AGM Engine Battery in 2014 Hymer

[John H.]

After having had the dreaded Air Bag Failure on our 2014 Hynmer and being told to fully charge the battery before re-fitting the control unit, I replaced the engine battery with a new AGM battery from Halfords.

I have also fiited Lithium leisure batteries with a Sterling B2B charger.

Since then, the Air Bag ECU has failed twice more.

Is my problem more likely to be caused by the B2B charger or the AGM battery?

 

[Googlebot]

Neither should cause that failure.

Do you let your engine battery run low a lot?

 

[John H.]

No. (at least, not knowingly)

I have now got a new Air Bag ECU (manufactured April this year) which I am having aligned for the Hymer today. Hopefully, that wil solve the problem.

 

[Lenny HB]

AGM batteries can be very unreliable you need to monitor the voltage carefully.
If it was me I would change it for a decent standard battery, your vehicle is not designed for AGM so it will probably never get a full charge from the alternator AGM's need a higher charge voltage.
I just replaced my cab battery with a Yuasa 5000 with a 5 year warranty £105 from Halfords.

 

[John H.]

Neither should cause that failure.

your vehicle is not designed for AGM so it will probably never get a full charge from the alternator

So. I am willing to take more advice. Do I need to swap out my nice new AGM engine battery, or not.
I am inclined to think - Yes. But I would like to avoid another expense.

I now have a nice brannd new Air Bag ECU coded up for my Hymer, but I am reluctant to put it in if it is likely to fail like the old one because the AGM battery is not fully charged.

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[Googlebot]

I wouldn’t chance it to be honest. I would keep the AGM spare or sell on eBay or here and recoup some of the cost.

If you are having frequent issues though, it might work out cheaper to get an auto electrician in to check everything. A dodgy earth or connection could cause spikes that will kill the airbag ECU.

 

[TheBig1]

would you mind explaining the rationale for changing the engine battery for AGM? The charging system in your van is not correct to use AGM as an engine battery

 

[Lenny HB]

I would be inclined to monitor the battery voltage for a couple of weeks see how it's performing. If any doubts change it before fitting the new ECU.

 

[John H.]

The rationale was simply to replace the engine battery with a new one. AGM just seemed like a good idea at the time because the original leisure battery was AGM.

I am learning. . . . Slowly!

 

[Lenny HB]

The rationale was simply to replace the engine battery with a new one. AGM just seemed like a good idea at the time because the original leisure battery was AGM.

I am learning. . . . Slowly!

AGM are pretty useless as leisure batteries and best avoided. Replaced the AGM in my Hymer got the dealer to swap the AGM for the Gels in my last van when we picked it up. Last van originally had AGM they lasted 18 months.

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[John H.]

your vehicle is not designed for AGM so it will probably never get a full charge from the alternator AGM's need a higher charge voltage.
I just replaced my cab battery with a Yuasa 5000 with a 5 year warranty £105 from Halfords.

I have taken your advice and fitted a Yuasa 5000 from Halfords,

The new Air Bag ECU now seems OK. Only driven 20 miles but all good so far.

 

[Pugsy]

AGM batteries can be very unreliable you need to monitor the voltage carefully.
If it was me I would change it for a decent standard battery, your vehicle is not designed for AGM so it will probably never get a full charge from the alternator AGM's need a higher charge voltage.
I just replaced my cab battery with a Yuasa 5000 with a 5 year warranty £105 from Halfords.

Which battery model did you pick Lenny HB ,i looked at Halfords and there is a few 5000, trying to help a neighbour choose a battery for his caravan he is fitting a 100w solar panel.
cheers Cris.
He was going to fit an agm,i told him no, i am away in the van up in Aberfoyle and he keeps sending me all these questions and ebay links .
Ps ,sorry being a dummy, trying to look on my mobile whilst out on bike and did not click to the ah number Doh!!!

 

[Pugsy]

Which battery model did you pick Lenny HB ,i looked at Halfords and there is a few 5000, trying to help a neighbour choose a battery for his caravan he is fitting a 100w solar panel.
cheers Cris.
He was going to fit an agm,i told him no, i am away in the van up in Aberfoyle and he keeps sending me all these questions and ebay links .
Ps ,sorry being a dummy, trying to look on my mobile whilst out on bike and did not click to the ah number Doh!!!

Hi Lenny HB , thanks anyway he is getting the battery from Alpha-batteries, i think ,i hope, i might get a beer in peace tonight, .

Cheers Cris.

 

[Emmit]

AGM are pretty useless as leisure batteries and best avoided. Replaced the AGM in my Hymer got the dealer to swap the AGM for the Gels in my last van when we picked it up. Last van originally had AGM they lasted 18 months.

I'm not going to get into an argument with you But;
With respect, you should preface your comments above with, "In my opinion".
As an alternative, I can say that the AGM's in my recently sold last van were a good three years old when we changed and they were still going strong.
We were told by an expert that, providing that the battery charger was able to be adjusted to allow for the higher charge needed for the AGM's (and was so adjusted) then we should not encounter any problems, and that's what happened. We did not encounter any problems.

 

[Lenny HB]

I'm not going to get into an argument with you But;
With respect, you should preface your comments above with, "In my opinion".
As an alternative, I can say that the AGM's in my recently sold last van were a good three years old when we changed and they were still going strong.
We were told by an expert that, providing that the battery charger was able to be adjusted to allow for the higher charge needed for the AGM's (and was so adjusted) then we should not encounter any problems, and that's what happened. We did not encounter any problems.

Even our leader Jim thinks the same as me. OK some people have had them last and they are not so much a problem if you use EHU (we don't). You have only have to look on the German forums to see all the problems with them. They are just not worth risking your hard earned cash on.

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