48V pack for BBSHD (1000W motor) using 18650 2550mah Cells Molicel

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andr333y

New member
Joined
Jan 4, 2022
Messages
1
Hi, I am planning on building the pack for BBSHD mid drive motor for my ebike conversion.

pack would be 48V 13S 7P
using 18650 2550mah Cells Molicel
Those batteries rated at 4A <= 60C and 5A<=45C

I understand the pack should be able to deliver 30a, because that's what the motor is rated for.
Would those batteries be enough?
 

OffGridInTheCity

Active member
Joined
Dec 15, 2018
Messages
1,869
Hi, I am planning on building the pack for BBSHD mid drive motor for my ebike conversion.

pack would be 48V 13S 7P
using 18650 2550mah Cells Molicel
Those batteries rated at 4A <= 60C and 5A<=45C
Is this max rating? - could you post a spec?

I understand the pack should be able to deliver 30a, because that's what the motor is rated for.
Could you post the wattage of your motor(s)?

Would those batteries be enough?
I don't say this to be discouraging, just sharing discussion...

In my experience, cells with a 4a max rating / 600ma standard rating (laptop cells) don't do well over 1a. At 1a, 7p would be 7a * 48v = 336w. If you pull a 700w surge (2a/cell) you may see the 4.15v/cell charge drop to 3.7v/cell (or something like that) instantly on power surge - and then drain down to 3.4v/cell rapidly. In other words, it might work to a degree but you may not be happy with limited range.

This is why folks use 10a or 15a max discharge cells for this type of thing - the voltage doesn't pull down so dramatically / shorten the usefulness of the battery. For example - https://www.batteryclearinghouse.com/products/30-cells-high-grade-lg-mh1-10a-3ah-cells-in-10s3p-pack - notice 10a continuous discharge.
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If you could make the batter larger as in 14p or 21p it would help a lot using low-amp cells.
 
Last edited:

floydR

Member
Joined
Aug 23, 2017
Messages
1,360
I would use escooter/ebike cells such as these https://www.batteryclearinghouse.co...asonic-ncr18650bd-10a-3ah-cells-in-10s3p-pack https://www.batteryclearinghouse.co...high-grade-lg-mh1-10a-3ah-cells-in-10s3p-pack https://www.batteryclearinghouse.co...2600mah-10a-lithium-ion-cells-in-rubber-packs or these in a prebuilt 13 s pack https://batteryhookup.com/products/2-pack-panasonic-48v-power-module-13s-6-4a-299-99wh from what i have read the 13s 48v packs have fewer controller failures than the 14s 52v packs. If you are not in the USA or Canada these would not be a good deal
later floyd
 

DiggsUt

Member
Joined
Oct 30, 2019
Messages
81
Could you post the wattage of your motor(s)?

The BBHSD will pull over 1600 watts at peak through its stock controller.

If you could make the batter larger as in 14p or 21p it would help a lot using low-amp cells.

Anything past 6-7p (@13 or 14s) on an ebike becomes rather unwieldy. Although I run 9p it is split between two packs. One on the downtube and one on the rear rack but I am a country cruiser. The guys on dirt like to keep it much lighter.
 
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