battery charger

does anyone have recomendations for the use of a trickle
or float charger on  SL..the owners manual discourages it.
i dont drive  mine much in winter and the trunk battery
gets low enough for the battery  off line alert to come on.
 
help..
glen

I just pull the ground wire on the battery when I let her set for more than a few days.  With those cars pulling power all the time the batteries today don't stand up to getting drained and charged all the time.  So far I've had no problems at all by pulling the ground.  The battery is always ready to go when I want to take her for a spin.  I use a trickle charger, but I disconnect the cables. 

thanks..
if  you pull the ground,  dont you loose some of the programming of  the accesories?
im talking about the  trunk battery...
 
tnx
glen

Glen, take a look at Yuasa's smart charger.  It's either 1.25A or 1.5A.  Maintenance float charge drops to 10mA :)

you have to reset your clock,  push memory for your seats, mirrors and steering wheel, no biggie if they are still in the same position as before.  reset your radio.   Small sacrifice to save your battery.  Is there a battery somewhere other than the trunk that I'm not aware of?

thanks all...
im using a  low current vector/black and decker  charger  that float charges at 12.7-3.2 volts..and when balanced it is only putting 10- to 50 ma  to maintiain memory devices.
and so far ive only used it on the appliance battery in the trunk....and yes the 2003 sl 500 has a start batttery up front and a 70 ah unit  in the trunk that runs only the ""appliances"
...interesting to note...the mercedes battery  seems to be made by johnson controls.
 
tnx
 
glen
 

well that's something I didn't know about the 230 having a second battery.  seems like a good feature over my old 129 with the one battery for all functions.  BTW those 230s are really gorgeous. 

sorry...i may have confused some....its a 2003   SL500.
that has the 2 batteries.
glen