E-S Stealth Electric Bike Owners
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Oldboy
10 W
You wouldn't be in Queensland by any chance shap08
shap08
10 mW
- Joined
- Sep 16, 2019
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- 26
Nah down in TAS
Oldboy
10 W
Ok might be a bit to far away. Can you send me a private message mate
Couldn't find one in quick search quite like yours, but "INR18650S" comes up as a low-power-low-capacity cell:
with item titles like
"ZhuoNeng INR18650S-2500mAh Power type 18650 lithium-ion cell 3.6V 2.5ah 2500mah 3C discharge for e-bike/LEV/ESS"
"Battery 3.6v 2500mAh 18650 lithium battery INR18650S"
"Rechargeable Lithium ion Battery INR18650S-2500mAh Power Type 3.6V 2500mAh 3C 7.5A discharge current"
Dunno if they are the same as your cell.
with item titles like
"ZhuoNeng INR18650S-2500mAh Power type 18650 lithium-ion cell 3.6V 2.5ah 2500mah 3C discharge for e-bike/LEV/ESS"
"Battery 3.6v 2500mAh 18650 lithium battery INR18650S"
"Rechargeable Lithium ion Battery INR18650S-2500mAh Power Type 3.6V 2500mAh 3C 7.5A discharge current"
Dunno if they are the same as your cell.
For that, you should be able to go by the previously-known battery specs. If the battery was marked as capable of 1600w, then assuming that's continuous it would be 1600w / 48v would be 33A, so the BMS would need to be limited to a 33A shutdown to protect the cells the same as the old one. (it can be and should be capable of more, so it doesn't blow up under spikes of load, but it should be limited to shutdown at that limit, after maybe a few seconds of higher than that).
If you can tell how many parallel cells are actually in the pack then if we go by the current listed on the specs I saw, you would multiply that p number by that current (7.5A), to get the max current the cells should handle. They don't specify if that 7.5A is continuous or peak; so you'd have to either test or assume.... Testing means putting a continuous load on the cells equal to the number of p cells x the current you want to test them at, and monitoring temperature and voltage drop vs no load. If temperature goes up rapidly or voltage drop is severe then that 7.5A should be used as a peak rating, if temperature rises only slowly or voltage drop is minimal, it is probably continuous.
Since it's marked as 13Ah, then if they are 2.5Ah cells, that gives 5.2p, which doesn't work. So it must either be 6p, and they are derating the Ah, or more likely it is 5p and they are exaggerating the Ah (because we all know no company would ever do that
).
If it's 5p, then 5 x 7.5A is 37.5A. If it's 6p then 6 x 7.5A is 45A. My guess is that the 7.5A is really a peak rating (regardless of how it's advertised).
The 48v, if used the way most packs are specified, means it needs to be a 13s BMS, not 14s, since those cells are marked as 3.7v (nominal; they'd be 4.2v full). 48v / 13s = 3.7v.
If you can tell how many parallel cells are actually in the pack then if we go by the current listed on the specs I saw, you would multiply that p number by that current (7.5A), to get the max current the cells should handle. They don't specify if that 7.5A is continuous or peak; so you'd have to either test or assume.... Testing means putting a continuous load on the cells equal to the number of p cells x the current you want to test them at, and monitoring temperature and voltage drop vs no load. If temperature goes up rapidly or voltage drop is severe then that 7.5A should be used as a peak rating, if temperature rises only slowly or voltage drop is minimal, it is probably continuous.
Since it's marked as 13Ah, then if they are 2.5Ah cells, that gives 5.2p, which doesn't work. So it must either be 6p, and they are derating the Ah, or more likely it is 5p and they are exaggerating the Ah (because we all know no company would ever do that
).If it's 5p, then 5 x 7.5A is 37.5A. If it's 6p then 6 x 7.5A is 45A. My guess is that the 7.5A is really a peak rating (regardless of how it's advertised).
The 48v, if used the way most packs are specified, means it needs to be a 13s BMS, not 14s, since those cells are marked as 3.7v (nominal; they'd be 4.2v full). 48v / 13s = 3.7v.
Theodore Voltaire
1 GW
Wow. 40 amp. I was thinking it would be 25 or 30
To safely use (without stressing the cells) a 40A (continuous) BMS on a pack of those cells, assuming the info I found is for those, it'd need to be at least 6p groups, and the 3C rating (7.5A) per cell would need to be continuous (with an even higher burst rating that isn't specified in the pages I looked at)--that would give the pack a 45A continuous rating.
Otherwise, the rating is less than 40A, and a 40A BMS (assuming it's rating is also continuous) will allow the pack to be stressed by any controller that is also rated to allow 40A or more continuous, assuming a load on the system that will draw that much (which in this thread is pretty likely :lol: ).
Even if the cells aren't meant to be run that hard, it's not likely they'll catch fire or anything, but they will sag in voltage excessively under that kind of load, so you often don't really get any more power out of it above some current below that level--drawing more current causes so much more voltage sag that the A x V ends up the same watts at the higher current as a lower current.
They also won't last as long as they would otherwise, being stressed harder heats them up more which ages them faster and lowers their capabilities more quickly.
Otherwise, the rating is less than 40A, and a 40A BMS (assuming it's rating is also continuous) will allow the pack to be stressed by any controller that is also rated to allow 40A or more continuous, assuming a load on the system that will draw that much (which in this thread is pretty likely :lol: ).
Even if the cells aren't meant to be run that hard, it's not likely they'll catch fire or anything, but they will sag in voltage excessively under that kind of load, so you often don't really get any more power out of it above some current below that level--drawing more current causes so much more voltage sag that the A x V ends up the same watts at the higher current as a lower current.
They also won't last as long as they would otherwise, being stressed harder heats them up more which ages them faster and lowers their capabilities more quickly.
Theodore Voltaire
1 GW
I went on the most fun ride last night with a group of fast eUnicycles. We rat raced around Oak Cliff. Of all the electric contraptions I've ridden with, they're most fun. They like to go fast on the street. All the other groups just want to putt along on the city trails. These guys go too fast to do that.
Theodore Voltaire
1 GW
Someone posted a video of the EUC ride I was on. These things go 40 to 50 mph
Theodore Voltaire
1 GW
For a long time it used to bug me that Stealth's are so rare, but now that there's getting to be so many eBikes coming to group rides it's become kind of cool. It only took 10 years to get to this point.
Sure. You throw a rope with a hook on it up to the top and get the cable tangled in your rear wheel. Hang on tight to the bike and twist the throttle. :lol:
Rix
100 TW
Yes, get a run at it, let momentum carry you. If you crash your bike, relax, the ole man is a Television repairman, he has this ultimate set of tools, I can fix it.
Theodore Voltaire
1 GW
