Hilux 4x4 Forum

In my dual battery setup I have a 105 A/H Deep cycle battery in the loadbin. This gets charged by a 12A HcdP dc-dc charger from 4x4Direct. Recently when we went to the Bull Run I also added 200W of solar panels on the roof to assist in charging the battery to keep the fridge running. Initially I thought I would use the HcdP as a Solar Controller and do the switching manually as the 12A HcdP model I have is one of those that work with the switch.

But knowing myself, and knowing the amount of stop starting and the nature of our stay in Vosburg, I knew that somewhere along the line I was going to forget something and either I am going to cook the battery or the contents of the fridge.

So I took the 20A Phocos Solar Controller that I bought long ago when I got my first solar panels and I connected the solar panels to that. And then I connected the Phocos directly to the Deep Cycle as well. So now, whenever the sun is shining on the panels, the Phocos is delivering charge directly to the battery AND the HcdP is also delivering charge whenever the engine is running.

Here is my concern. Can the setup as it is there damage the battery?

Thys , 1st thought I think you'll have to just monitor the total current going into the battery, but having said that, if both controllers are chargers in their own rights as well then I would not do it. They would be totally "confused" as to what the real state of the battery is.

You need something with dual input & auto switching, hence my reason for getting the D250S (although I think it's hideously overpriced) but I believe there are cheaper options out there from reading the Courage mod thread on Community http://www.4x4community.co.za/forum/sho ... 997&page=8

I inderstand what you are saying Stef... Are the controllers not supposed to take care of any "over charging"?

I just want to add that it worked great, the fridge stayed cold for 6 days without a problem.. There was some driving involved though..

ThysdJ wrote:I inderstand what you are saying Stef... Are the controllers not supposed to take care of any "over charging"?

I just want to add that it worked great, the fridge stayed cold for 6 days without a problem.. There was some driving involved though..

Thys I would have to agree with Stef, when the engine is off then the solarpanels and regulator will work perfectly.

I do like the HCDP product, the only downfall is that it is not solid state or sealed, so it cannot get wet. And that the 12a cannot auto changeover, other than that it is a good product

Thys, I had a similar quandary. What I ended up doing was using the same 20A Phocos controller that you've used (also got it from 4x4Direct), and connected my solar panel to the battery through that. I left the heavy duty cables in place that run from the main battery to the one in the bin With a 50A fuse on either end of the + cable. I also left the Cole Hersee solenoid in place as well, (no controller between the two batteries), and connected the solenoid to a toggle switch in the cab (the toggle switch is one of those that has a LED indicator so you can see if it's on).

The reasons why I went this route was specifically for the problem you described above and a dual input / auto switching charger like Stef mentioned is rather pricey, and this way was 'cheap as chips'. With the setup as it is I have a built in jump-starter at the flick of a switch in case the main battery is low, as sometimes happens when I don't use the bakkie for a while. I can also use the solar panel and 2nd battery to charge the main battery if I need to. If I'm travelling and the fridge is running, I sometimes open the solenoid to assist the 2nd battery. If travelling at night with the fridge on, I open in anyway.

I have used this setup for almost a year now and have had zero problems.

Thys you know Sarel on the other forum - Blinkgat products.


He has been doing this on his own vehicle for almost 100 000 km - DC-DC from the alternator AND another solar regulator from the solar panels.



To this day I dont understand how these clever electronics dont get confused with the multiple inputs .... it just feels wrong on so many levels. Yet, Sarel has had ZERO issues with this system. AND bear in mind he has two totally independant battery systems in his wagon, appart from the engin battery ! He has deliberately done side by side testing of different batteries and charging systems over nearly 100 000km.


for new installations he use the Mark 4 Power Panel from HCdP.

One option would be to feed the solar input into the starting battery WITH a dc-dc charger feeding the secondary. As soon as the voltage on the starting battery starts to lift above the threshold level of the dc-dc charger, the secondary battery will charge. Here is the trick: the solar regulator will lift the starting battery voltage enough to allow this to happen.
The alternator is a variable current source. Its supplies as much as is needed by keeping the voltage stable. As soon as the solar input starts supplying current to the battery, the alternator will back off.

JohanW wrote:One option would be to feed the solar input into the starting battery WITH a dc-dc charger feeding the secondary. As soon as the voltage on the starting battery starts to lift above the threshold level of the dc-dc charger, the secondary battery will charge. Here is the trick: the solar regulator will lift the starting battery voltage enough to allow this to happen.
The alternator is a variable current source. Its supplies as much as is needed by keeping the voltage stable. As soon as the solar input starts supplying current to the battery, the alternator will back off.

I have thought of this solution as well, and it does make a lot of sense. But somehow I feel that while the alternator is deliverig current, why not use it anyway, AND use the solar as well? Or am I just greedy?

If Sarel had no issues with his setup similar to mine for 100K km's, Chris, then I think I am going to just keep it as it is now?

ThysdJ wrote:

JohanW wrote:One option would be to feed the solar input into the starting battery WITH a dc-dc charger feeding the secondary. As soon as the voltage on the starting battery starts to lift above the threshold level of the dc-dc charger, the secondary battery will charge. Here is the trick: the solar regulator will lift the starting battery voltage enough to allow this to happen.
The alternator is a variable current source. Its supplies as much as is needed by keeping the voltage stable. As soon as the solar input starts supplying current to the battery, the alternator will back off.

I have thought of this solution as well, and it does make a lot of sense. But somehow I feel that while the alternator is deliverig current, why not use it anyway,AND use the solar as well? Or am I just greedy?

If Sarel had no issues with his setup similar to mine for 100K km's, Chris, then I think I am going to just keep it as it is now?

The less your alternator has to work the less power it needs to draw from the engine the more fuel efficient you become.

Makes sense Johan but since the Hilux was chipped fuel consumption went out the window anyway ...

ThysdJ wrote:

JohanW wrote:One option would be to feed the solar input into the starting battery WITH a dc-dc charger feeding the secondary. As soon as the voltage on the starting battery starts to lift above the threshold level of the dc-dc charger, the secondary battery will charge. Here is the trick: the solar regulator will lift the starting battery voltage enough to allow this to happen.
The alternator is a variable current source. Its supplies as much as is needed by keeping the voltage stable. As soon as the solar input starts supplying current to the battery, the alternator will back off.

I have thought of this solution as well, and it does make a lot of sense. But somehow I feel that while the alternator is deliverig current, why not use it anyway, AND use the solar as well? Or am I just greedy?

If Sarel had no issues with his setup similar to mine for 100K km's, Chris, then I think I am going to just keep it as it is now?

THIS is exactly what the CTEK 250 does.

starting with a low battery level - solar deliver as much amps as the sun can give, then the alternator is used to provide the rest to give the total of 20A as claimed by Ctek (actually confirmed this with my multiple volt and amm meter setup)

ChrisF wrote:

ThysdJ wrote:

JohanW wrote:One option would be to feed the solar input into the starting battery WITH a dc-dc charger feeding the secondary. As soon as the voltage on the starting battery starts to lift above the threshold level of the dc-dc charger, the secondary battery will charge. Here is the trick: the solar regulator will lift the starting battery voltage enough to allow this to happen.
The alternator is a variable current source. Its supplies as much as is needed by keeping the voltage stable. As soon as the solar input starts supplying current to the battery, the alternator will back off.

I have thought of this solution as well, and it does make a lot of sense. But somehow I feel that while the alternator is deliverig current, why not use it anyway, AND use the solar as well? Or am I just greedy?

If Sarel had no issues with his setup similar to mine for 100K km's, Chris, then I think I am going to just keep it as it is now?

THIS is exactly what the CTEK 250 does.

starting with a low battery level - solar deliver as much amps as the sun can give, then the alternator is used to provide the rest to give the total of 20A as claimed by Ctek (actually confirmed this with my multiple volt and amm meter setup)

Does the ctek push current into the starting battery? If not, then its not the same as my explanation.