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MetalMan
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02.22.2006, 12:13 AM

Quote:
Originally Posted by Superemaxx89
I hate to be the bearer of bad news, but:

Two 5s packs, while though they will power your truck, if wired in series the cells longetivity is at stake. Though you will have an LVP, what if the voltage per cell within the pack varies? The whole pack becomes usless b/c of one cell. Now if the 5s packs were wired parallel, if one cells charge voltage goes down inproportionate to the others, the other cells will proportionatly charge the cell to nominal level. In a nutshell, to power your sytem you should buy one motor (probably like a 12-14xl...why do you want to run two motors anyway?), one esc, save money (by only buying one system) and then buy--i know this may sound crazy-- two 10s packs and wire them parallel.

This is the only way to make sure your lipo don't undercharge and ruin themselves. An LVP is solving only 25% of your undercharging problems.
If 1 of 2 5s packs in parallel had a cell that went south, then the other pack's voltage would be forced to drop also, perhaps into the unsafe region. The way I see it, the best thing to do is get packs that are built in a parallel fashion so that if any cells go down they will only take their "mates" (cells in parallel with them) down instead of a whole pack that's in parallel. So, instead of 2 10s packs in parallel, 2 5s2p packs in series would be a better option. This also makes charging easier because each group of cells in parallel (2p) will maintain voltage amongst themselves that can be monitored via a single set of taps (so 10 cells to tap total), whereas with 2 10s packs in parallel you have 20 cells to have taps on.

If one cell in a pack went bad (dropped its voltage), then the LVC may be hit, which would stop you from running with the bad cell, creating less potential damage to an already damaged cell.


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