AGM Battery charging

rafletcher

Registered User
After several weeks of occasional short journeys during which the stop/start function didn’t, today I took the car out for the best part of an hour up and down the local bypass, as well as visits to 2 local towns. The battery still isn’t sufficiently charged for the stop/start to operate. I’m not bothered by the lack of the feature, I usually turn it off, but I don’t want to be shelling out for a new battery, which is at least £250. How much does it take to get it back up and running?
 

NevMan

Well known member
After several weeks of occasional short journeys during which the stop/start function didn’t, today I took the car out for the best part of an hour up and down the local bypass, as well as visits to 2 local towns. The battery still isn’t sufficiently charged for the stop/start to operate. I’m not bothered by the lack of the feature, I usually turn it off, but I don’t want to be shelling out for a new battery, which is at least £250. How much does it take to get it back up and running?

Why don’t you spend some money on a trickle charger like a CTEK MXS-5.0. Deals with normal and AGM batteries
 

CHEZ

moderately amusing
Supporter
Or £24 on a maypole charger that does exactly the same as a CTEK.?
And keep your AGM battery in perfect condition.
 
I'm not sure I'd worry about it over much provided you're not getting any low battery warnings and it fires up okay, especially as you don't use the start/stop feature anyway.

The start/stop in my car - a three and a half year-old 2.0 TFSI 190 - has hardly ever worked unless I've driven well over a hundred miles, yet in all that time I've only ever had one low battery warning, and it's never once failed to burst into life. There's nothing wrong with the start/stop; it's just that there isn't enough juice in the battery for it to work most of the time.

Am I bothered?

Nope.

Start/stop is a pain in the rectum anyway.

And this battery is one of those Moll EFB jobs which are spoken of so very highly on here, so it isn't even a decent AGM.

I do hook it up to a CTEK from time to time when I remember, but it never takes more than two or three hours to light up fully-charged.

It may well be that I'm constantly walking the tightrope of being stuck in the middle of nowhere with nothing but the dull click of a starter solenoid for company, but like all adrenaline junkies I live my life right on the ragged edge.

:racer:

.
 
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eribaMotters

Registered User
I'd like to know the best route forward for when the battery fails as I'm led to believe with stop-start technolgy they do not last so long.
Is it best to buy a good quality battery and take it to your local indi garage who you pay to install as the ecu needs to be told a new battery has been fitted. If so what are the typical costs.

Colin
 

rafletcher

Registered User
I do have a “smart” charger as it happens, but it’s a pain to use it because of parking where I live.


A secondary question, as it’s been sooooo long since I charged a battery - where should I hook the charger up to?
 

CHEZ

moderately amusing
Supporter
I do have a “smart” charger as it happens, but it’s a pain to use it because of parking where I live.


A secondary question, as it’s been sooooo long since I charged a battery - where should I hook the charger up to?

Ah that old chestnut.
Earth it first to the chassis or strut top, then to positive terminal on battery.
 

rafletcher

Registered User
Ta. I would have checked the handbook, except the dealer - who was most particular my trade-in had all its paperwork - appears to have lost mine, and being closed since a week after I got the car I’ve not had much luck in getting a set.
 

eribaMotters

Registered User
I've a digital copy of the owners manual. I cannot remember how I got it as Audi do not make available digitally. As it is over 2mb I cannot attach it to a post. If you PM me your e-mail I can send it to you.

Colin
 
Ah that old chestnut.
Earth it first to the chassis or strut top, then to positive terminal on battery.
Other way round.

Connect the positive terminal first. When you're done, disconnect the negative (the bulkhead/chassis tab in this case) first.

Same as when connecting the battery to (or disconnecting the battery from) the car.

It's not quite as important when you're hooking up a charger - assuming it's off at the mains when you do - but there's much less chance of a spark from an accidental short to ground this way.



.
 
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Flowrider99

Registered User
Ah that old chestnut.
Earth it first to the chassis or strut top, then to positive terminal on battery.
Positive first not negative.
 
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