Recent content by justaperson76

Charging at 0.25C definitely won't cause any harm. Honestly I'm really in no rush to charge, it's fine if it charges the whole day really as I'll pre-charge the day before use, while I am home. Yeah hopefully I don't get any bad cells :) I've let them sit for many days and they've all held...

It would be 2C if my pack is 1P but it's 4P remember, so 0.5C. I won't be going any higher than that.

Thanks for the info. My charge/discharge will be conservative. I will only be operating between 3.1v to 4.0v for now until I get a rough idea of how long this thing will last. As for charge rates, I will only be charging slow (well, recommended rates at least, 0.5c). The charger I have (x8...

Thanks. This all makes sense. You are right, I should have used the full capacity charge rather than nominal. I'll be charging to around 4v or 4.1v max to prolong life, so total of 28.7v. Seeing I am only charging at 0.5c, then I think that means I will only need a PSU that does half the above...

I have been looking more in to this and have came to the following conclusion: 4p = 12000mha (3000 * 4 Samsung 30q batteries are 3000mha) charge rate = 1.5A, or 0.5c, = 6A (1.5 x 4p) 7S = ~26v, so 26V * 6A = 156W Therefore as long as my PSU can output 156W then I'll be fine. Eg, I...

Actually I just realised that the max charge current for that charger is 30A, so I'm pretty sure my calculations are incorrect.

Hello, I have a question about charging current. Hopefully this is my last question regarding batteries(!) So I have two 7s4p batteries that I will be charging separately, and I'm trying to determine what current I should charge at. I have a hobby charger (icharger x8). All my cells are Samsung...

Ok cool, that's good (about the venting). I've weighed up the pros and cons of this setup and have not taken it lightly. The whole pack will be pretty tight. There will be hardly any vibration at all. It's for a (kids) quad bike which (he) will be going pretty slow. Once the magnets are all...

Hello, I am building (almost built) a battery pack (14s4p). I am using magnets to hold the nickel strips. To cut a long story short, how much of that "vent" can be covered up? I've seen battery packs have tape wrapped all around the battery and/or pack which looks like it has very little air...

Thanks again. That gives me confidence. It's not the end of the world if it blows but will see how it goes anyway.

Thanks amberwolf. I took some more pictures and had a look. It's still a bit hard to see. The black caps along near the fets it says 50v. There's a little red one near the battery that is 100v. There's also a 25v and 16v one but they're obviously irrelevant. I'll probably just try it and see...

Ok I have opened up the controller and checked the FETs and capacitors. I will post pics. Is this something that could handle 14p?

Yeah I can imagine. It would take some time to get over that completely, if ever. Hopefully there are no more unwanted events. Ok I understand. I have been looking in to this recently so I understand how they work now, how charging goes through phases, how it's constant current and voltage...

Thanks for the reply. I went to bed after my last reply. I will reply properly later (don't have time at the moment), but I am 99% there, just my terminology on some things are lacking. Thanks. I always appreciate the time it takes for people to help out.

Definitely new cells. I think I must have my definition of top balancing incorrect. I just thought that before they're all connected together, you want to get them all close to the same voltage as possible then parallel charge them to get them all roughly the same (balanced - I thought this is...