ianmcnally2 wrote:The question is do you hook up the batteries in series first then paralleled, like you did, or do you hook them up parallel first?
I am new to this and have wondered about that question not sure what the Correct answer is , but I know what works for me.
RallySTX wrote:TC, I sent you a pm, and I don't think one string of two batteries will get you very far. Remember, don't overcharge, don't overdraw, and don't forget to grin. Brian L.
mattetjus wrote:hey TC,
It will work, BUT, as i understand it (anyone feel free to correct me):
in case that the battery cells are not equally strong, e.g. capacity differs slightly between the individual cells, they may go out of balance.
A rule of thumb it is to parallel lithium cells first, then put them in series;
as you have the packs in your figure, (i'll name your cells, from left to right, A1, A2; B1, B2; C1, C2, attached png-picture) , I'll call this
you have the two packs A1 and A2 in series (likewise, B1+B2 and C1+C2) and these will then be paralleled with the B's and C's;
When/if a cell in e.g. A1 goes bad, as in internal short circuit or something, or if it simply runs out of juice before the others; the B1+B2 and C1+C2 strings will have higher potential than A1+A2 and will discharge some of their capacity through A1+A2, meaning: all cells in B1, B2, C1 and C2 may go below their acceptable Low Voltage.
Now, if keeping the cells paralleled (for you, this could be, connecting the balancing cables of A1+B1+C1 together, and likewise A2+B2+C2), you will 'only' endanger 3 cells in the case of a single bad cell.
for example, Cell 1 in pack A1 goes bad:
in your figure, potentially all the cells in B1, B2, C1, C2 could go below their preferred Low Voltage Cut Off -- 4 of 6 packs may go completely dead + pack A1 lost 1 of its cells.
If paralleled first, you'd discharge the first cells in B1 and C1 through the bad cell in A1 -> you now have 3 of 6 packs which have one bad cell each. (a bit better than the risk of 4 completely dead packs)
. Of course that would also mean taking a screwdriver with me to open the big gray box on my bike and swap out the batts.just take one of those packs in series instead of all three and run your bike on that. bring the extra pack in your bag and switch them out,
TopCat wrote:Have I buggered up 2 of my lipos?
TopCat wrote:Ha ha Kim, I pressed the wrong button --- Submit instead of Preview once i'd done the post header
So whats the story ToPCaT whats up with the LiPO? Over charge them over discharge them make fire come from them? LoL
AussieJester wrote:If you have read all the info on lipo in the battery section and are still struggling to come to terms with basics, it worries me a little you buying lithium polymer, perhaps lifepo4 would be more suited in this case, a Lifp04 Ping pack would suit yur setup and be alot easier to manage. lithium polymer can be dangerous if you don't have at least some basic knowledge and understanding of their requirements.
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