not at all, just take into account all these aspect and evaluate the risks of the two (or multiple) options.
The best is to join efforts and open leaf BMS programming (or only configuration) that would give a "reasonable" safe use of the legacy BMS on different cells.
Hi @mux IMHO any new battery pack should not rely completely on internal passive BMS to balance cells. Use cases for the battery are so many that a BMS that is good for normal commuting use does not work for a taxi use.
So the feature request is to:
1) move BMS outside the pack in a water proof...
IMHO nothing that some almost empty to 100% slow charges can't solve with a good balancing especially with that so high Hx that is telling that most of the cells (well not only cells, but they are the most influencer in conductance if all is ok) are good.
In any case I would monitor cell 43 to...
I do not have a great numerical statistic, but seems most of that I found are that with many fast charges (also limited to los soc). E.g. seems unbalancing grow and grow and bring some cells to work near to upper or under voltage limits more times that the others cells creating a cascading...
so, it does not seems lazy, but having higher capacity (a new module/cell?) and it is only a balancing problem IMHO. BTW I would see behaviour of the cell at really low SOC (10 or 5%) and under load.
a you share screenshot at low SOC? sometimes, in 62 leaf battery, there cells that simply has higher resistence => they discharge faster then the others especially under load.
So a good analisys would add cell voltage at low SOC in quite and under heavy load mode (large accelerations to allow...
exactly! and this is not safe at all just using the BMS as it is with different cells. It is only "rasonable" safe because are NMC and most of them ave the same voltage ranges, but it is not enough and it need a strict control of the battery, e.g. it is not for people not involved in monitoring...
not at all other than reprogramming memory of the bms with new parameters. Sadly there are only two EU companies able to do this (no idea is Muxsan is able too) and they maintain secret on this. You have to send the BMS and thrust they give you back a reprogrammed BMS with reasonable and safe...
I did the test slightly more than 24h after added A LOT of sika 221 (two tubes also because a lot of previous sealant was removed). The test was successful :) e.g. gave the same leak as before opening the pack.
Other person professionally building water proof boxes and using sikaflex product ...
as said in this thread, one further step after leak down test, is to fill the battery of nitrogen to dry out. Some rough calculation give me that:
1) a leaf battery case is not more than 0.45m3 (probably would be something like 0.2 or much more less because filled of battery modules)
2) a liter...
An important note about Leak Down test. I did the test before opening the battery and it leaks just under the repair limits (probably from HV connectors tapped with tape).
how much time did you wait after closed the battery, e.g. how much time wait for sealant curing before apply "Leak Down" test? For the amount of sealant asked in the manual (almos 10mm) and sealant sika 221 I used, I would wait at least 6 days for a complete cure. Bus in some case this is not...
or build it yourself for cheap like considering that 1 delta cm is 0.98 mbars e.g. 0.0098 bars (almost 1 mbar then)
keyworks: build water column manometer