Mighty Max battery - failed

[gordonv]

I couldn't find any history on it, except for a post back in 2019 when I first heard of this battery, so less than 5 years old, and it's crapped out. By my records, maybe 3.5K miles. Maybe why it failed? I did keep it charged up and disconnected from the bike. I added close to 8 oz of water to the cells, before trying to recover the battery.

Shows 12v but it won't turn the engine over. Jump start, runs, warmed up, off, and try to start, and still nothing.

I found an inexpensive LiFePo battery on Amazon.ca, less than 1/2 the price I paid for one for my GW back a while ago, so I thought I would spend a little more on myself and buy it.

It's very small, but rated for 240 CCA and 6 Ah, Had to block it up so I could connect the leads above the battery tray.

At least this time I documented the purchase/install in my notes for the bike, and see how long it lasts for.

Kemi Moto
https://www.amazon.ca/dp/B0D3DJJMF2?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Some other sizes offered, was thinking of the cheaper 4 Ah battery even, but settled on something more than the stock lead acid battery ratings, rather than less.

[h13man]

My 7yr. old Yuasa needed a charge a while back thus I keep the tender on for now but I'll be buying a Duracell AGM from Sam's. Ready to go w/o doing acid fill though I always put a 2 amp charge to all new batteries and my tractor battery every time as it sets a lot.

[F6Dave]

I just bought one of those for my 1988 BMW R100. It uses a very large (30 AH) battery that rarely lasts 2 years, even if left on a maintainer. In the recent past I've tried the OEM Yuasa and an aftermarket Continental from the local farm and ranch. Both cost about $130 and neither made it to 1-1/2 years. So I just bought a Mighty Max for $80. Even if it dies in a year I'll be no worse off than with those others.

I'm not sure why that old bike is so hard on batteries as there's nothing to drain it when it sits in the garage. Maybe it's the huge automotive starter it uses, which was shared with some European cars of the era. The fact that BMW included a charger and external charging jack on the bike was probably a hint.