Originally Posted by Tim_in_NJ
Thanks for the comment, I've give it a shot in the morning- While I was still researching and waiting for an swer to my plea I found other observation slike your. There was some chatter about using two Ford relays as a work around to the OEM updated part. What's your thought about this?
Also will a car charger trash my Gel battery if I put it on over night?
A larger automotive relay will certainly work, but I would not do that to my bike since there is a BMW "fix", although fairly expensive. If the bike is sold, or taken to a dealer for any service the modification could cause a bit of confusion.
To be safe I would not use a car charger on a Gell Cell battery. Gell cell batteries are the most picky about charge voltage of the three types, flooded acid, gelled electrolyte, and absorbed glass mat.
Flooded acid is the cheapest, but requires careful maintenance. It can take the highest overcharge without damage as long as the electrolyte level is never allowed to drop below the top of the plates.
Gell Cell was developed to avoid acid spill and outgassing, but there are some limitations. They cannot be deep discharged, and can be easily overcharged to the point of damage. They need much better voltage regulation of the charger. Typically 13.2-13.4 volts.
Absorbed Glass Mat (AGM), such as Odyssey, are the best of the bunch, but more costly. AGM batteries can use the same chargers that flooded acid batteries use, can charge at a higher rate than Gell Cell, do not self discharge like either flooded acid or gell cell do (they can sit for MONTHS without being charged), and they can take the deepest discharge of any and not be damaged, down to 20% capacity, where lead acid or gell cells would have their life reduced.
To me, BMW going to Gell Cell was a step in the wrong direction. Less maintenance required, but far more sensitive to over charge and deep discharge.
My pick is the Odyssey or Westco AGM battery. I would not purchase a Gell Cell in a bike. If I buy a bike with a Gell Cell in it, I would continue to use it until it showed the first signs of any problem, then it would be replaced with AGM.