Just curious if anyone has tried this with smaller p-groups, 4P or less. I can see it working with a monster 10P pack or something like that. 100A coming back in wouldn’t be a huge issue for some good cells for those short periods of time.
But has someone tried huge braking current feeding back into a smaller pack successfully? Limited by the ESC’s ratings, of course. I realize that for some cells this could quickly cause a lot of damage.
I can see a board becoming unrideable after a certain point (look ma, I can fly!) but I’m curious how far the community has gone.
I have a 10s2p lg hg6 pack with 40amp brakes, on a nice curve, batteries still charge to 95%. Had since ‘18. Love them cells. Sad I can no longer find them. @Battery_Mooch, do you know what happened? Why lg doesn’t seem to be available anymore?
LG has been verrrry actively trying to get their loose cells off the market (no loose cells are supposed to be available for any purpose). They sent “request” letters to several large sellers of loose cells, asking that they stop selling them. Considering the legal efforts LG could easily make if anyone said no they all decided to stop selling.
I’ve always set my brake current as high as it needed to be to have a safe brake, without consideration to what the cells might take, considering that I don’t do hard braking often and only in emergencies
The strongest I’ve used is -18 A in a 10S3P of NCR18650GA that are know to not like high charge current, pack done maybe 1500 km in one board, part of it in a ebike for a while and now back together in another board
Curious if anyone knows… what’s the difference to a battery? Discharging vs charging? A total noob might expect them to be more similar. 30Qs w/ 6C discharge but only .5-1.1C charge seems a bit odd. How much of that is because charging is almost always expected to be continuous… until the pack is fully charged? how much can we really push into the pack momentarily like during 2-5s braking? Is heat the real enemy here and we can push as much as we want until things start to heat up? ramble ramble ramble
Interesting. So in your mind, is there a work around? Like who would I start hounding to find me some loosy goosies? What was your experience with the hg6’s? I haven’t messed with molicells yet and admittedly never used 30qs either.
Heat can be an issue but charging too quickly literally stacks up the ions in the surface of the goop on the negative side of the battery. This forces lithium metal to plate out onto the surface, robbing the cell of capacity and increasing the possibility of an internal short-circuit eventually.
Truth. Only issue being my enclosure was designed to fit 18650’s, so I’m limited to that form factor. Well, at least the 650 part of it lol. Likely going the 30q route in a 12s7 or 8p config, unless you think there’s a better performer in that size…
Awesome having you on here btw @Battery_Mooch. Always have respected your work. Appreciate your seeming lack of bias when sharing your info. Very valuable.
Just my personal recommendations:
For up to 5A-7A…Sanyo NCR18650GA.
For up to 15A…Murata VTC6 or Samsung 30Q (perform essentially the same).
For up to 25A…Molicel P26A.
For up to 30A…Samsung 20S.
IMHO it’s because users of their loose cells, particularly vapers, keep blowing themselves up and suing LG (and everyone else in sight). This costs LG time and money but most importantly it affects their reputation if the public thinks their cells are defective. This they will not accept.
I’m hearing about accidents a lot less but that won’t lead to the big manufacturers stopping what they’re doing. Samsung has also been very actively trying to stop usage of their cells outside of battery packs and Murata has had warnings on their cells for years.
Only Molicel openly allows use of their cells outside of a fully protected battery pack. Though, if they get sued a few times that policy could change.
