Maple Dave
New Member
- Joined
- Nov 24, 2019
- Messages
- 12
About 4 yrs ago, I watched Will Prowse assemble LiFePo4 cells and I jumped in to the tune of about $2500 to get 16 cells. I have a grid connected/battery backup solaqr system at my sugarhouse (maple syrup).
I assembled the 16 cells in series, used a BMS that claimed to shut off at just above freezing and put a 65 watt heating pad under my 48V 100AH battery bank. I had 1" blue foam under and all around the battery bank to help contain the heat. The connecting cables were copper 4/0 high grade from a big name US based solar company, made to my specified lengths.
I am located in central New York State, about 25 miles east of Syracuse. The sugarhouse is not heated. I have only one small heated closet in the sugarhouse with 2 forms of heat, a propane 8000 BTU wall furnace which has a standing pilot, and for back-up a 1200/1500 watt electric heater. The furnace thermostat is set for 40F and the electric is set at 36F.
We had a major snowstorm which covered the solar panels, and I couldn't get into the sugarhouse and solar panels for 2 days. When I got there I first cleaned off the solar panels, then went into the sugarhouse. The grid power and the propane furnace both worked as they should, but the BMS failed, and apparently tried to charge the battery bank when it was frozen, the 65 watt heating pad had drawn the 48V 16 cell bank down to 17V. I tried to fix them, I unbolted the bank (it was 8x2 cells, each row of 8 had a long bolt to clamp them together. I then took 8 cells home and tried to charge them using an adjustable charger. I set it for 1.5V and 2A for a day. My hope was that it would accept the charge and I was going to gradually increase the voltage until I got each cell up above 3V, then I planned to bolt them back together and connect the solar to them to fully charge the whole bank When the low voltage didn't work, I stepped the voltage up about 1 volt at a time until I was at 14V, the highest my adjustable charger was capable of. The first cell never took a charge, I tried a few, each 1 at a time with no luck. $2500 worth of cells was now worth nothing, total scrap.
If you go with LiFePo4 batteries, be sure you don't make the mistakes I made. I've been out of the 1480 watt portion of my solar array ever since (actually 4 years next January) Next week, I'll finally get 4 12V AGM batteries so I can again send my excess electric thru my net metered system. I'm using AGM because they require no maintenance and can be charged at any temperature I'll ever get. I no longer use it for emergency back up heat, but my Xantrex 6048 inverter can't be run without the battery bank attached and charged. Then it is set to send power to the grid once the battery bank reaches 56V. That is then credited to my residence bill, I live 3 miles away.
By the way, we also have a 1770 watt fully off grid solar set up at the residence with 4@6v each Rolls Batteries each 853AH for an independent 24V system. It's not connected to the grid power at our house.
I assembled the 16 cells in series, used a BMS that claimed to shut off at just above freezing and put a 65 watt heating pad under my 48V 100AH battery bank. I had 1" blue foam under and all around the battery bank to help contain the heat. The connecting cables were copper 4/0 high grade from a big name US based solar company, made to my specified lengths.
I am located in central New York State, about 25 miles east of Syracuse. The sugarhouse is not heated. I have only one small heated closet in the sugarhouse with 2 forms of heat, a propane 8000 BTU wall furnace which has a standing pilot, and for back-up a 1200/1500 watt electric heater. The furnace thermostat is set for 40F and the electric is set at 36F.
We had a major snowstorm which covered the solar panels, and I couldn't get into the sugarhouse and solar panels for 2 days. When I got there I first cleaned off the solar panels, then went into the sugarhouse. The grid power and the propane furnace both worked as they should, but the BMS failed, and apparently tried to charge the battery bank when it was frozen, the 65 watt heating pad had drawn the 48V 16 cell bank down to 17V. I tried to fix them, I unbolted the bank (it was 8x2 cells, each row of 8 had a long bolt to clamp them together. I then took 8 cells home and tried to charge them using an adjustable charger. I set it for 1.5V and 2A for a day. My hope was that it would accept the charge and I was going to gradually increase the voltage until I got each cell up above 3V, then I planned to bolt them back together and connect the solar to them to fully charge the whole bank When the low voltage didn't work, I stepped the voltage up about 1 volt at a time until I was at 14V, the highest my adjustable charger was capable of. The first cell never took a charge, I tried a few, each 1 at a time with no luck. $2500 worth of cells was now worth nothing, total scrap.
If you go with LiFePo4 batteries, be sure you don't make the mistakes I made. I've been out of the 1480 watt portion of my solar array ever since (actually 4 years next January) Next week, I'll finally get 4 12V AGM batteries so I can again send my excess electric thru my net metered system. I'm using AGM because they require no maintenance and can be charged at any temperature I'll ever get. I no longer use it for emergency back up heat, but my Xantrex 6048 inverter can't be run without the battery bank attached and charged. Then it is set to send power to the grid once the battery bank reaches 56V. That is then credited to my residence bill, I live 3 miles away.
By the way, we also have a 1770 watt fully off grid solar set up at the residence with 4@6v each Rolls Batteries each 853AH for an independent 24V system. It's not connected to the grid power at our house.