Baltneu wrote: ↑
Wed Apr 15, 2020 12:16 pm
I have not driven my 2018 SL in 3 weeks due to the current situation.
When I was in the garage earlier I noticed one of the 3 blue charging lights was flashing. It went off after a few minutes.
I am pretty sure this means the 12V battery needed a charging and the traction battery was doing the work.
Is there anything we should do with our batteries to preserve good health to them since we will be driving less?
General consensus seems to be a qualified "No" on the later models such as yours. Store the car longer term with roughly 50% charge on the traction battery. It should keep the 12v adequately, if not ideally charged by itself - the 12v charging algorithm seems to have been improved over the years to where many of us don't experience problems. Some have, however.
If you're looking for something to do, put the 12v on a "battery tender" - a small, smart charger that won't overcharge it. We've done that on both of our conventional vehicles, since we're not driving them, and they won't charge at all otherwise. Not too expensive, and useful. A "dumb" charger that just charges away without limits, however, will do more damage than good. Overcharging is just as bad as undercharging. Make sure your battery tender understands when to go into "float".