I drive my SL500 once or twice a week over short distances. At each start-up the "Consumer battery off-line" displays in the dash panel. After a couple miles the display extinguishes. This occurs at each start-up. I'm considering using a maintainer. Model #12117 BatteryMINDer looks Interesting because it also is a desulphator. Has anyone used this or a similar product? I'm concerned that such a device could fry the circuitry if it's used with an installed battery.

 

check out my response to Masmas on this site...
there are better chargers for less money than the one you mention, but it should do the job,.

glen