Airhead Batteries, not R65

[montmil]

The battery in my 1978 R100S was pretty funky when I acquired the motorcycle. The unit is a flooded-style battery from Bikemaster and had four of the six fill caps destroyed. I was able to top up the very low electrolyte with distilled water but had to permanently seal off the boogered up caps.

I keep the all the bikes on a Battery Tender and this has allowed a small drop in the acid levels of the flooded battery. It was just a matter of time...

Having decided to maintain the same style, size and AH battery, I started searching for a replacement. Naturally, quite a few "name" battery providers had discontinued the battery I needed. The R100S has a steel "large tray" battery holder. The spec battery is a 25AH BMW part # 61 21 1 459 650 that lists for close to two C-notes!

After quite a bit of time on the compuKer, I checked in with a supplier that had previously provided an exact spec and fit battery for my Triumph 900 at a very reasonable price. Urethra! Fifty-six bucks plus shipping. My kinda deal.

There are quite a few R65 forum members that own Slash Series Airheads. Batteries prices can get pretty outrageous. I'm glad I shopped around.

http://www.staabbattery.com/product/Yuasa-Motorcycle-Battery/Yuasa-Y60-N24AL-B-Battery.html

Anton Largiader (large-a-DARE) provides some excellent BMW battery info on his website.

http://www.largiader.com/articles/battery.html

[Armen]

FWIW, the last big twin I worked on we installed an upgraded starter (ND, Valeo, and EME all work well). This not only weighs about 5 lbs less, but allows the use of the smaller 18AH battery. On one bike we did a Shorai LI battery as well, which weighed about 4 Lbs. Another 20 Lbs lost.
The stock electrics were marginal 40 years ago, and sucktacular now.
I've got the Enduralast alternator and later starters on both of my airheads. The bike charges at idle!
And the battery can be removed without major agony.
-Armen

[montmil]

Armen, It would be difficult for me to justify spending around $350.00 for one of those lightweight, zippy NiponDenso starters just to get a smaller AH battery. Staab Battery is free shipping me a new batt for $56.00.

[Armen]

Bought one of the Euro Moto Electrics starters for about $125.  It was always such a hateful task to pull those boat anchor batteries.
I've got a 5 year old AGM 18AH battery in my '91 R100. When it dies I'll go to a 3 lb Shorai like the one in my 900SS Duc.

[Justin B.]

I am running the same battery in my R100 that I do in the R65s.  When I still had the original battery box I just made a spacer to take up the slack and afterwards I installed a modified R65 battery box.  The picture is with a PC680 but it currently has the smaller battery from Staab...