You really are not running ANY kind of protection with your battery pack?
The only "meltdown" was when you allowed the voltage to drop below the safety zone and it burned out about 25% of your batteries. (as you were riding?)
Did the fire occur in such a way that you could smell it or feel the heat as you road?
Do you use any protection in your charging or are you simply dividing things up into small units and then praying each one is okay?
It's safer and better than the rather goofy way that I soldered my 12s8p pack.
What protection would I use? Each subpack is charged individually by a single cell 1.5 amp charger -- which is a very low charge rate. Each and every single cell is balanced with every charge this way. The chargers themselves only have one voltage setting: 4.2V. It seems virtually impossible to overcharge the batteries because as 4.2V is approached, the current trickles down to zilch.
1. You charge your pack(s) with a SINGLE CELL charger? How could this be, since many 4.2v constitute more volts, there for the charger will detect LOTS more volts, and not even begin to charge.
2. Your pack(s) don't have a charge-discharge electronic board, so how do you know when the batt pack has reched it's discharge limits?
If that thing bursts into flames, look what gets roasted.
Got Nomex underwear?
I didn't see any PTC's. Was that a previous pack? Those work like a fuse, but suck at high currents.
They do make much more stylish duct tape. I use black.
I used to have a roll of camoflage duct tape, great for that "military grade" look.
Your total disregard for the conventions of "safety" is having an effect. Rather than me being worried about Lithium batteries the lack of fear you demonstrate tends to make me also want to "risk it" and build a pack without all the PCB's and crap that makes the things overly expensive and complicated.
Do me a favor and create a new "technical thread" and just walk through category, by category all the areas that you need to watch out for and also what is "overhyped" as a fear. (when you are done with your ride of course)
What about, a dum-charger? (Dum= no automatic cut off, no lights, just DC current).
One that would mimic a fully charged battery. One that would give constant 4.2v from the beginning, until you unplug it, like a fully charged battery that never runs out of juice.
Would it charge the other batteries, therefore the whole pack?
Because, if one battery has more juice than the others in a pack, it will give its juice to the others, right?
That bike needs a wash!! check your shock absorber on the rear ha ha, does it move?
I want to know how the batteries are charged,one by one ? no BMS contol it when the batteries charged
Questions : So when you pull the batterys off the charger, how many volts does a cell read when resting?
Also, what should the cut-off voltage be per cell from your experience?
You charge them up to like 4.15-4.20 volts. You take the charger off and it stays at that voltage?
A Sla for example charges to like 14.4 but then when you take the charger off, it sags to 13.04 resting.
I was just trying to figure out how to get the most voltage out of a 55 volt controller if a person builds his own pack.
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