FrozenStash
New Member
Hi everyone,
First time poster here, but I have been lurking for a little over a year. I am having an issue with one of my 48V LiFePo4 packs; 1 cell going much lower than the other 15.
I have 2 identical 48V100Ah packs at my off grid cabin, purchased from SolarPowerStore Canada. I have had the packs installed for around 9 months now and have not had issues up until 2 weeks ago, when I went out to the cabin and the packs were out on low-volt cutoff. 1 cell in pack #2 was down to around 900mV while the other 15 cells were sitting at around 3200mV. Pack #1 was the same with all roughly sitting within 20mV of each other right around 3200mV/cell.
I pulled pack #2 out so that I could still run my lights + heater off of pack 1 + the generator to charge it when needed - every other day if I leave the heat on.
After pulling pack #1 apart, I realized that the cells are not user serviceable as I had anticipated. The cells and jumpers are all soldered together, and not studs with nuts as I had hoped. I have attached a picture of the pack opened up so you can get an idea of what I mean. I have on order a 60V 5A DC power supply as I was hoping to pull the cell and top it up, and then top balance all the cells in the pack before putting it back into operation with pack #2. When testing the cells with my DMM a few days later, cell #7 was reading 1.9V, so it rebounded...
My question is this. As I am not easily able to remove cell #7, would I be damaging or somehow otherwise hurting the entire pack if I were to hook up the DC power supply to the cell while it is attached to the other cells? As in, try to charge the 1 cell while it is still hooked up in series with the others. I have thought of ways to remove the cell if I must, but it would kind of be a PITA to do, unless there is a way that is easier that someone could recommend.
I was hoping to top up the single cell to around the same voltage as the other cells, and then putting it back onto the charge controller to top the entire pack up and then try to top balance it using the charge controller. I know this is not the correct way, but being the pack is technically not user serviceable, i dont see many other options.
I live in the Arctic, so currently we get about 4 hours of daylight at the moment - saying it isn't overcast, which it has been every day - so solar cannot charge them, hence the generator for the winter months. It is not financially reasonable to send the battery back for warranty as it would cost me around $1500CAD for shipping and logistics as I live in a fly-in only community.
Any and all help is appreciated. Thanks,
FS.
First time poster here, but I have been lurking for a little over a year. I am having an issue with one of my 48V LiFePo4 packs; 1 cell going much lower than the other 15.
I have 2 identical 48V100Ah packs at my off grid cabin, purchased from SolarPowerStore Canada. I have had the packs installed for around 9 months now and have not had issues up until 2 weeks ago, when I went out to the cabin and the packs were out on low-volt cutoff. 1 cell in pack #2 was down to around 900mV while the other 15 cells were sitting at around 3200mV. Pack #1 was the same with all roughly sitting within 20mV of each other right around 3200mV/cell.
I pulled pack #2 out so that I could still run my lights + heater off of pack 1 + the generator to charge it when needed - every other day if I leave the heat on.
After pulling pack #1 apart, I realized that the cells are not user serviceable as I had anticipated. The cells and jumpers are all soldered together, and not studs with nuts as I had hoped. I have attached a picture of the pack opened up so you can get an idea of what I mean. I have on order a 60V 5A DC power supply as I was hoping to pull the cell and top it up, and then top balance all the cells in the pack before putting it back into operation with pack #2. When testing the cells with my DMM a few days later, cell #7 was reading 1.9V, so it rebounded...
My question is this. As I am not easily able to remove cell #7, would I be damaging or somehow otherwise hurting the entire pack if I were to hook up the DC power supply to the cell while it is attached to the other cells? As in, try to charge the 1 cell while it is still hooked up in series with the others. I have thought of ways to remove the cell if I must, but it would kind of be a PITA to do, unless there is a way that is easier that someone could recommend.
I was hoping to top up the single cell to around the same voltage as the other cells, and then putting it back onto the charge controller to top the entire pack up and then try to top balance it using the charge controller. I know this is not the correct way, but being the pack is technically not user serviceable, i dont see many other options.
I live in the Arctic, so currently we get about 4 hours of daylight at the moment - saying it isn't overcast, which it has been every day - so solar cannot charge them, hence the generator for the winter months. It is not financially reasonable to send the battery back for warranty as it would cost me around $1500CAD for shipping and logistics as I live in a fly-in only community.
Any and all help is appreciated. Thanks,
FS.