I have a 20A 10A Epever MPPT Solar Charge Controller 12V/24V Battery Regulator Max PV 60V with an oversized solar panel. A friend is docking his boat with 2 12v batteries 100ah for this week. I wanted to rig up a charging system. His trolling motor is 24v but I thought I'd connect 4 clips to the batteries and planned on using an old somewhat thick ac outdoor extension cable from the controller. I'm actually using the thicker wire (10AWG) on my own boat's 12v battery and wondered how much of a difference that would make? I'm quite a distance from the hardware store but wonder if I just go ahead and get the thicker wire if it would make a significant difference. By the way, I have some of that thick green wire used for grounding an outdoor ac system. Not sure if that would be acceptable? Thanks for advice on this.
Wire gauge importance for solar regulator to trolling motor batteries
- Thread starter billfloat
- Start date
sunshine_eggo
Happy Breffast!
10A is pretty measly and well within 10awg limits. The biggest issue is connection quality followed by length. Clipping to the battery is among the worst ways to make a connection.
Clips will induce a notable voltage drop. During charging, the controller will "see" a higher voltage than the battery's actual voltage. This typically results in premature charge termination and failure to fully charge. A long wire run will have a similar effect.
If you have no other choice, I would loosen the terminal and sandwich the wire under the terminal. Inconvenient, but you'll get a much better connection.
Interesting. I hadn't thought about the clips being inefficient. I could hook the wires straight to the battery. I'll use the thicker wire. My electronic knowledge is quite basic. The 12v batteries are connected in series for the 24v motor. If I connect the charging + and - wires parallel would I have any problems connecting both 12v's this way? Thanks.
MisterSandals
Participation Medalist
You need to charge your batteries as a 24V bank. Otherwise you will get out of balance.
I you were thinking of series connections with parallel connections, that will produce a short and will create an impressive spark display (no not try).
sunshine_eggo
Happy Breffast!
To charge @ 12V, you will need to disconnect the batteries from each other and either charge them individually as 12V or wire them in parallel and charge them together.
If you attempt to connect a single 12V charger to the 2X 12V in the 24V battery, you will have a bad day.
WYtreasure
It's not happy hour, I'm just like this.
My vision was of the spark igniting gasoline fumes.
Yikes. I thought about that but wasn't sure. No experience with 24v in my setup. It's right by the house so maybe the simplest solution for just this temporary time is for me to just switch them manually, charging one 12v at a time? I'm going to have a look and see how accessible they are. It might just take a little time to disconnect the series connector. Thanks.
sunshine_eggo
Happy Breffast!
Preferred and simple would be to parallel them.
Here's the reason you can't go to both 12V in a 24V battery with a 12V charger:
You short the + and - together on the 24V battery. BZZZZZT!
If you simply disconnect the interconnecting cable between the two batteries, you're good.
Similar threads
