question

So after not being able to recover the batteries and being on a one-month trip with few service options, my only choice was to try to open a battery and check the bms and cells even though this would surely invalidate any warranty, the batteries are less than a year old and have been used very lightly with few discharges normally to only 60% SOC. The batteries are glued together but a thin spatula with taps from a hammer along the length of the glue easily separates the top from the bottom. Once open the construction is as expected with LiFePO 4. My first thought was resetting the BMS, the BMS is connected to the cell busbars via a small plug held in place with some silicon adhesive. After removing the adhesive, removing the plug from the bms and reconnecting, there were a few flashes from LED lights on the BMS and the after checking with a voltmeter the battery was showing a steady 13V. The next step was to charge the battery and no problems whatsoever, the battery was accepting a charge normally. The battery seems to be fully recovered; I therefore performed the same procedure on the other two batteries. All six batteries are now working again normally although I have not tested any of the protection functions of the BMS on these batteries.

I find it quite concerning that a product that retails in Europe for approx. €1000 has no option at all to reset the electronics, and there is almost no documentation published except the datasheet. If indeed the simple reset I have performed recovers a dead battery, then this option should be available via a switch and there should be some kind of troubleshooting document available. This is not a €50 device purchased from a dubious source online.

That is an interesting story and telling story. You are of course right that high value items with a lot of electronics inside are not simply throw away items. The electronics can have design issues and to accept that a battery with a design life of let's say, 15 years and good for 6000 cycles is to be thrown in the bin because the electronics inside says "no" is hard to do. I have recently seen a battery with nice stainless screws securing the lid and full access to internal registers using RS485 so all parameters can be read and any issue can be identified. That is surely the way we are heading with these long life, very efficient lithium batteries.