Ok thanks!
Were you using it for charging only?
An 8S pack on a 10S BMS would trigger the low voltage cutoff when the cells are at ~3.6v lesving quite a bit of range on the table
I really donāt understand the issue with adding a switch to a BMS. I mean FETs are already there, just turn them off.
edit
the bms seems not to limit the current below 36v, hereās a video where I start at 31 v
could it be smart so it bases the cutoff on how many balance leads are actually connected or do you think I lost the discharge protection from the bms?
Ok, so I did a little test today. I went out with a full charge through the bms and brick charger. Rode till my battery meter was showing about 38.5v When home and opened up the enclosure and checked each individual cell. the voltages where 3.855 3.859 3.864 high 3.857 3.859 3.855 3.859 3.855 3.846 low 3.849 Max spread between highest and lowest cells .018v Does that sound like the BMS is balancing the pack during discharge or do you think Lipo cells can discharge that evenly without assistance?
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Those swings arenāt too bad. 0.018v high to low Iād consider really good. I think lithium cells can discharge that evenly if theyāre good cells (which I assume yours are) and theyāre not very used, but that is such a low swing that I would agree that your BMS is doing some balancing during discharge as well.
I imagine as the internal resistance of a cell increases (as they age, which I doubt theyād do perfectly together) they donāt discharge as well so they become unbalanced easier. Most of that is just gut talking, so feel free to correct me.
These are quality packs with very low internal resistance. I tested them when first received and if my memory serves, they where all below 2 miliohms. I would like to do another test taking the pack from full charge down to at least 36v or 34v and then see how the spread looks. Iāll do that soon and post it here.
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Much appreciated @Namasaki. We all thank you 
(<- thatās supposed to be a bowā¦not sure what it actually looks like)
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So, to get back on topic. Since I started using my BMS for charge only I havenāt had any cut outs due VESC rebooting itself on fully charged battery under braking.
It has been working so good that Iām buying a US$ 10 BMS for charging only for my next build, itāll save me space and keep me out of future problems.
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I have never had a problem with my Vescs cutting out while braking down steep hills on a full battery while discharging through my BMS.
Thatās because you use a Bestech BMS, the Battery Supports one cutās off current when itās goes beyond 42v
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Oh, I didnāt know that. Another strike against battery supports
This might be a little off topic but Iām wondering how high the voltage on the battery can go temporarily before it presents a hazardous situation.
That depends completely on the internal resistance.
With a high internal resistance stock voltage could already fry the battery, while at very low resistance it could take a lot more current. Every battery will be different in that case.
Yes but I was talking voltage not current. And specifically voltage over 4.2 per cell during regen braking
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I have read through this thread an have actually learned a bit. I do still have a question though. If I bypass the bms that has a built in e-switch, do I then need to install an inline switch or will the BMS e-switch still operate.
The BMS eswitch will not work when bypassing
That sucks. I have a brand new 80A Bestech BMS that does not power on.
I foolishly bought an 8s 60A discharge BMS for my pack that I recently made, (foolish because I decided just to bypass for discharge and 8s high A output BMSā are like rocking horse shit), and after many cycles my pack is in great shape!
Next time Iāll just get one that can fast charge and not care about the A discharge rate.
So I can just say the hell with it and order a BMS just for charging?