BAD ROW OR OUT OF BALANCE - 24v 2.8kWh 7s48p 334 Cell module
THESE MODULES ARE EITHER OUT OF BALANCE OR HAVE 1 BAD ROW OF CELLS. THE VALUE HERE IS OVER 300 GOOD CELLS, THE ENCLOSURE, CELL HOLDERS, WIRING, HARDWARE, ETC. SINCE THE NICKLE IS SO THICK ON THESE CELLS IT IS HARD TO PULL OFF THE NICKEL WITHOUT LEAVING A HOLE IN THE CELLS. IF YOU ARE SALVAGING THE CELLS SIMPLY CUT AROUND THE NICKEL LEAVING THE SPOT WELDS IN TACT AND SPOTWELD NEW NICKEL ON TOP OF IT. YOU ALSO COULD HAVE SOME LUCK MAKING THESE INTO 12S MODULES OR SOMETHING SINCE THESE ARE TECHNICALLY 2X 7S MODULES IN PARALELL.
This module has 334 name brand 2200mah power cells inside in 7s48p format. There are 2x 7s24p 24v modules wired in parallel. Making this a 25.9v 108ah 2.798kWh module. You can easily add your own BMS, in fact the JST 8 pin connector is standard for most 7s BMS units.
Most of these units have Sony, Samsung, or Panasonic 2200mah cells. This is the ultimate battery for many different applications especially since it is in a waterproof enclosure. Torqeedo makes batteries for their outboard electric boat motors. The BMS on these batteries is turned off and can't be reused. You will have to add your own BMS. Instructions for adding your own BMS is on the 2nd photo. Simply move the 2 positive wires to the positive post busbar, plug in the JST connector to your BMS, connect the 2 negative wires to your B- connection on the BMS, then connect your C- wires from your BMS to the negative post busbar.
The only tool you will need to open the enclosure is a 6" long T25 Torx bit. You can find them on Ebay, Amazon, harbor freight, etc. On the bottom of the enclosure there are around 20 bolts to remove then flip the battery back and the top will pull right off. This is a super easy battery to work with.
These batteries were only used a few times so you can expect excellent capacity and a very long life for solar storage use. Most of these batteries just had a faulty BMS which we can't reuse anyway or had a bad cell that brought down a whole group of cells. This battery is also built to push 180a continuous. Personally I would add a 100a BMS and limit the battery to 80a discharge or 2000w.
These are light enough to ship Fedex ground and we will cover the extra $37 hazmat fee and UN/4g box since all batteries above 300wh are considered fully regulated and require a contract and extra paperwork/fees which we are certified for. This battery weighs a little over 50 lbs.
The 3rd photo shows what the module looks like removed from the case. These are easy to remove if you want to take them out.