ISO04B is not good at all. Tested. It’s too weak and get twisted. First E-TOXX chain drive was sold with ISO04B at the time. Then it used ISO05B and later ISO06B.
ASA25 is good if you take care of the chain. Not for 80100 motors obviously but for 6374 it’s OK. Advantage : you won’t snap your motor axle with that : chain breaks.
I think ISO05B is little stronger than ASA25.
yep i did exactly what etoxx did
04b-shit, alright for a single drive longboard tho
05b-works fine, imo good option for a lightweight/lower power jumper
06b-min for any powerful mtb
08b-i have managed to nuke it on my racing mower, but still overkill enough for boards.
This is what happens if you go too low with Lipo packs :
Two ZIPPY Compact 6200mAh 6s in series for a 12S mountainboard. They were bought at the same time. Always used together.
A funny detail is that pack B store-balanced faster than pack A.
I experienced that several times.
That’s why IMHO you shouldn’t go too much below 3.7 V/cell.
i race drones, weld with 2 lipos, unchanged since I got them, and used lipo for my board for over 2k miles, o i got my own experience 
I always bring the battery back to 3.8V for storage, charge at 2C or less in most cases, and don’t let the packs sit at <3.3 or at 4.2 for more than 24 hours, and i’ven’t had many issues especially on the larger packs
to each their own
@poastoast The problem is when you put lipo packs in series or in parallels. At the end of the ride the two packs won’t have the same voltages especially if you went low. That’s what happened in my reported case.
Your voltage cutoff recommendation for people with healthy, equal capacity packs, is too high.
You are using the lipos in series, and they have slightly different capacities. Your pack A is higher capacity than pack B, and thus it reaches a lower voltage faster when you are discharging them in series.
If someone has packs with more closely matched mAh (capacity), then there is no issue draining them down to 3.3v or 3.0v.
Based on what you showed above, I wouldn’t be concerned about running those packs down to 3.3v average cell voltage. That would make sure the lower capacity pack B doesn’t go below 3.0v/cell. (39.6v total pack voltage)
There is no harm in stopping a ride at 3.8v/cell, but you are leaving range on the table.
my welding is done in parallel and my board is put in both series and parallel
generally advice to any sane people is don’t try to understand the @poastoast approach to batteries. It might make your head explode 
These 2 lipo packs were sold as identical and were always used at the same time in series. In truth, these 2 packs do not ultimately have the same capacity. So if it’s a question of getting the most out of lipos to reduce the weight of the batteries and therefore keep the machine as light as possible, it is better to use lipo alarms than to trust the average cell voltage indicated by Metr. It was bad to have to walk home carrying all the mess.
a must have for lipos.
lipos imo are lottery based. some handle abuse amazingly, others need a good lovin
This has more to do with the quality of your specific lipo batteries, and less to do with the general best practice. It makes sense in your situation to never go below 3.7v/cell, but that doesn’t mean that it should be the general guideline for everyone else. Sounds like pack B is starting to go bad.
I don’t think pack B is going bad. It equilibrated faster than pack A in storage. The resistance of the 2 packs are identical (12-14 mOhms). My understanding of the phenomenon is that below 3.6-3.7 V/cell the chemistry is unstable and a bit unpredictable. Moreover, as reported above, the purchase of Lipo is a lottery, regardless of the brand.
The lost weight of 6355 compared to my previously 6380 was very nice for offroading imo, plenty of punch too so i wouldnt doubt the reachers pack even more. The only thing i do not like as much are the brakes, those could be a bit better, however i run them foc which is notorious for slow movement braking, i would recommend smart reverse.
Is that a parallel connector? Cells are 7s packs right?
edit: ahh saw ur post. Looks like each one is a 2 x 3s connector. So you end up with 21s6p?
I just finished using 6355s including a set of four on a 4WD mountainboard. They were impressive for their size. The only thing is they scream in the higher RPMs and I got noticeable vibrations coming into the deck from them. I’ve gone back to larger motors.
It was a bit like riding with little two-stroke engines.
mmmmmhm
