unmatched cells
 

I feel stupid asking this, but if youre running packs in series what are the negative consequences of using say 12 matched cells and 4 cells of a different make?

Will they blow up or something, I'm just really interested in seeing what 16 cells will do in my jet villain IV and I dont feel like driving a total of 140 miles to get more matched cells, when I have many packs laying around.

If it'll just most likely kill the inferior cells, then I dont care, it's worth it for the experiment but I dont want to ruin my boat, my 12 good cells, or the motor. To give some info my 12 cells are 2400 mah and the unmatched packs range from 1200 to 1400 mah, of different brands.

p.s. my setup can handle 16 cells, limited only by the motor.

RE: unmatched cells
 

If you keep the disharged amount less than the smallest capacity cell then you have no problem. If you happen to discharge any more then it will definately reverse the voltage of the low capacity cells and hurt them. That is quite a large difference. I'd advise somehow trying to at least match the nominal capacity.

RE: unmatched cells
 

i would try the packs you have laying if you have enough to make the 16cell pack withe them so you dont rewin your good 12cells and just make sure that when you run the 16 that are diff rape them in something so if the do heat up they dont melt your hull or anything else:) JUST MY 2CENTS:)

RE: unmatched cells
 

now heres a more specific question? Lets say I wire in 4 cells, Do I put it before the 12 cells or after them in the series.? Maybe it doesn't matter.

RE: unmatched cells
 

Where you wire them is of no consequence, most important is to discharge / charge the 16 cells (as one pack!) a number of times, so the get as matched as possible, capacity-wise.

Still like the others said, don't run this odd combo too hard, certainly stop before the speed drops.

Regards, Jan.

RE: unmatched cells
 

alright well that sounds right, I had been thinking that since the 12 cells will be double the capacity of the 4 cells, I want to stop before or when 1200 ma have been used, otherwise the 4 cells will turn effectively into a wire instead of a battery, which I would guess couldnt be good. Correct me if I'm wrong, its been a while since my electronics classes in college.

thanks for the advice, I'm going to make the 4cells pack removable from the series, but with gold connectors, I'll be trying this out in a few hours, and today I think I'm going to make a video, running the big lake today. :)

RE: unmatched cells
 

Im' not sure if this is what you are already doing but I will suggest it to make sure.
Make or buy your batteries in a flat side by side configuration and it will be easier to make chages in the future. To add batteries just solder them on. and visa versa. I really don't like stick packs my self. I wish they didn't put the "battery holder" in the SV in the first place. My flat packs don't fit that well in the SV battery holders. I found that in my Aquajet Exteme from offshore, the hook and loop system worked just fine.

RE: unmatched cells
 

thanks for the advice, this winter I was already planning on doing that. Right now I'm just experimenting, I honestly just want to see what the 700sc is capable of, since as of now the motor doesnt even get warm. I'm going to get those gp3800's I hear so much about, and make the side by side packs.

bah, I'm still waiting for my old pack to finish charging so I can go do this. :(

RE: unmatched cells
 

I recommend powerpole connectors and to treat the packs seperately when chargeing. If they are all full at the same time they'll pull down to the lwest capacity cells (4) and then slow down, You should stop imediately.

Another way to do it is to have them all dead, and charge the higher ones only to the same capacity as the lower ones hold. The bigger cells are not full, but they will ALL be more equal "at the empty mark"

RE: unmatched cells
 

well it worked, I charged them all seperate, because I have no choice, my charger only goes up to 8 cell. I ran it till the power dropped off then stopped. Needless to say, speed was dramatically increased, no idea what, but it was fast. The motor didnt get past warm, the 12 matched cells seemed normal and the 4 small cells may be fried, I couldnt even touch them for about 10 minutes. No melting or anything, but I think I'm not running 16 again till I make custom packs. Thanks for all the advice though, even if I couldnt follow all the directions. Todays video will be up shortly from the run in my main thread

RE: unmatched cells
 

Sounds like a successful Test. If you get all 16 quality cells now you'll notice another decent improvement in power because of the quality and ability to maintain a higher voltage under a load than your other batts.