arrange this with them and supply from 4x4Direct :thumbup:

Re: 12V Lights

Posted: Fri Aug 05, 2016 10:08 am
by Mud Dog
Perhaps I didn't explain the situation properly again. My 'system' is of a 'modular' nature consisting of 4 modules - each module consists of 2 x 80W panels, a MPPT controller and two 105 AH batteries. At this time all the modules are 12V (batteries connected in parallel and the controllers set to 12V (the controllers can be set to handle a 24V configuration).

Over the last month or so we have had three short power outages (first ones in quite a long time), and it's a hassle to go and physically switch over. In addition, my inverter gave me a problem but has since been rectified - it's also a modified sine wave and not ideal for TV's / computers. For this reason I wanted to get something more convenient (no manual change overs) and with pure sine wave.

If I connect it to 220V AC and hook up the batteries (24V series) then it can run 24 / 7 as a UPS on my dedicated circuit (which is completely independent of mains power). However, I was just thinking that I could keep the batteries charged with the solar panels instead of using mains power to do so - (as I said, there are 2 x 80W panels and controller already there for those two batteries).

So, my question again, can I connect the two panels in series to up the voltage? Will it work? Will it have enough amps to charge the batteries? Would it even be worth the effort, or would it make more sense to let the UPS keep the batteries charged? (and use the panels / controller elsewhere). :think:

Re: 12V Lights

Posted: Fri Aug 05, 2016 10:16 am
by Mud Dog
P.S. The other three remaining 12V 'modules' will carry on running LED lighting as before.

Re: 12V Lights

Posted: Fri Aug 05, 2016 4:59 pm
by Family_Dog
DC converters are common enough, we stock them for 24v vehicles requiring two-way radios. Most of them are series regulated however, in effect still acting as a resistor, albeit an electronic one. I don't know if there are switch-mode DC converters available, these might be more efficient but also more expensive.


-F_D

Re: 12V Lights

Posted: Fri Aug 05, 2016 7:50 pm
by ChrisF
Andy if I read your post correctly, then your answer is on page 4. Page 5 takes it a step further in case somebody needs both options in a single system.


PS - been a long day in the office, pretty sure the article is vrot with typos .... will proof read later. Please PM me if you notice something, or even if you want me to add a bit more info at some point .... Once sorted I will give the article to Pieter as I am sure it may be of benefit to others.
12 or 24 V.pdf
(377.79 KiB) Downloaded 161 times

Re: 12V Lights

Posted: Sat Aug 06, 2016 3:01 am
by Mud Dog
Thanks Chris, the last schematic on pg 4 is exactly what I had in mind. I have to wonder though .... the batteries have to be connected to the UPS inverter as the back up power source, and even if I have the panels & controller connected to the batteries the UPS will still supply a charging voltage as well. It may well interpret the panel voltage as the batteries being full and switch to a trickle charge.

I could cut the power during daylight hours to simulate a power outage and run off the panels and battery, but the panels alone won't be enough to keep the batteries full.

Re: 12V Lights

Posted: Sun Aug 07, 2016 9:01 am
by ChrisF
Andy for the purpose of this discussion there are three types of "inverters" :

1) the classic stand alone unit - connect it to a battery and get 220V from it
DSCN2234 - Copy (Small).JPG
These are the typical "manual switch" units. It IS possible to rig up contactor to only, and automatically, switch on this unit in the event of a power failure.

Charging the battery is done by a totally different set of hardware.

PS - actually had to switch this unit on this unit on Saturday morning. Was busy in the kitchen when Bellville had a power outage of just more than an hour. Inverter on, roll lead out, connect kitchen appliances, finish my food prepping. :thumbup: eskom se g@t, well more likely the local municipality distribution network ....

With the 12V lights staying ON, and the 12V radio staying ON, it took a moment to realise we are having a power failure. :mocking: :lmao:


2) UPS type units. The difference between these and the classic PC type UPS is in the size of the battery bank, ie typically 2x105Ah batteries to provide a 24V system.

These would include automatic switch over. It typically also include an automated charging circuit ... HIER kom die sports !! To use this at home it may prove problematic to include a pv charging circuit .... these units rely on a fully integrated control and sensing circuit. It is very possible that the charge sensing circuit of the pv regulator and the charge sensing circuit of the UPS unit may result in some conflict ....

These units are meant to plug into a 220V socket and to be used "as-is".


3) grid tied systems. Now we are moving into the realm of full scale pv systems for the house. These systems manage all of the following at the same time:
- eskom input
- pv input
- battery charging, and using power from the batteries

clearly this is a totally different ball game.


4) well there ARE some other options .... I know that MicroCare merged type 2 and type 3 .... You buy an "inverter", which is actually an industrial type UPS, capable of a series battery bank. It is connected as a sub-circuit to your db board (this is what differentiates it from a proper type 3 system). This unit CAN accomodate battery charging from eskom AND from the pv panels. It also includes the auto switch over that you want.

I do believe Victron has a similar unit (actually MicroCare are cheaper copies of the Victron units)



Andy in summary I believe a type 2 UPS/inverter system. Use it as is. Not worth risking damaging its circuitry by trying to connect pv to this.


PS - I wanted to buy the MicroCare unit, finally went a different route as their waiting list was just too long .... decent products, crappy admin ...

Re: 12V Lights

Posted: Mon Aug 08, 2016 2:11 am
by Mud Dog
2) UPS type units. The difference between these and the classic PC type UPS is in the size of the battery bank, ie typically 2x105Ah batteries to provide a 24V system.

These would include automatic switch over. It typically also include an automated charging circuit ... HIER kom die sports !! To use this at home it may prove problematic to include a pv charging circuit .... these units rely on a fully integrated control and sensing circuit. It is very possible that the charge sensing circuit of the pv regulator and the charge sensing circuit of the UPS unit may result in some conflict ....

These units are meant to plug into a 220V socket and to be used "as-is".
That is where I stand and what I was thinking.

I haven't even unpackaged the unit yet but will hopefully do so and fit it during the course of the day tomorrow using a 220V supply as intended. The sales guy I spoke to appeared to be very clued up on all types of alternative energy and even did some complex calculations with some fancy formulas on a scratch pad at a speed that dazzled me. I had explained my intentions and he made no mention that there could be a conflict. That is of course no guarantee that there won't be and with the panel output not being high enough, makes me lean towards the 220V connection. I can use the panels elsewhere later, like for boosting the intensity of the LED lighting in side the house.

Thanks for all the feedback, appreciated. :winkx:

Re: 12V Lights

Posted: Mon Aug 08, 2016 10:11 am
by ChrisF
When you do unpack check the user manual. MAYBE, just maybe, the unit has a pv input. Mens mag mos maar hoop ...

Re: 12V Lights

Posted: Mon Aug 08, 2016 3:39 pm
by Mud Dog
I thought that it might, but alas, it doesn't.

I changed that particular module to a 24V unit and connected it all. Works like a charm but the PV voltage is still too low because I didn't climb up on the roof and change the two panels from parallel to series. Might just leave then off altogether for now.

When I connected everything and plugged my intended loads into the dedicated circuit (installed at the time of the original installation of the whole system), the battery read 100% full. I switched off the mains supply to the UPS as a test .... the changeover was smooth and seamless - 2½hrs later I checked on it and the battery capacity had only dropped to 94%. Admittedly one of the TV's was in standby mode, but I'm satisfied that it will be more than adequate for most power outages as long as they don't last longer than 6 / 7 hours.

Re: RE: 12V Lights

Posted: Mon Aug 08, 2016 4:13 pm
by Hunter26
[quote="ChrisF"

A friend is thinking down a completely different line - use a manual change over switch, on the light circuit. Then feed your standard 220V light circuit via an inverter. Thus NO extra lights or wiring, just the inverter and the change over system ..... To not kill the battery this would require the most energy efficient light solutions throughout the house ......



Would love to hear YOUR approach to this. :)[/quote]

Well if you use energy saving globes eg 20w saying 17 X 20w= 260w. Then feeding it into the light circuit via a change over switch via an inverter IMHO will be fine. Just be careful of ceiling fan globes as the ceiling fan and globes come off the light circuit, thus you will trip your inverter if fan is switched on

Sent from my D2403 using Tapatalk

Re: 12V Lights

Posted: Mon Aug 08, 2016 7:05 pm
by Family_Dog
17 X 20w= 260w
:o:

Maybe even elentyseventyfour watts, as per our Prez. :mocking:

As per me, well... I'll settle for 340 watts... but that's just me! :wave:


-F_D

Re: 12V Lights

Posted: Mon Aug 08, 2016 7:15 pm
by Mud Dog
:laugh2: :laugh2:

Re: 12V Lights

Posted: Sun Oct 23, 2016 5:23 pm
by Mud Dog
Just to revive this thread again .....

Yesterday morning (about 11am) I unplugged the UPS from the mains and used the plug for something else - this was supposed to be a temporary ½ hr interruption of the 220V supply to the UPS, but I became distracted and forgot about it.

The bedroom TV was on all day, as was the PC, monitor and ADSL router, DSTV decoder, and the 2nd TV was on from about 6pm onwards (both TV's and monitor are LED flat screens).

At about 8.30pm everything goes off! Couldn't understand it for a brief moment until I realised that I've been running off battery power for the previous 9 hrs! Went outside to plug the UPS back in and I was up and running again - battery power kicked out at 11.5V.

I had unintentionally done a load duration test with a typical everyday load. 9½ Hours! Not bad at all! :D:

Re: 12V Lights

Posted: Sun Oct 23, 2016 6:31 pm
by RiyadhFortuner
awesome. How many batteries you running

Re: 12V Lights

Posted: Mon Oct 24, 2016 5:20 am
by Mud Dog
RiyadhFortuner wrote:awesome. How many batteries you running
Read back in this thread - I'm using 8 x 103 a/h batteries with 8 x 80W solar panels which are broken up into 4 x 12V modules of 2 panels and 2 batteries per module, each with it's own controller. Each module has it's own separate supply circuit. The one referred to in the post above was taken off the solar panels, changed to a 24V configuration with 220V UPS and charged via 220V mains. Our TV's, decoder, PC's and ADSL router run off that module permanently. :winkx:

Re: 12V Lights

Posted: Tue Oct 25, 2016 9:15 am
by RiyadhFortuner
Mud Dog wrote:
RiyadhFortuner wrote:awesome. How many batteries you running
Read back in this thread - I'm using 8 x 103 a/h batteries with 8 x 80W solar panels which are broken up into 4 x 12V modules of 2 panels and 2 batteries per module, each with it's own controller. Each module has it's own separate supply circuit. The one referred to in the post above was taken off the solar panels, changed to a 24V configuration with 220V UPS and charged via 220V mains. Our TV's, decoder, PC's and ADSL router run off that module permanently. :winkx:


Awesome Thanks.

I would like to get to a similar point sometime.

Re: 12V Lights

Posted: Tue Oct 25, 2016 11:18 am
by ChrisF
The nice thing is that you can do 1 panel and 1 battery at a time ....

The most expensive part of my installation was changing a lot of 220v lights to more efficient unit which could also house LED lights


The pv geyser was done much later ...



Then a gas hob


Now using less than 8 kw.h per day from eskom

Re: 12V Lights

Posted: Tue Oct 25, 2016 12:18 pm
by RiyadhFortuner
I am already using led globes in my light fittings, a solar geyser and gas stove. So basically its just the oven, tv and computer, and stuff like Playstation etc. I have already brought by bill down by half over the last year and a bit.

My mission next is to power the outside lights via a solar panel and battery.

Re: 12V Lights

Posted: Tue Oct 25, 2016 3:44 pm
by Mud Dog
I have a total of 12 outside lights that run all night - that's way too much for one panel and a battery. What I did was split the circuits into two of six lights each. Each circuit is being supplied by a module of two 80 W panels, a controller and two 103A/h batteries (12V parallel connection). The first 4 panels on my array are for these 2 modules and the first two get a bit of shade from a tree in the early morning - what I have found in winter is that the lights supplied by these first two panels do not last the whole night if it has been a bit overcast - they kick out at about 4 / 5 am when the battery protection on the controller reaches 11.5V. This is the only module that does this, the others all cope with the load.

That should give you an idea of what you will need to power your outside lights. Also bear in mind that I made up my own lights with LED strip and if you look back in the thread, you will see how I made them and the how much they draw. Commercial 12V LED lamps may draw a bit more.

Re: 12V Lights

Posted: Tue Oct 25, 2016 5:18 pm
by ChrisF
Should also add that since we did our projects you now get 120-degree (WIDE angle) 12V LED downlighters.

These are just so much better than the typical old narrow angle units !!!!!!


BUT, 12V units are not available in all outlets .... and sadly getting more expensive.

Re: 12V Lights

Posted: Wed Oct 26, 2016 10:33 am
by RiyadhFortuner
The led lights I want to use outside are 10w and I most likely will end up using about 4 to 6. There is a possibility of using more.

Re: 12V Lights

Posted: Wed Oct 26, 2016 11:27 am
by Mud Dog
W/V = A so on a 12V system they will draw about 0.83A each .... not that wonderful if you consider them running all night, lets just say 12hrs on average. That means that each one will require about 10A/h of battery charge per night. Then if you further consider that a battery shouldn't be drained too low, let's say leaving 60% of the charge, it means that one fully charged battery will only be able to support about 4 of such lamps.

You could start there and then beef the system up later (as and when you're able) to support more lamps.

Re: 12V Lights

Posted: Wed Oct 26, 2016 4:29 pm
by RiyadhFortuner
damn where is the like button?

Well that is my plan. all in time, just to busy with too many things at once. I have until easter weekend to finish small renovations at home. Then I can concentrate on solar power

Re: 12V Lights

Posted: Wed Oct 26, 2016 4:45 pm
by ChrisF
Andy's maths are good ... just bear in mind the Cape Town winter .....

Our sun hours are very short, with a lot of cloud cover ....

So you need to put those amps back in about 5 hours, during winter months. 4 lights x 1A/light x 12 hours = 48Amps. So you want to charge at almost 10A, and charging takes place at 13,8V average, thus 150W panel - FOR WINTER.


The reality is that for 97% of the time a 100W panel will do the job. So now you decide if you want to drain that battery a bit more in winter, do you want to top up with a Benton charger once a month in winter - which is good to condition the battery.


In summer my system is fully charged before 10:00 in the morning. Mid winter, with cloud cover it sometimes does not charge fully .... Still it WORKS for US, and our usage. I understand the limitations, and do use the Benton 3 or 4 times a year - sometimes just to cycle the battery, not because of a lack of sun.


Welcome to the wonderfull world of green energy ... :)

Re: 12V Lights

Posted: Tue Nov 01, 2016 10:13 am
by ronnie
Any idea of where to get a 12V to 4V DC to DC converter in Cape Town area?

I know it's off topic so bullet the post if needed; just also know its the people in the know commenting on this current discussion

Re: 12V Lights

Posted: Tue Nov 01, 2016 5:51 pm
by ChrisF
Would a standard USB charger not do the trick ? Think that is mostly 5V output.

How many amps do you need ?

Re: 12V Lights

Posted: Wed Nov 02, 2016 8:12 am
by ronnie
ChrisF wrote:Would a standard USB charger not do the trick ? Think that is mostly 5V output.

How many amps do you need ?
Hmmm I didn't check....I want to run one of those small braai rotisseries off a deep cycle battery instead of buying the batteries they come out with.

I will have to check how much watt the motor is so I can do the amp calc

Re: 12V Lights

Posted: Wed Nov 02, 2016 1:14 pm
by ChrisF
Might want to get a "variable voltage" power supply for that.

The volts will be directly proportional to the turning speed ....

Re: 12V Lights

Posted: Tue Mar 31, 2020 4:38 pm
by pietpetoors
Wow, cannot believe it is almost 5 years later.

My 12 volt light system in my house is still running fine.
Up to now I used a Victron 15 Amp charger to charge my battery during the day.

About a month ago I upgraded the battery to a LiFePo battery. This made a huge difference. Because it runs at 13.3 volts the lights are a bit brighter, but the biggest difference is how long the battery lasts. I now charge it once a week, sometimes once in 5 days if we use the lights a lot.

Will be fitting a solar panel soon......... something I wanted to do 5 years ago.

Re: 12V Lights

Posted: Wed Apr 01, 2020 12:58 am
by Mud Dog
When we originally started with load shedding I was also charging batteries but you're still reliant on mains power and the saving is minimal. Got tired of the schlep of daily charging very quickly which led to the solar kit I put together.

So now, as you say Pieter, it's almost 5 years down the line. What I have experienced over that time is:

• the system is still working as it should, 365 days a year
• The LED strips I used to make my own light "bulbs" are not as bright as they used to be and some have 'yellowed' quite a bit while some individual diodes have completely failed here and there
• I have had to replace one battery about 4 months ago and I suspect that I will have to replace a few more soon. Remember I built the system up in modular stages over a few months and the batteries were not all bought at the same time. Actually not bad going for medium cycle 103ah "leisure" batteries, of which there are a total of eight. Think they cost about 1.2k at the time and the one I replaced was with a spare I had on hand.
• The system paid for itself in about 3.5 years, sooner than I anticipated due to the steep rise in grid electricity we experienced in that time.
• many times we are completely unaware of load shedding and only notice it if we want to use a kettle / microwave ot open the fridge and the interior light doesn't come on. (We don't use the 220V lights in the house at all unless we need to see a bit better, like when reading.)

About a year ago I supplemented my outside lights with three 'stand alone' solar street lamps (not part of the system I built up). They have variable settings and I run them on a medium light intensity all night where they come on at full brightness for about a minute with motion detection. My yard is well lit.

Re: 12V Lights

Posted: Wed Apr 01, 2020 2:11 pm
by pietpetoors
Yes we sometimes also do not realise when it is load shedding. Only way to know is when computer's UPS starts to make a noise and the kettle all of the sudden do not want to work.

I also installed some solar wall lights on the side of the house where there is sun. Those are very nice, you can add lights to the house without having to run any cables or without having to pay an electrician do do it. Just screw it to the wall and you have an outside light.

I like your street light idea.

Re: 12V Lights

Posted: Wed Apr 01, 2020 4:03 pm
by Mud Dog
This is what I put up. Came with mounting brackets and remotes. Think they were rated IP68.
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solartodes1.jpg
solartodes1.jpg (15.28 KiB) Viewed 9747 times
One I put onto a pole next to the driveway closer to the gate and another at the carport end of the driveway (mounted to the fascia of the carport). Third one I mounted on the top of the gable end on the other side of the house.

Re: 12V Lights

Posted: Wed Apr 01, 2020 7:31 pm
by pietpetoors
Is the battery inside the unit?