Downtube battery fit question
03-02-21, 01:49 PM
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Downtube battery fit question
Working on my first ebike, a rear geared hub drive 500W 48V Bafang kit on a 29er flat bar hybrid bike. Am looking at batteries, and want the best range I can get.
I'm considering a hailing max 48V 21.7Ah Chamrider with Samsung 33G cells. I made a cardboard cutout with the dimensions of the battery. It looks like it would fit, but it's close and depends on two issues:
1) How much room do you need at head of battery to slide it on and off the contacts
2) How much does the mounting plate add to the height of the battery case
Educated guesses from those with experience are welcome. Are there rules of thumb on how much extra space to allow to be safe?
I'm considering a hailing max 48V 21.7Ah Chamrider with Samsung 33G cells. I made a cardboard cutout with the dimensions of the battery. It looks like it would fit, but it's close and depends on two issues:
1) How much room do you need at head of battery to slide it on and off the contacts
2) How much does the mounting plate add to the height of the battery case
Educated guesses from those with experience are welcome. Are there rules of thumb on how much extra space to allow to be safe?
03-02-21, 02:10 PM
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I'm using a Luna battery that is "attached" magnetically in the "water bottle cage" area of the down tube, and used Wolf Tooth Components "B-Rad" mounts to move the battery to where it had enough space. The "side-mounting" feature of the battery may make it more easily placed. I'll fool around with "head space" and see how much is needed.
OK checked my system and looks like 1" - 2" of space is needed, but probably closer to the lower figure.
OK checked my system and looks like 1" - 2" of space is needed, but probably closer to the lower figure.
Last edited by 2old; 03-02-21 at 10:09 PM.
03-03-21, 06:49 AM
#3
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The battery mount adds about 3/16 Inch 5mm. The battery slides forward about and inch 25mm then lifts up another 3/16" or 5mm
You can fit a much larger triangle battery in that space. I assume you are looking for very long range. A 17 amp hour battery on that bike will get you 80 miles 130km if you are pedaling. Assuming a speed of 15-16 mph 25kph
You can fit a much larger triangle battery in that space. I assume you are looking for very long range. A 17 amp hour battery on that bike will get you 80 miles 130km if you are pedaling. Assuming a speed of 15-16 mph 25kph
03-03-21, 07:54 AM
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If you jump from Samsung 31G cells to Samsung 35E cells you will get a slightly smaller battery at 21 amp h
3.1* 7 = 21.7 amp h and 3.5*6 = 21
One battery has 7 parallel banks and the other has 6 parallel banks. 13S-7P vs 13S-6P The smaller battery will weight less also.
3.1* 7 = 21.7 amp h and 3.5*6 = 21
One battery has 7 parallel banks and the other has 6 parallel banks. 13S-7P vs 13S-6P The smaller battery will weight less also.
