trickle charging battery - CTEK 5.0

[Tinker15]

OP - Did you consult with CTEK about reconditioning an AGM? All the documentation (included what you've quoted in your original post) that I've read said that RECOND mode should only be used on "wet" or "flooded" batteries. It also mentioned water loss when RECOND is used. Is the Gel in AGM considered "wet"? There is no water in an AGM. Most AGM that I have came across does not like to see a charging voltage above 14.4V, so how safe is it to recondition it at 15.7V?

I don’t know about the USA but in the UK AGM batteries are not considered Gel Cell batteries and will be OK on a CTEK.

 

[Tinker15]

I’ve had the car for almost 4 years, and not replaced it. So older than that!

Is the alternator working?

 

[samZ4M]

Yes, it outputs 14.4v from alternator to ground.

 

[Tinker15]

Seems strange that it went from 3 to 7 in 4 hours if it was so flat. If you have a local battery supplier (Halfords?) you could ask them to test the battery. If it is buggered I bought a Varta AGM through Tanya Batteries on eBay. It was delivered next day at a reasonable cost.

 

[samZ4M]

ECP have a Bosch AGM for £165 delivered. Same AH as the one you posted. I always thought they'd be £350.

Do they need coding to the car?

Are we ruling out it being a drain somewhere? I've never had a drain issue before, nothings been changed/fitted recently either. It's just been off the road for 3 months.

 

[Tinker15]

Both Bosch and Varta batteries are made by Johnson Control so there is no difference really. It needed coding on my E89 which my local independent did for me. I don’t know about E85/E86. It could be a drain but they are not easy to find.

 

[samZ4M]

I'm going to give it one last chance, leaving the battery charger of for a full week and see where we are. Ideally, I just want to trickle it once a month or so, as in summer, I'll use it for commuting sometimes.

If it's still playing up, I'll spring for a new battery.

A mate has given me an Bosch S4, which I'll keep in the car (as a spare) for the time being, in case I'm stranded with no one to help jump it. i don't think it'd fit in the housing, otherwise I'd be temped to fit it.

 

[Tinker15]

Good luck!

 

[XMetal]

I don’t know about the USA but in the UK AGM batteries are not considered Gel Cell batteries and will be OK on a CTEK.

Regardless whether AGM batteries are considered Gel Cell or not, my concern was whether the RECOND mode was safe for AGM charging at 15.7V. CTEK is fine on all batteries when used properly.

OP, if the battery is older than 4 years, why are you still messing with it and risk being stranded? Even if it's tested good, an older battery can still fail without warning. To me, Batteries are considered 4 - 5 years routine maintenance items and get swap out regardless.

 

[samZ4M]

Because I generally drive it to a point, such as a friends house. So will always be able to jump it. Why not give it 1 more chance?

 

[samZ4M]

I took the Z to work on Friday, disconnected the charger, battery indicator was flashing green, went no problem. Drove it home again, started first time.

Went to use it Sun, light flashing orange, but it did start. Reading into it, we don't know the threshold, so is the green light only for 100%, so orange is fine? That'd not be a good indicator for me...

I'm going to leave it off, and see what it's like Fri (soonest I'll probably drive it). Maybe take some readings from the batt to see if it's not holding charge.

Next annoyance will be finding out if it's a drain or crap battery. I really don't want to spring for a new battery if something is causing a drain. Maybe I'll keep my eyes peeled for a good ECP code or similar and go with it.