Thoughts on AFTERMARKET starter battery?

[wywywywy]

Hi all,

As many of you know, some Mercs (e.g. mid-00s S & SL) have 2 batteries - one for engine starter, one for other things.

The starter battery is a 35ah AGM battery of a proprietary size, so it's only available from Merc for a lot of money (over £200).

However recently I've found that ECP has an aftermarket one made by "LION".

Lion 062 Car Battery (Merc SL Starter)

It's calcium-calcium rather than AGM, and it's much much cheaper.

Is it worth buying? Or is it best to stick with OE?

Thanks.

 

[BlackC55]

Stick with the MB one. Its supposed to have an AGM battery for good reason.

£200 seems a bit steep for a genuine one.

 

[grumpyoldgit]

Not knowing what AGM batteries are, I had to Google it. I assume this it the correct information?
Absorbent Glass Mat (AGM) Battery Information - Battery University

It seems that they are also commonly used in Mobility Scooters and Golf Buggies.
I wonder if these are compatible with cars, assuming they are the correct dimensions?
https://www.google.co.uk/search?q=3...s_sm=122&ie=UTF-8#q=35ah+AGM+battery&tbm=shop

Just a thought!

 

[grober]

http://www.mbclub.co.uk/forums/parts-maintenance-servicing/161488-new-battery-must-purchased-mb.html
Its a height dimension thats critical I believe.

 

[190]

It seems that they are also commonly used in Mobility Scooters and Golf Buggies.
I wonder if these are compatible with cars, assuming they are the correct dimensions?
https://www.google.co.uk/search?q=3...s_sm=122&ie=UTF-8#q=35ah+AGM+battery&tbm=shop

I have such a battery in a motorcycle and even though it was not designed as an automotive starter battery it works just fine. I'd happily try one in a car provided the full specification was available to check it could deliver the starting amps needed. Most generic AGM's will because they have a very low internal resistance compared to standard wet cell batteries. Whether they last is the question and as I'm only 2 years in I can't answer that.

As for substituting a wet cell battery in place of an AGM I wouldn't do it. AGM 's generally require a higher charging voltage so if the cars charging system is set up for an AGM it might be too much for a wet cell. I've never owned a car with 2 batteries but I would imagine that unless the charging system is very smart it would be inappropriate to have a mix of batteries with different chemistry/construction a they have different operating voltages and charging requirements. I know that with some recent BMW's you have to tell the car what battery you have fitted so it uses the correct setting.

 

[andy27168]

Hi,
I think you have been quoted the wrong price for the smaller battery I just bought one for my CLS55, that was about £70 IIRC from MB. I think they have quoted you for the larger boot mounted battery, which in the case of the CLS is no longer and AGM battery but a normal lead acid, and was £125-135 from MB.
I believe the unit which controls the way the car charges the two batteries is subject to updates from MB and if it is up to date software wise then the battery should be what MB recommend as has been touched upon the charging characteristics of a lead acid and an AGM battery are different.
The smaller battery I don't believe there is an exact cross over to an aftermarket one there is always one dimension that is wrong, for the amount of savings to be made I decided that only an MB one would do.

 

[Auto-mobile]

Cls battery is the same as a w211 smaller, w221 starter battery (lion branded in the link above) is twice the size.

I have fitted the lion battery to a s500 (customer request) been a year without problems so far.