Hi,
This is my goodbye to NiFe post.
I bought mine in 2016, in early 2019 I started seeing some failures (voltage < 0.6, some -0.02) when cells were discharging, and some cells had gunk in the bottom of the case. By early 2020 I was seeing a lot of gunk in the bottom of most cells.
The seller sent me some KOH to make up new electolyte, but after a lot of flushing, and replenishing of 6 cells, I ended up with 2 cells that I could still use, and another 2 that were not so good, but better than nothing. Ended up with a 2 litre container full of gunk.
Efficiency has dropped from near 80% to > 50%, partly due to only using 37 cells, instead of 40, and the higher minimum cell voltage that entails. Also need to charge at a higher voltage to get current into the cells. Using lots of water at the moment!
The seller has agreed to take the cells back, I've already received 50% of my purchase cost, with the other 50% when I return the 40 cells.
Hoping to have them crated up early next week. Luckily, I must have had a premonition, I kept the original crates, which have been used as a table for 4 years.
Seller is arranging collection of the crates, but apparently there's some Dangerous Goods paperwork to be completed first.
I did have 2 1/2 very good years of use. All I needed to do, was the occasional water top up.
The NiFe is dead, long live the LFP!
dRdoS7