Simple Solar Battery Charging Station

[TucsonJim]

I purchased four 230Ah LiFePO4 batteries for our new RV. All the batteries were shipped at about 50% SOC. So I wanted to top them off while waiting. But I didn't have a charger that could top off LiFePO4 batteries. But I did have a few solar components laying around that would work just fine.

I used a Go Power PWM charge controller paired to a Grape Solar 200 watt panel with appropriate fusing between the controller and battery. I was able to get about 8 amps of charging current out of this set up. The batteries are 230Ah at 50%, so I need to pump in about 115Ah into each battery. This calculates to about 14 hours of sunlight to top off one battery. I need about 1-1/2 days to complete one. But hey, it works.

[prahawalker]

I did a similar thing but I was lucky enough to have a spare MPPT charger which charged it quicker. Thanks for sharing this very simple idea to help all of us out.

Jeff House

[TucsonJim]

I did a similar thing but I was lucky enough to have a spare MPPT charger which charged it quicker. Thanks for sharing this very simple idea to help all of us out.

Jeff House

Yep, that little PWM is pretty inefficient. It would have been great to have an MPPT. But in a couple of months, I hope to have three charging methods (Dual solar MPPTs, 60 amps DC-to-DC, and Multiplus II Inverter charger. But if I deplete all 920 amp hours, I'll need every thing I can throw at it.



Jim

[tbwilliams]

Yep, that little PWM is pretty inefficient. It would have been great to have an MPPT. But in a couple of months, I hope to have three charging methods (Dual solar MPPTs, 60 amps DC-to-DC, and Multiplus II Inverter charger. But if I deplete all 920 amp hours, I'll need every thing I can throw at it.



Jim

If you carry a portable generator with you, you might want to buy a lithium charger for those times when boondocking that the sun just won’t cooperate. We faced that up at Mammoth Lakes when the remnants of Hurricane Hillary went up through Nevada. We had several days of overcast/rainy weather so I plugged my 40a charger into my Yamaha 2000w inverter and had the battery bank charged up in a few hours. First time I’ve needed to use the generator in several years. I purchased the LiTime charger along with my 230ah battery because it was on sale at the time. You can almost always find one on sale at Amazon because all of the battery companies label the same unit with their brand. For example right now with the two coupons that are offered you can get a 40a charger from TimeUSB for $130.99 while the same exact charger from LiTime is currently $219.99.

[COReflection]

If you carry a portable generator with you, you might want to buy a lithium charger for those times when boondocking that the sun just won’t cooperate. We faced that up at Mammoth Lakes when the remnants of Hurricane Hillary went up through Nevada. We had several days of overcast/rainy weather so I plugged my 40a charger into my Yamaha 2000w inverter and had the battery bank charged up in a few hours. First time I’ve needed to use the generator in several years. I purchased the LiTime charger along with my 230ah battery because it was on sale at the time. You can almost always find one on sale at Amazon because all of the battery companies label the same unit with their brand. For example right now with the two coupons that are offered you can get a 40a charger from TimeUSB for $130.99 while the same exact charger from LiTime is currently $219.99.

Great post and idea but I had one question.....I have something similar with my camper but have a Powermax 125 A converter/charger for my battery bank. If I am going to run my generator...I can just kick on the converter/charger and use that to quickly charge my battery bank. I'm not understanding the need for a separate Lithium battery charger over and above the converter/charger. I'm sure I'm missing something though......Please enlighten me. Thanks!

[tbwilliams]

Great post and idea but I had one question.....I have something similar with my camper but have a Powermax 125 A converter/charger for my battery bank. If I am going to run my generator...I can just kick on the converter/charger and use that to quickly charge my battery bank. I'm not understanding the need for a separate Lithium battery charger over and above the converter/charger. I'm sure I'm missing something though......Please enlighten me. Thanks!

I bought the charger because the trailer I had at the time did not have a lithium compatible converter. I was also able to use the charger to individually get each of my two batteries charged fully from their shipped state before hooking them up in parallel. If you already have a lithium compatible converter, the charger would be redundant I imagine.

[TucsonJim]

Great post and idea but I had one question.....I have something similar with my camper but have a Powermax 125 A converter/charger for my battery bank. If I am going to run my generator...I can just kick on the converter/charger and use that to quickly charge my battery bank. I'm not understanding the need for a separate Lithium battery charger over and above the converter/charger. I'm sure I'm missing something though......Please enlighten me. Thanks!

My battery manufacturer is pretty specific about having all the batteries fully charged before installation and connecting them into a parallel bank.

Jim

[COReflection]

My battery manufacturer is pretty specific about having all the batteries fully charged before installation and connecting them into a parallel bank.

Jim

Yes sir---I can believe that and follow the same guidance with the (3) Big Battery LIPO4 batteries that I have. I love many things about those batteries including the individual power switches on each one. If I have an imbalance on one or more of them....I could just power the charged one down till the others caught up. So far that has not happened. By using the bus bar for all loads and charging....the solar and the converter/charger has been charging them equally. Overall---very happy with the product and the battery capacity. Good luck with your project as well.