Non-Tdm : Batteries - Does Size Matter?

[steve27bha]

My signature shows I have two other bikes, a Honda CBX750 and a Cagiva N90 125. The CBX has not moved for a while. The Cagiva has lain in bits for far too long and is currently being screwed back together. Neither bike has a battery.

 

The batteries specified are different - as you would expect given the difference in engine sizes - but the case sizes are the same for width and height, and only differ in the larger CBX item being 90mm deep/thick vs the Cagiva's 80. I think the latter's space can take the extra of the former - bodywork will determine this when fitted. They differ in capacity at 14 vs 9 Ah for Yuasa. (Motobatt claim 16.5 vs 11!)

 

The question is:- Can I use the bigger one in the smaller bike?

 

I can't think what harm may be done other than the small generator putting out a weak charge, but that output will / should keep up with the smaller demand. Bigger should  keep it runninng a bit longer if the generator packs up! - I've heard about Italian electrics!

 

I would appreciate informed opinion / knowledge before taking the expensive route of buying two batteries.

 

[Trevini]

I'd in the, "if it physically fits, go with it". The difference between them in terms of power isn't significant and the charging system will be fine. If anything, you'll give the electrical system an easier time if drawing a high load as it'll act a a bit of a buffer. I don't know what the alternator is rated at, but if it's 30 amps, it'll put that into any battery without caring what size it is and won't care. 

[Sphere]

Your bike's electrical system won't care what the capacity of the battery is, only the voltage matters.

 

Go for the big 'un.

[Snowbird]

:wifgeni:

The charging system only has to keep up with the power used, having a bigger battery will just mean it less discharged in the first place.

Assuming both are 12v of course.

[steve27bha]

OK folks, I thank you for the reassurances. Careful measuring will follow.

[Trevini]

If you haven’t sussed it already and the battery is a bit of a tight fit, make a tab with gaffa tape to lift it out more easily. 

[steve27bha]

The access is clear from the side - here's the current (!) state of play:-

 

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