athletic91
100 W
Simple question, assume both packs are brand new balanced packs with 20c discharge
Can i parallel a 5s 5000mah and 5s 3000mah to make 5s 8000mah?
Can i parallel a 5s 5000mah and 5s 3000mah to make 5s 8000mah?
Parallel diff capacity lipo packs
- Thread starter athletic91
- Start date
icerider
100 W
athletic91 said:
The short answer is yes. but...
If the cell resistance is different between the 3Ah and 5Ah cells (and therefore the packs), then during high-amp draw the low resistance pack will source current a little better. When the high-amp draw stops, the low-resistance pack will have a slightly lower voltage than the higher-resistance pack and the higher-resistance pack will share its charge until the voltages equalize. This will cause some inefficiency in getting the full capacity out of both packs. I don't think this is likely to be a big effect, but it depends on the difference in cell resistance for the 5Ah and 3Ah cells. Perhaps somebody who works a LOT with LIPO has made the measurements and can tell us how different the cell resistances between 3Ah cells and 5Ah cells are likely to be.
For an application like riding at a relatively constant speed on relatively flat ground, this is almost certainly not going to be a problem. Big bad hills or off road where the current draw goes really HIGH intermittently will make the effect bigger but it still depends on how different the cell resistances between 3Ah cells and 5Ah cells are. My guess is that given the 20C ratings the effect will not be a problem at all, but that is no more than a guess.
dogman dan
1 PW
True what you said above, if they are both essentially the same, then it won't be a problem.
But an 8 ah pack of 20c lipo won't do a lot for you.
If you are planning a very high drain, then 8 ah of 20c cheapo packs will never be enough. They will sag like grannies tits if you pull 40 amps on them. It will work, but not near as good at 15 ah of cheapo 20c, or 10 ah of better cells.
If you are just going to run something moderate, like a 1000w ebay kit with a 20-30 amps controller, then you will be fine with such a small pack. I run a 22 amps setup with no problems on just 5 ah of 20c turnigy. It does have a bit less capacity than it would if I carried 10 ah, but it's ok enough.
But an 8 ah pack of 20c lipo won't do a lot for you.
If you are planning a very high drain, then 8 ah of 20c cheapo packs will never be enough. They will sag like grannies tits if you pull 40 amps on them. It will work, but not near as good at 15 ah of cheapo 20c, or 10 ah of better cells.
If you are just going to run something moderate, like a 1000w ebay kit with a 20-30 amps controller, then you will be fine with such a small pack. I run a 22 amps setup with no problems on just 5 ah of 20c turnigy. It does have a bit less capacity than it would if I carried 10 ah, but it's ok enough.
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