Originally Posted by England-Kev
Ok, let's talk batteries.....
My Ambo has a battery that could start a 757, I have never seen a bike with such a large battery, but do they need one that size?
What are you guys running in your bikes? I see the Ritmo racer has a much smaller Yuasa sealed battery, is this the way forward?
What battery you need depends on a few things, the most important is likely what starter you have. Both the Bosch and Marelli units like big batteries/cranking amps, while a Valeo can make do with something smaller.
My favorites for Marelli and Bosch equipped bikes are the Odyssey PC925 (if the customer can afford one - $166 here), the YIX30L/ETX30L originally used in Harley FLH models (approx. $95 here) and the battery originally meant for the Mazda Miata (about the same $$). Some folks don't like the automotive style posts of the Miata battery, but I do as I feel they make better contact and deliver more punch that the others. The Miata battery also fits well into the original holddown frame if you still have that.
The one currently (no pun intended) in my '69 Ambassador is an AC Delco 55-6, meant for a Ford Maverick and a few other US crapmobiles. That size is no longer made, which is a shame, because it only cost me $55 back in '04 (yes, it's now 8 yrs. old). Never had a battery tender on it, never needed a charge. Big and heavy, but then so is the bike. Going to great lengths to save 10 lbs. of battery weight is a bit silly IMO.
Some especially "frugal" folks use the U1 sized garden tractor battery. If you go that route, please buy one that is sealed (doesn't vent out the top). Acid damage is never pretty...