NickTH

I have a Corvette battery charger, same as CTEK 3300 charger that I've used on my Vette. It plugs into the lighter/acc plug in the trunk that's always on, not plug in dash since that cuts off when not running.

Luckily, I've never had battery issues so far on my wife's 2015 E400. It's now 2.5 yrs
But my concern is the numerous short drives, usually 1-2 miles trips.

The batteries in all my previous cars, usually lasted 3 - 5 yrs, before replacement.

So, just wondering if I can still use the same charger for the E400, & where's an always on acc plug?

Thanks,

fosterelli

I believe CTEK makes the MB-branded accessory charger/maintainers.

I don't know if there's an always-on or not. But if not, you can always go this method:
Nice thing about this is you can mount it in a bunch of different places for convenience.

You could also convert one of your outlets to constant, just tap into a hot lead of similar amperage and take it to the outlet (head unit will have a constant).

I change our batteries every 3 years no matter what. This Texas heat cooks 'em and once I was stranded - so now it's a scheduled changeout for me!

But hopefully someone will know of an always-on plug for you.