While 4.25 is technically in spec (Li-ions are supposed to be charged to 4.2+/-.5) it definitely isn't good for the life of the cell.
I think I'll just be using my 6P holder I made out of a WP6, should work well for anything from 1 to 6 cells as long as I set the correct charge current.
Charging without a battery monitoring system/balancer is known as bulk charging.
(Lipos on fire! | Endless Sphere DIY EV Forum)
(Lipos on fire! | Endless Sphere DIY EV Forum)
In the electric bicycle world a lot of people bulk charge their packs and only periodically balance charge them. Some never balance charge them and this ALWAYS eventually leads to excitement.
Neither is a good idea, but if you are using matched cells known to be in good condition, you can PROBABLY get by with the occasional emergency bulk charge, but you are taking a vey large calculated risk doing so. If you are going to do it, do it your concrete bomb shelter. And invite Lumatic to watch. He likes to watch. J)
It seems that with both of those it happened when the cells were unbalanced. Since these had been measured before they put in and determined to be of equal voltage does that mean it is safer?
Yes… but no telling how much safer.
Also some types of cells manage to keep their balance so well that they don’t usually use balance connections. The Sony Konion cells in Makita tool packs are an example.
But even Makita is using balancers as today.
Their old packs did not have any balance connections or BMS circuit inside (at least I think it was Makita).
I think their new packs have a BMS. It is powered by the bottom cell in the string. The parasitic drain causes that cell to discharge faster than the others. Many recycled packs have only that cell bad (people leave the pack idle for a long time and the parasitic drain kills the cell)
this
i am lazy and do the same
i really only use my hobby charger for my nimh packs of lots of cells to power my mag458 etc
also to quick charge aw imr at 4amps and refresh old cells.
otherwise ultrafire is easier
Yeah, true for the old packs. Thats why I said today, newer packs use a BMS. Those are marked with a star.
But you are right about the misdesign in powering the BMS. Not noticeable in professional use, but for hobbyists that can be an issue.
Well, scaru already decided on parallel charging, I’m just going to reinforce his decision. There’s just so much less problem to think about with parallel charging. Serial charging WITH balancing can be disputed to be better. But serial charging WITHOUT balancing vs parallel charging, no question, just go with parallel.
At worst where you put very unbalanced cells, they simply balance out very quickly, slightly shortening battery lifespan. That’s it.
