CLS Auxiliary Battery

[Dord1954]

Hi I recently had the red 'battery' symbol appear on screen on my 2006 CLS320 CDI with message to visit workshop, well I did a volt test on main battery with ignition off it is 11.9 volts and with engine running 14+ volts. a test on the auxiliary (once I discovered that there was such a thing) showed less than 10 volts. I am going to replace the auxiliary battery and wondered if anybody has used a motorcycle battery instead of OE and if so how did it work out, also would a 'gel' battery be as good
thanks

 

[AMGeed]

I believe the OE aux battery is lead acid. Costs around £75 from the main dealer.
It is the same battery as a motorcycle one, but I'd check the output of the one you have and replace with the same.
ECP do a cheapie Lion brand if you are looking to save £25

 

[Dord1954]

ECP quoted over £80 but I wondered if a motorcycle battery would suffice at less than half the price and unfortunately I have been unemployed for a while with not much prospect of work at 63 so every penny counts at the minute

 

[AMGeed]

^Understood. Good luck with the job search.
Just ensure the same spec for the replacement.
I would buy OE with a good MB guarantee.

 

[Dord1954]

just looked on mb teeside ebay account and they do them for £65 delivered, so thats the one for me lol

 

[190]

Depends how much the motorcyle battery is but I'd consider one if it matched the specifications of the OEM item

Whether standard wet cell , AGM or Gel, they are all Lead acid batteries, only the construction differs and the maximum safe charging voltage. If the existing one is an AGM then replace it with an AGM. You would have to be very careful replacing an AGM with a Gel as they are more sensitive to overcharging and can't cope with the high charge voltages that an AGM can.

 

[Dord1954]

Lucas sell a battery, model LYTX14BS and advertise it as a replacement for the model number that is on my car but it is an AGM and only £40 so now Im wondering if its suitable. How do I tell if mine is AGM? I doubt it is as it looks very old

 

[AMGeed]

If its an AGM it will be printed somewhere on front the battery. OE are ordinary lead acid, at least mine was.

 

[Dord1954]

just read 190s post again and its the gel types that could have trouble coping with voltage not the AGM

 

[grober]

Genuine Mercedes-Benz E-Class - Auxiliary Battery 12V 12AH A2115410001 | eBay

 

[andy27168]

Hi,
Aux battery on a 211/219 - AGM - 12V, 12Ah, 170 A.

 

[190]

Now we know the battery is a 12 AH I'm with the original poster in thinking £80 is expensive for the battery of that size. Even at £65 it's more than you would pay for a motorcycle battery. I pay approx £42 for a larger 18 AH AGM batter on my motorcycle.

As to what type the OP's original battery is you can get a clue by measuring the fully charged rested voltage. Fully charge the battery then leave it to rest overnight. Measure the battery voltage. If it's 12.6 -12.7 volts it's a normal flooded wet cell. If it's 12.8 - 13.0 volts it will be an AGM

 

[Dord1954]

I have removed the old battery and will be charging in a little while to see the voltage but at the moment it is only showing 11.3 volts after just being out for a run and showing 14+ volts when the engine is running so my guess is that its failing

 

[Dord1954]

my 'smart' battery charger told me that the aux battery is indeed caput so a new one tomorrow hopefully will sort the problem, does anybody know if the red battery warning on the clock will reset itself?

 

[Petrol Pete]

Go online to Tayna batteries, look for a discount code. I have had many batteries from them for all kinds of things. Without incident and always a good price.

 

[b1g1an]

I used a Yuasa YTX14-BS, top quality bike battery to same spec as MB one and £40 delivered if you shop around.

 

[Dord1954]

Well a local agricultural merchant had a Lucas LYTX 14 BS battery that is the same spec as the Mercedes battery for £34.20 inc vat. it is an AGM battery and sounded just the job. I rang Manbat, who now own the rights to Lucas batteries, and a very honest sounding guy the told me that although the battery would indeed do the job he would not recommend that I use one for an auxiliary battery as he had heard of problems with electrical items arising that could possibly be due to the non OE battery being used.
so now Im back to square one and thinking I will get a merc one

 

[Dord1954]

I used a Yuasa YTX14-BS, top quality bike battery to same spec as MB one and £40 delivered if you shop around.

Hi is this on a CLS? not that that should make a difference, how long have you been using it and have you had any issues at all?

 

[55AMGsuperchare]

Well a local agricultural merchant had a Lucas LYTX 14 BS battery that is the same spec as the Mercedes battery for £34.20 inc vat. it is an AGM battery and sounded just the job. I rang Manbat, who now own the rights to Lucas batteries, and a very honest sounding guy the told me that although the battery would indeed do the job he would not recommend that I use one for an auxiliary battery as he had heard of problems with electrical items arising that could possibly be due to the non OE battery being used.
so now Im back to square one and thinking I will get a merc one

Im a electrical engineer and looking at the specs of the LYTX 14 battery I see no reason why it would not work. I think Il buy one and try it out.

 

[Dord1954]

thats what I thought but is it worth the chance of causing more trouble, although I cant for the life of me think what could go wrong, and I have now found an OE one for £64 so is it worth the risk. just sticks in my craw paying double for the same thing lol