That seems overly cautious and potentially a lot of work that may not be necessary
I’d just get the lowest current charger you can get your hands on and charge the entire pack directly, not through the bms.
The easiest way to do this would be through your discharge lead from the battery, assuming you aren’t discharging through the bms. This way you can still have the bms connected and you can monitor the cells as they charge
Always coming in hot. I don’t think he’s using 30t cells…
Coming in hot? I’m responding to insults again.
You’re making statements, they are being quoted. You’re engaging. Rage bait. and you’re defending an opinion based off of an unrelated spec sheet. This argument is so old you could have gotten confirmation from the manufacturer by now of your theory, have you? It would put the whole thing to rest and cost only an email. It would be nice to actually have primary information here or it’s just gonna keep coming up and continue to be as relevant as preferred colors for series connections.
The statement I made and quoted above was literally from years ago now
Theory? Trickle charging cells under 3v is no theory and described in numerous data sheets. I just posted one again. But I didn’t even bring it up, again.
If someone is going to bring up something from ages ago, which they obviously still don’t understand, and try to insult me at the same time, again,… yes I will respond.
Here’s what I posted recently. Hardly questionable or antagonistic
Whoa…whoa…whoa…that is a moderate-nickel-content, all graphite, NMC chemistry cell from years ago. You can’t possibly apply its specs to all cells.
Especially now that there are extremely high nickel cathode NMC cells (with lower thermal stability), artificial graphite and graphite+silicon anodes cells, along with different “standard” li-ion chemistries like NCA (Molicels and others).
There can be other cells with low voltage “recovery” recommendations but the 30T’s datasheet ≠ all datasheets. And also realize that recovering a cell does not mean it was done without damage to the cell.
If anyone is considering telling someone that they can “recover” an over-discharged cell please be sure to check the datasheet for that specific cell before doing so.
I dont know the cell he’s talking about and it wasn’t mentioned as far as I feel like looking. It’s not up to me to tell everyone to figure out their specific details. I’m just here to state there are li-ion cells you can trickle charge n bring back from as low as 1v.
Just for posterity:
**It is your unsupported opinion that they can safely be restored to normal use after dropping below the stated minimum discharge voltage despite the spec sheets for most modern power cells specifically saying that they will be damaged and no longer perform at or maintain their nominal characteristics if they fall below their stated minimum discharge voltage. This voltage is specified as a different set point with different wording for different cell models and chemistries and the method of trickle charging and what that means is not universal between manufacturers or models from the same manufacturer.
Further the manufacturers have not been consulted or asked in any way what their acceptable conditions are for this method beyond the published data sheets and the included testing procedures which often state that the cell should not be allowed to be discharged lower than the minimum discharge voltage.
Also the BMS’s we typically use don’t have a balance current suited for constantly rebalancing a cell that is consistently slightly behind the others due to being revived at one point.
50s. Power cell. No safety concerns mentioned when trickle charging from 1v
From the way the warranty is worded it seems they’re still under warranty if doing this as well.
they’re not going to warranty the battery when it’s dangerous or they’d be sued instantly.
I see no way to interpret their data sheet as stating it’s dangerous. It’s not my opinion.
Another power cell from a different brand (Sony vtc6a). Says can charge from 1v. No protocol for doing that charge even given and assume follow the temp restrictions
They could have stated the cell is damaged/dangerous if below 2.5v and can’t be used, but they don’t
They do state no more than 5 in parallel and 10 in series permitted. People do it often without a thought.
Panasonic, Sanyo, Sony, and Samsung all post data sheets for their current cells that state cells can still be charged from 1v (with very low current).
I’m not here to play safety patrol. If u want to do something with any cell look it up in the data sheet and see if safe first. I shouldn’t have to say this but…
Can we change the title of this thread to The Skateboard battery builders club.
It could help weed out technically correct info that would be foolish to follow in the context of an esk8 battery (9/10 times li-ion and ≥10S ) for 99.9% of people using this thread as a guide?
It def is a conservative approach but I’d already started with the 2 lowest groups. The BMS is still stuck in protection mode even though all of the cells are well above 3.0v. Anyone know how to reset the bms? I’m gonna just unplug the balance harness and leave it for a couple of hrs or so unless someone has a better idea. The interwebs have shed no light on how to unlock it through the app.
Also, @hummieee you’re still beating the ever-loving shit out of this obviously dead horse? Da fuq, dude. That’s lame af.
What exact model is the JBD ?? Not trying to insult your knowledge, but have you check the discharging bottom and charging? Try using another app.
Also change to another configuration and set it back again.
I have had luck completely disconnecting the bms and letting it rest a minute or two then restoring the connection. Haven’t had a jbd need this but other bms it has worked when locked down.
You will have to clarify, friend as I don’t understand. It’s this model:
This is a screenshot that I took last night. You’ll note the “protection locking” indicated. On a newer version of the Xiaoxiang app the “soft lock” was indicated as being engaged.
Did you desolder the CH- wires and everything? I’m thinking just pulling the wiring harness should be enough, no?
Its likely because you have a significant delta at 0.111. Try getting that delta below 0.1 and you might have better luck
If u go up and read u can see I didn’t bring it up. After It was brought up I once again showed that yes u can recharge from 1v.
But u know that and gave the guy who started the bull again a thumb up. Maybe no one will try to insult me while bringing it up again and it will lay.
Lame ass himself will hopefully realize u can do it and won’t call on me again.
The irony is there and u can still charge from 1v with power cells or whatever else and many data sheets say so. Are they and myself wrong?
