Best way to charge car battery?
Banned
Joined: Oct 2005
Posts: 4,957
Likes: 1,640
I can tell you that when I have not had the car on a trickle charger and not driven for a few weeks my ECO S/S light will generally not illuminate until I have driven for a pretty long distance. On the other hand if I have had the car sitting on the trickle charger for a day or two and head out, the ECO is illuminated and goes green within the first couple miles of driving.
MBWorld Fanatic!
Joined: Jun 2020
Posts: 1,363
Likes: 1,012
'11 E350, '11 E550, '98 M3, '95 E320
I can tell you that when I have not had the car on a trickle charger and not driven for a few weeks my ECO S/S light will generally not illuminate until I have driven for a pretty long distance. On the other hand if I have had the car sitting on the trickle charger for a day or two and head out, the ECO is illuminated and goes green within the first couple miles of driving.
Member
Joined: Oct 2017
Posts: 158
Likes: 25
From: Marin County,California
2016 E350 Sedan
The Aux battery will not charge until the Power Relay tells it to charge, so using a trickle charger on the main won't keep your Aux battery charged.
The Power Relay looks at main battery voltage and aux battery voltage and has a timer that kicks in after about 15-20 minutes of driving, if the voltages meet requirements. That is what connects the Aux battery to the main battery for charging. So, if you don't drive the car, the aux battery will eventually go dead. Only way around that is to specifically charge the Aux battery itself.
.
The Power Relay looks at main battery voltage and aux battery voltage and has a timer that kicks in after about 15-20 minutes of driving, if the voltages meet requirements. That is what connects the Aux battery to the main battery for charging. So, if you don't drive the car, the aux battery will eventually go dead. Only way around that is to specifically charge the Aux battery itself.
.
Last edited by Alandf; Mar 4, 2021 at 11:57 PM. Reason: spelling
MBWorld Fanatic!
Joined: Dec 2020
Posts: 2,412
Likes: 1,483
From: 122W, 37N
2016 E350 4Matic wagon, 2019 Ford Expedition, 2019 Chevy Bolt EV
install a pair of battery tenders, a junior for the aux battery, and a regular size one for the engine battery, and wire them to a single power cord, so you can just plug the car in when its parked in the garage for awhile.
new world problems.
new world problems.
Banned
Joined: Oct 2005
Posts: 4,957
Likes: 1,640
Does the W213 still have two separate batteries or did MB go to one battery like every other manufacturer?
edit: I guess the answer is no. There is a voltage converter now in place of the trunk battery.
edit: I guess the answer is no. There is a voltage converter now in place of the trunk battery.
Last edited by RA72825; Mar 5, 2021 at 10:43 AM.
MBWorld Fanatic!
Joined: Apr 2006
Posts: 4,695
Likes: 1,830
From: Dallas-Ft.Worth,TX
2016 E350 Sport
...and, how do you charge a "Voltage Converter?" LOL
