# Can I get a universal ebike battery



## Leemi1982 (24 Jun 2020)

Hi I have a carrera vengeance ebike just wondering about a second battery do I have to get the manufactures own battery or is there a universal battery I can buy... bosh seems to keep popping up. 

I just checked my battery health it’s showing 80% after a full charge, bike and battery are only 2 weeks old only had 3 charges from new???


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## raleighnut (24 Jun 2020)

Leemi1982 said:


> Hi I have a carrera vengeance ebike just wondering about a second battery do I have to get the manufactures own battery or is there a universal battery I can buy... bosh seems to keep popping up.
> 
> I just checked my battery health it’s showing 80% after a full charge, bike and battery are only 2 weeks old only had 3 charges from new???


They need to fit the same mounts and have the same contacts (position and polarity) then there is the charger compatibility.


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## welsh dragon (24 Jun 2020)

I don't think you can change to another battery.


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## cyberknight (24 Jun 2020)

if its down to 80 % after 3 charges i would have thought you could have taken it back.


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## Leemi1982 (24 Jun 2020)

Yeah I took the battery into Halfords yesterday and the guy seemed a bit clueless To what I was showing him so he got the manager out he seemed no better. they compared my battery to a display model in shop and said that they show the same. Felt a bit fobbed off walking out


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## raleighnut (24 Jun 2020)

cyberknight said:


> if its down to 80 % after 3 charges i would have thought you could have taken it back.


80% is the optimum charge level for longevity of the battery, it's what most manufacturers recommend


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## CXRAndy (25 Jun 2020)

If your charger is stopping charge at 80% of maximum then its protecting it from over charging.

Most li-ion cell batteries are 3.6 Volts nominal voltage, fully charged at 4.2 Volts.

Im assuming that your bike is a 36 Volt battery, so nominal charge is 36 Volts. Peak max around 42 Volts. It will be a 10 cell series design with several of these in parallel to give increased current capacity.

Charge your battery and measure voltage at the point is reached fully charged on the charger, it should be 42 Volts and definitely 36 Volts and more.

Take battery off bike and use digital meter on terminals


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## Levo-Lon (26 Jun 2020)

Quote of the day.".halfords staff seemed clueless"


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## Levo-Lon (26 Jun 2020)

Quote of the day.".halfords staff seemed clueless" 

You probably can buy a generic battery as the fitting bracket on on the frame bikes are detachable on some bikes like older Bosch


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## ebikeerwidnes (26 Jun 2020)

How are you measuring the battery health?
If you are just using the meter on the battery/bike then it should show fully charged - if not then the shop should change it

DO not trust the demonstrator battery - I have seen a few ebikes in Halford that have been sitting there for a while without being used - and the batteries don;t really like that


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## cyberknight (29 Jun 2020)

raleighnut said:


> 80% is the optimum charge level for longevity of the battery, it's what most manufacturers recommend


fair enough


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