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Battery

Posted: 16 Sep 2023 16:05
by Stempy
What batteries is everyone using for a 500 sport?
Starting to think the Odyssey PC680 is not man enough?

Re: Battery

Posted: 17 Sep 2023 15:52
by 3potjohn
That is not my experience with my Sport nor my BMW airheads. If it can crank a pair of 500cc cylinders in Winter it ought to be good enough for a Morini. Is it fully charging?

Re: Battery

Posted: 17 Sep 2023 16:12
by morini_tom
I’m guessing your query is because you’re having starting issues?

Most decent modern batteries (especially AGM butteries like the odyssey) will have higher cranking capacity than anything available when these bikes were new.

However no matter how good your battery, it all struggle to start if the engine, starter motor or starter
Motor relay are in poor health.

Although they can be problematic, the starter motors can be made to work well and reliably. If you don’t know when yours was last overhauled (or at the very least, had its oil changed) then I would suggest this be your first port of call.

Secondly, the later type laminated starter shoes are a massive improvement on the first solid ones, and are a worthwhile upgrade if you don’t have one.

Other than more metal to get spinning, there’s no difference between the 350 and 500 in terms of starters and the associated power requirement so have a look on the forum for battery and starter info for the 350 as well as the 500.

Of course, any prospective battery you may fit you should check the size against what you can fit in your frame as there were differences between models over the years.

I have a Motobatt MB51814 in my ‘82 350 sport and it is most excellent at starting.

A further point of note- AGM batteries such as yours require charging at something like 40% of the battery’s C10 rating. So for your battery that’s about 6 Amps at 14.7 volts. Too often people try to use maintenance chargers, optimates etc which are okay for keeping a full battery full but have nowhere near enough wallop to charge these type of batteries, and will show full when actually the battery is just not accepting a charge from the feeble charger. If you don’t have a charger capable of in excess of 6 Amp charging then you’re on a hiding to nowhere. Odyssey provide really good data sheets and technical info for their batteries so have a read up on the specifics for your battery if you think maybe this could have been your issue.

The above isn’t to say don’t get a new battery, it’s more to say that a new battery might only hide some other underlying issue for a short while

Re: Battery

Posted: 23 Sep 2023 19:57
by Stempy
Well my battery is man enough but my bronze starter gear isn’t , starter motor rebuild time 😀😀