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Discussion Starter · #1 ·
Hello,

I'm converting a Ninja 250 to electric, with 24 CALB 40Ah Cells.

My MiniBMS arrived today, prompting the first of what I expect will be many questions....

The boards look like they are sealed against moisture - how much moisture can they tolerate? Is a few drops of rain or dribble of water from a splash through a puddle OK?

In the recommended set-up the MiniBMS draws power from an aux battery. In a motorcycle where space and weight are precious - would there be problems running an always on DC/DC converter instead? My only fear with that is the possibility of a continuous load on the batteries if the bike is resting uncharged - but with the only thing drawing current from it being the MiniBMS, that should be miniscule.

Thanks
 

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Bill,

moisture resistance is difficult to quantify in this case, since BMS modules sit directly on top of the battery cells, with battery terminals exposed to same elements as BMS modules. Just like you would not want too much moisture on and around your cell terminals, same applies to BMS modules.

I have mine completely exposed under the hood and often get damp after driving in the rain, without any issues. However, one customer had a failure when water collected on top of the cell and BMS module shorted out.

I advise to take reasonable steps to protect battery tops and BMS modules from the elements, even though it does not need to be completely sealed off.

Powering BMS from the main pack via DC-DC converter with 12V nominal output is perfectly acceptable, many people have done so.

Head end controller draws about 50mA at 12V, which will be even less at the pack level, so its not an issue if the bike is regularly used and charged. If you plan to store the bike for extended periods, you can disconnect everything from the pack.

Hope this helps.
 

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Discussion Starter · #4 ·
And as battery arrival draws closer, I find myself flip-flopping on whether I want to carry an aux battery or run with a DC-DC converter. That prompts another question about charging - am I correct that the 12v power requirement of the MiniBMS main board has plenty enough flexibility to deal with voltage rise and fall of voltage through discharge sag and charging?
 
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