SL55/63/65/R230 AMG: Proper "disconnect / connect / reconnect" sequence for battery installation requested
01-07-2019, 09:40 PM
#1
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2016 S63 Coupe & 2014 E550 4MATIC Sedan
Proper "disconnect / connect / reconnect" sequence for battery installation requested
Proper "disconnect / connect / reconnect" sequence for battery installation requested please.
Hello all, I hope you are having a great day so far!
I have a 2009 SL63.
I wish to install a battery tender (CTEK of course!), and I wish to install the semi-permanent eye hook cables, one to the battery, and the negative to the mounting point on the car if possible.
However, I think the electrical system might not like "any old random order", and I know there is a "specific" way, but I am just not sure what it is.
For the record, ha, yes, I did check both the MY09 Owners Manual, as well as the "Maintenance Booklet", but of course, they were of no avail.
I suspect it is this:
TO DISCONNECT:
1. Disconnect negative terminal cable from the starter battery. (leave battery in place.)
2. Disconnect negative terminal cable from the main battery in the trunk.
3. Disconnect positive battery cable from the main battery in the trunk.
TO RECONNECT:
1. Connect positive battery cable to the main battery in the trunk.
2. Connect negative terminal cable to the main battery in the trunk.
3. Connect negative terminal cable to the starter battery.
I understand there is a "special way" to not disrupt the alternator, while leaving the electronics retain their memory setting, by maintaining a connection to the positive terminal from the starter battery.
Is there a technical bulletin on this that I can see for sure, 100% how Mercedes guides this simple, but potentially tricky step?
Ha.
THANK YOU, and THANK YOU!
-Dave
Hello all, I hope you are having a great day so far!
I have a 2009 SL63.
I wish to install a battery tender (CTEK of course!), and I wish to install the semi-permanent eye hook cables, one to the battery, and the negative to the mounting point on the car if possible.
However, I think the electrical system might not like "any old random order", and I know there is a "specific" way, but I am just not sure what it is.
For the record, ha, yes, I did check both the MY09 Owners Manual, as well as the "Maintenance Booklet", but of course, they were of no avail.
I suspect it is this:
TO DISCONNECT:
1. Disconnect negative terminal cable from the starter battery. (leave battery in place.)
2. Disconnect negative terminal cable from the main battery in the trunk.
3. Disconnect positive battery cable from the main battery in the trunk.
TO RECONNECT:
1. Connect positive battery cable to the main battery in the trunk.
2. Connect negative terminal cable to the main battery in the trunk.
3. Connect negative terminal cable to the starter battery.
I understand there is a "special way" to not disrupt the alternator, while leaving the electronics retain their memory setting, by maintaining a connection to the positive terminal from the starter battery.
Is there a technical bulletin on this that I can see for sure, 100% how Mercedes guides this simple, but potentially tricky step?
Ha.
THANK YOU, and THANK YOU!
-Dave
02-02-2019, 11:59 PM
#2
You should not need to disconnect starter battery and it should not need a charger. The accessory battery in trunk is the last battery to connect when replacing both batteries. So just loosen nuts on accessory battery and place ring terminals of CTEK on them accordingly. I just used this process myself and had no issues.
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Gna5ha (09-27-2023)
02-04-2019, 12:45 PM
#3
Member
You should not need to disconnect starter battery and it should not need a charger. The accessory battery in trunk is the last battery to connect when replacing both batteries. So just loosen nuts on accessory battery and place ring terminals of CTEK on them accordingly. I just used this process myself and had no issues.
