Electronic – Solar panels sharing two controllers on two separate batteries

solar energy

Installed a system for a client but it's not working well.two panels each 175watts have 2 bringing in 350watts to a controller of 10amps to charge two different batteries of 100Ahr each total of 200Ahr so if I get another charge controller of 15amps and connect to this system but each controller charging a battery of 100Ahr but using one powerful solar panels bringing in 350watts will the system work well?

Best Answer

If you use 2 pannels, with 2 controllers and 2 batteries, than this is a normal system. It will work correctly, if you want to put the controllers, pannels or batteries connected toghether, than thats a problem.

With the first system, the only problem you will have is the different charging and discharging of the battery, your panels are the same wattage, but the batteries are different A/h.

If you want to use both batteries in a series connection, you will need to be sure that the controller supports charging the battery while its connected in series with another battery. 1 of the batteries will die fast as it will not be able to provide the current needed like the other one and it will be damaged by the high current flow. 

Connecting different A/h batteries in series is strictly forbidden!

If you want you can use the batteries in parallel, this should work, but 1 of the batteries will get discharged more and you will not be able to use the full capacity of the bigger one. Also when the first one gets discharged, you will be overloading it(draining too much current), which can damage it.

Connecting different A/h batteries in parallel is not recommended.

The correct way is to use 2 pannels, 2 controllers, 2 batteries and 2 circuits. If you are using an iverter you will need 2 inverters, if not you can use 2 circuits for each battery directly.

What I would recommend is using 2 pannels in series, 1 controller and 1 battery. If you can use 2 controllers in series, you can charge the battery from each panel. It should be possible to use 2 panels, 2 controllers and 1 battery without a problem if your controllers are with normal quality. You must have 1 battery only! The specification is as follows:

Panel wattage: 340.28 W 
Controller current: 19.44 A 
Battery A/h: 151.67 Ah

With this specification, you can use a 350W consumator(device) for 4 hours per day. Of couse the sun light has to be enough.

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