My voltage can drop as much as 5 V If I’m really getting on it, I’m using cheap Chinese batteries though. How much do you guys typically see?
Follow up question, when you reach cruising speed, does your voltage go back up?
Yes this voltage drop and rise is completely normal
5v though? Seems high on my 10a4p 8ah battery I can hit the soft cutoff after 4 miles due to the sag.
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Any idea what cells?
I get 6V of sag that brings me to 32V on a 10s 6Ah pack
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They say Shenzhen
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What cells?
I know my cells are garbage, I just wanted to get going for cheap. They will work until I’m in a position to build a better pack
4p 30Qs don’t sag more than 2V for me.
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Fake 30q
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10s2p 30q, I sag about 4/5v when pulling 24a from the pack ( 12a batt max for each vesc)
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2v sag would be great. I could triple my useable voltage range if I wasn’t hitting the cutoff making me go slow.
Unavoidable with cheap chinese cells. Even quality cells with a low discharge rate will sag off. 30q are tried and tested to run safely at 20amps so in a 4p thats 80amps of usable draw. Normal riding will keep you well under that so sag becomes unnoticeable.
I’m going to try and monitor my app tomorrow while riding and watch what’s happening. I feel like my voltage doesn’t rebound very well either when I get to cruising speed. I’ll watch the sag and also the amp draw. I’m set at 30a battery max on single drive.
Its a simple thing if you don’t over think it. The more current the pack is capable of the less stress you put it under if you operate below the maximum. I find 60amps on an 80 amp battery to be the sweet spot for me in control and discharge sag. If I run my 12s4p at 80 it does noticeably give less power over the cycle. It is snatchier at speed too. (battery max is torque at speed, motor max is low down torque)
My brothers trampa lipo set up is capable of nearly 500 amps and there is no sag at all right through the cycle. 10% battery left and the thing still tries to rip the soles of your shoes off.
Set your stuff up with some head room and things not only behave better they don’t blow up.
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well stay tuned boys and girls… im currently building a 12s5p with the liitokala 21700s for science to see what happens and how they respond… probably be a week or so before I finish it and get to riding it but worst case scenario ill throw it in my delivery ebike if they suck for my skate #backupplan
but current discharge/charge testing with my imax netted about 3500ma so id say capacity wise theyre on par if i discharged more… =)
however on topic my 12s4p 30q kicks ass on 6" tires all the way down to about 15-20% before I start to feel it slow down
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I’ve also been looking into 21700 batteries. I need to search more but I was thinking 10s3p Samsung 40t vs 10s4p 30q
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I’m doing 2 packs right now with the 30T. Same 3000mah but true 35amp discharge. @Accrobrandon that percentage is exactly where I feel mine start to really drop. Still the best performing cell I have used so far so I’m hoping the 30T will be even better. As recommended by @eBoosted. Alan tends to make me spend money. All those ride videos had me buying shit every time he put one on the tube.
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5v of sag is ok if you are pushing each the cell to 20a of discharge, that’s what 30Qs have of sag. If you are did gargling only 10a or 5a each cell, then it’s pretty bad
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