I'm sorting out a 350 Goldie, still not got the charging circuit sorted but I've had 2 battery failures. Could the vibration be the problem? Both batteries were standard lead acid ones, the same as the original, the old one still works OK ish but the new ones lost a cell after about 10 miles (4.3 volts and no charge). Suggestions very welcome!
When I started at Simsmetal in the 70's battery grids were 2mm to 3 mm .
When I left 4 years latter they were 0.5mm thick.
Back when I was living with my parents a heavy duty 13 plate battery was a 2 man lift, now days I can carry 2 of them comfortably and I am nowhere near as strong now as I was then.
So mechanical damage is high particularly on our shakey old bikes.
By far the best type of battery are the PVR AGM type
Pressure Valve Regulated prevents them from gassing
Adsorbent Glass Mat supports the grid plates while allowing free flow of ions in the electrolyte.
And from a mechanical point of view the spiral cell batteries are streets ahead.
For bikes like yours that run magneto ignition you can also get away with with a gell cell because unless you are a real horn jockey or like to melt the bitumen with 10kW of intense white light, the amperage demands on the battery are quite modest.