AGM Battery Faulty -

[rorywquin]

Low and slow, just like a boeuf bourguignon. AGM batteries don't respond well to a fast charger. I'm speculating here, but that may have been your problem.

How quickly do alternators charge batteries ?

 

[ecoman]

How quickly do alternators charge batteries ?

a good point Rory- all I know is my bench charger outputs way less than the alternator. then again, I'm unsure of what's left after powering all of the E-Class circuits especially this time of year.

I may have to simply eat the £120 charge which wipes out the bargain battery they sold me 9 months ago for £124 :-(

 

[ecoman]

just found datasheet for the charger and it says:

'Recharging of all type of lead acid batteries including gel, wet and agm'

 

[Uncle Benz]

How quickly do alternators charge batteries ?

Smart charge, computer controlled alternators on cars now. A few cars need the car programming to accept the new battery and reset the charging parameters.

 

[malcolm E53 AMG]

Just finished charging my 212 AGM battery as the car hasn’t been used much over the last couple of months and was labouring to start on a cold morning. Using a CTEK MSX 5.0 (showing a low charge of 3/6 lamps) it took 7 hours to register a full charge. At 7+ years old I’ll probably change the starter and auxiliary battery this year when it warms up a bit

 

[ecoman]

A quick update....

So it turns out MB use a CTEK charger (couldn't get the model) which put enough charge into the battery over 2 hours for their test equipment to register a pass. Unusually the MB kit did not show the true CCA or AH readings, only those entered by the tech. The the printout from when they 1st connected showed 7.2v and CCA 850 , 92Ah. MB Technical note 319 HO Dual Battery shows the printout from the Midtronics 717 which displays the actual CCA and Ah readings of the battery- it also says a difference of 10% from specification should be replaced, so I guess I'll need those figures.

They did split the bill, but it's still an expensive battery charge, (though they did valet the car!) Will now take this up with the roadside recovery for their readings as it was that diagnosis that lead me to return it to MB. Will also check the battery and get a second opinion on its condition before going back to Mercedes.

 

[rorywquin]

Smart charge, computer controlled alternators on cars now. A few cars need the car programming to accept the new battery and reset the charging parameters.

I always thought that it was a pretty quick charge from an alternator - cold morning lots of amps needed to start up and then have to put it back in the battery before it is needed again.

I did a trip across the Simpson desert (Australia) and two of us got our alternators clogged with mud - so no charging of batteries (yes first rains in almost 20 years)> There were 4 Landcruisers of which, two were identical - we'd swap batteries back and forth between them (one getting run down and the other getting charged) and I seem to recall that we swapped them 2 or three times a day (so a full charge from flat in about 4 hours???).

I had a triple battery setup and was able to run during the day and charge at night with my Honda generator and faithful Ctek and just managed to get through the 2 days that I had no alternator.