G'day everyone I've recently acquired a '56 BMW R50 from an uncle. It has been pulling a sidecar which is now not with the bike. To help the chair along, at some stage the engine was upgraded to a '71 R75/5. In the past the battery for this setup was carried in the attached sidecar. I will run the bike as a solo, so bought a sealed battery to suit the R75 engine. This battery is smaller than an original 1971 spec battery… but doesn't fit in the available space between the engine and the rear mudguard. Frame too small, engine too big! So. I rang a battery specialist and he will sell me a Deka battery which will fit the available space. The R75/5 battery should be 12v and 18Ah, this new one will be 12v but only 8Ah. The Cranking amps appear to be in an acceptable region (around 300), so I should be able to start the bike, but will I cook an 8 amp battery by running it in the bike? Don't really fancy acid burns. Advice appreciated - thanks.