Endless Sphere

I have respect of these batteries I know they can catch fire or even explode. So I have one last question: The picture of the charger (ebay link in my last post) says that there is output + and - wires and battery + and - which one I should I use, to charge the cells? I understand that you can use ...

You're welcome. And remember, be super carefull with polarity. Don't wear any metal ring or anything that could cause a short circuit. And if possible keep an extinguisher at close proximity just in case.

Matador

Now I understand, thanks! I looked for a charger and found this: https://www.ebay.de/itm/5V-1A-Li-ion-18650-Lithium-Battery-Charger-Module-4-2V-Charging-Protection-Board-/272969439726 This should work right? Thank you so much! It will work. It will be slow... charging at 1.0A, but it will work. In ...

Disconnect the JST connector off the BMS and tap in the balance leads through that connector and charge through them at 4.20V. Do that for each row of cells. Sorta like this: https://www.youtube.com/watch?v=qf4W3F2Lqhc or like this https://www.youtube.com/watch?v=DP1-VBNJmsg or like this: https://ww...

Then it's going to be the battery. I suspect you "BMS" does not balance. It's probably just a PCB.
You need to manually balance each cell group back to 4.20V using a Hobby Charger.

Butif you have a charger that has a switch to charge at only 90% or so instead of 100% (luna advanced charger), then maybe the end charging voltage is more around 54.1V or so... If so then your charge profile will be more like so: ------------NOT CHARGED: ----------------------------------------> CH...

So thanks for all replies! I just opened the pack and measured the individual banks at the bms connector. They are all at 3.79V but the last 2 groups (assuming 13 and 14) are out of balance, the first is at 2.83V and the other at 3.53V. So I need to balance the pack right? I heard of charging an in...

If it's a 52V battery (14S). Then full charge at 4.20V per cell (14 x 4.20V) is exactly 58.8V. Some charger by Luna offer a swith to charge at a lesser voltage than full (for example charge at 90% instead of 100%) to prolong the lifespan of the battery. Is it possible you have such a charger and acc...

Most BMS are made cheap. Thus the electronic is very basic, hence why it does feed up only of one row of cell rather than feeding equally on all cells. Plus if it is a balancing BMS, and if you use your eBike regularly, the BMS will balance the cells and you wont even notice the unequall draw of cur...

I bought this pack from an eBay vendor in Australia (I'm in Perth western Australia myself). They're definitely the 18650 types. That much I know. To answer your original question a pack with cells in relatively good condition (whatever that means) with let's say no more than 50mv variance from the...

I agree with you. It seems more modern cells age better than the ones used in the scientific paper on calendar cell aging. I personally have harvested 218 Sony VTC4 18650 cells (and 68 Sony VT4 cells) from Makita drill battery packs. I tested each one of these cells individually for capacity. With t...

A diode would work. I sucessefully did this in the past. Sy some of my pics of the mod here:
viewtopic.php?f=14&t=98771#p1446395

Matador.

This post explains it quite well. How to rebalance the pack:
viewtopic.php?f=14&t=107665

Matador

Also. At equal power (watts), higher voltages mean less current (amps). Thus you can get away with much tinner gauge wires (save on weight!) And minimise voltage drop.
Matador

Anyway, since I stored this pack for over 3 years, it's clear that maybe it's degraded . I think I might have stored it fully charged for some of that time but later on, I made a point to drain down to half. But it might have been too late when I did it sometime last year. Does this check out? Is t...

Be very carefull to not short anything. Be very carefull to plug in the right holes in the JST connector (don't skip one hole by mistake). Be very carefull not to reverse polarity when tapping in the JST connector. Take your time, don't rush anything. Probe voltage first (don't charge anything befor...

How can I manually charge individual cells like that? What do I need? What's the procedure? Here is a video example I found on youtube (he does it with an unbalanced lipo pack... Same prcedure with an ebike battery. Just unplug BMS first by pulling the JST connector ( the heavy gauge battery main w...

Let us know how it goes !
Matador.

This is a pretty classic case of BMS quiescent current unequally discharging only certain cells in the pack and the resulting inbalance triggering LVC too early when discharging and triggering HVC to early when charging. I'd say if no cells went under 2.5V, you have a 95% chance of being able to eas...

So if for a 48V batt (13S) if t should charge to 54.6V, but yours now stops a 52.6V. That's 2.0V lower than normal. And the battery shuts of at 49V but i'm thinking it should normally shut off at around 39V (LVC 3.00V per cell). I'm thinking your battery might look something like this: When CHARGED ...

Also, and this should be #1: if you can't charge the pack occasionally, disconnect the BMS! If left connected it will slowly drain the pack to power itself. Very good point. The BMS is likely the culprit. I'm not saying the BMS is bad, but you have to realise that BMSs have a very small but very re...

I like my electric skateboards better. Less weight, much more protable. I have a WowGo 2S (10S2P - 4Ah) 42 inch longboard dual hub motors (500W) for fun that tops out at 38 km/h with 15-20 km range (17 lbs) and a modified "small fish plate" 27 inch e-skate cruiser 200W single hub (7S2P - 4Ah) toppin...

With a 52V 14S Li-ion battery hot off the charger 58.8V), my 30A BBSHD spins at 180 rpm at the bottom bracket crank (or 155 rpm at the nominal 50.4V). If you somewhat overvolt it (you'll need a different controller than the stock which only has max 63V capacitors) to 72V, it should spin around 220 r...

Ah that ride felt goood ! 22.0 km (36V 8.0Ah battery) --> From 41.7V to 37.3 V (resting voltage). LVC at 31.5V... Did peddle a bunch though (between PAS High, PAS med and a bit of PAS Low... Last 5 km on throttle only).

Matador

EDIT: Now July 30th 2020, gave it a full bulk charge, stopped at 88% charge... B1 - 3.90V (-) B1 - 3.87V (-) B2 - 3.99V B2 - 3.96V B3 - 4.22V B3 - 4.20V B4 - 4.20V ----[Dschrg]---> B4 - 4.17V -----[Manually balance each group]-----> B5 - 4.20V B5 - 4.17V B6 - 4.22V B6 - 4.20V B7 - 4.22V (+) Total: 2...