When I first got my 1979 R100RT the prior owner told me, to use a cheap U1-3 lawn tractor battery, so that's what I bought. 18 months later, I understand he wasn't so much of an Airhead guru as I once gave him credit to be. The 30Ah lawn tractor battery works, but it's sloshing acid all over the terminals and thus causing all sorts of battery terminal (and thus battery voltage) issues. It's also too tall and striking the bottom of the tool box.
Now I've got to replace both battery cables due to terminal corrosion, so I've decided to buy a real motorcycle battery of the SLA type too. I don't want to spend a fortune, but can definitely see the advantages of a truly sealed battery that's been well made. The orange Odyssey brand and yellow Motobatt brands I've seen come into the shop show ZERO leakage, and that's impressive.
► So what other brands don't leak that fit the big (7.6 x 5.1 inch) RT battery tray ?
► Do I really need a 30Ah battery, or will a 20Ah PC680 give good service ?
► AGMs will need a slightly higher charge voltage. How do I accomplish that with a stock system ?
► What's the favorite battery supplier ?
School me please.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
All of these work fine. I'm currently using a Mega Crank MTX-30L from batterymart.com which cost $90. I've had great experiences with Odyssey batteries; this new battery is untested, but working well so far. I also recommend buying from http://www.rubberchickenracinggarage.com, as Tom Cutter is a frequent and very knowledgeable resource on the email list.
A smaller PC680 will work fine, as long as your electrical system is in good repair, and the bike is in a good state of tune so it starts promptly. You will save a few pounds in weight, but why risk getting stranded if you get a bad load of fuel or something, and have a hard time starting the bike?
I am not having any issues keeping an AGM battery charged with the stock charging system. Just make sure all contacts and grounds are clean.
Many thanks, my friend.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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