I’ve often wondered why Lenny hates AGM batteries? (1 Viewer)

[Speve]

Hi everyone I came across a little info today whilst researching how to install Lithium on my B678DL.
First checking the equipment I have always had to charge my two 95a AGMs I came accros this schaudt auxiliary 18amp charger LAS 1218 BUS. I was interested to find out that it actually doubles the charge of the EBL 30 and is specifically used when an extra leisure battery has been requested? Thus helping lengthen the life of AGM batteries.Thats probably the reason my batteries have lasted as long as they have at over Five years old still going well.
here is a quote from an old forum back in 2016 from Aa batteries Which Lenny HB replied?
which may be useful to those who have AGMs and don’t have this extra charger.

AGM1 and AGM2 optimised Schaudt auxiliary charger, the LAS 1218 BUS. The charger works alongside the existing Schaudt Electroblocks, like the EBL 99, EBL101, EBL 220, etc to faster charge AGM batteries and help prolong their life by use of the correct charging voltage/profile.

We do still do not recommend the fitment of AGM batteries in a Motorhome. However, where you have AGM batteries fitted already and are seeing shorter than expected lifetime plus a lower charge state, these units will help

 

[Jim]

I bought a set of AGMs and a charger with a proper AGM profile. They lasted less than a year, so there was something about my van they did not like.

 

[Speve]

I bought a set of AGMs and a charger with a proper AGM profile. They lasted less than a year, so there was something about my van they did not like.

Hi Jim yet we have had them in our last three Motorhomes and never had problems I wouldn’t say we are using them as Lenny HB does off grid as we do use EHU occasionally.
So they are not hammered quite so much.

 

[Lenny HB]

I would have given your post a like but a post liking AGM, no, can't bring myself to do that.

It's not just me loads of people and quite a few on this forum have had problems with them.
One couple bought some expensive professional AGM's saw them at a rally a couple of years ago and asked how they were going, the answer I got "I wish we had listened to you".

Manufacturers get away with fitting crap batteries because a high percentage of their customers use EHU, (something we don't do) so they would never know that the batteries capacity was reduced considerably.
A few people on the forum have said how good their AGM's are and I've asked them to run a capacity test, I wonder why no one has ever come back with the results.

 

[Lenny HB]

Speve come on then Alan run a capacity test and tell me how well they are performing.

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[VXman]

Mine are doing well. 2 years 3 months and 22000 miles, (4 months travelling a year) mostly off grid.

 

[Gromett]

I had AGMs for years. 1000AH battery bank using Victrons. After 4 years 2 of which were fulltiming I sold 2 of them and retained 2. These lasted a further 4 years of fulltiming so a total of 8 years.

 

[Speve]

Speve come on then Alan run a capacity test and tell me how well they are performing.

Absolutely no offence meant to you Lenny and I understand why you are so anti AGM . I will do a capacity test when I install my new system in a week or two mainly to find out how they are this far along? They are coming up six years old and as I said earlier they probably haven't had the hammering that you would give them wilding.
my point being that if you are only using them moderately they can work for you with that extra charger that none of the dealers tell you about Incidentally I would not have known if I had not been researching Lithiums which are an expensive replacement which some would not want or can not afford

 

[Pausim]

Alpha Batteries have produced a guide to AGM batteries

A Detailed Guide to AGM Batteries - Alpha Batteries

With AGM products becoming more widespread in their use, knowing when you can or should use one and how to look after it properly is all the more important - our guide is here to help.

www.alpha-batteries.co.uk

My take on their article is that AGM batteries can last but they have to be treated exactly right because they are very fussy about being charged correctly. They pick out a number of particular problems they have come across. One is mains charging by standard chargers that are simply not suitable despite manufacturers statements suggesting they are, Sargent get a specific mention for this failing . Another area is split chargers which are unlikely to achieve sufficient voltage to charge AGM properly. They also mention specific AGM profiles that have equalisation phases that exceed a damaging 15V.

Basically for AGM 14.4V is not enough, 14.6-14.8V is correct and 15V is too much. Then of course they also need the right length of time on charge because too little or too much time is bad for them.

Basically I am in the camp that avoids AGM leisure batteries but it seems they can last if you get everything spot on.

 

[emjaiuk]

I’ve often wondered why Lenny hates AGM batteries?​

In a word, Banner

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[Lenny HB]

Mine are doing well. 2 years 3 months and 22000 miles, (4 months travelling a year) mostly off grid.

Give us an update in 5 years, 2 of my Gels are over 7 years old and one is 6 years old all performing like new apart from age related losses, AGM's were dearer than Gels so I would expect them to last longer.

 

[tony_g]

"We do still do not recommend the fitment of AGM batteries in a Motorhome. However, where you have AGM batteries fitted already and are seeing shorter than expected lifetime plus a lower charge state, these units will help"

Is that a quote from Schaudt? My Hymer came supplied with an AGM and I added a second, bowing to the inevitable. However, performance steeply declined in a couple of years. The replacement gels are far superior imho.

 

[Speve]

Is that a quote from Schaudt? My Hymer came supplied with an AGM and I added a second, bowing to the inevitable. However, performance steeply declined in a couple of years. The replacement gels are far superior imho.

No it’s from a post in a 2016 thread by Aa batteries.

 

[POH]

Can you just drop a gel battery in place of agm's just thinking ahead as mine are coming up to 3years old , friend has just had to replace his in France they were about 4yrs old and then found it won't charge , I don't want to go down that road hence asking if it's possible.

 

[Lenny HB]

Can you just drop a gel battery in place of agm's just thinking ahead as mine are coming up to 3years old , friend has just had to replace his in France they were about 4yrs old and then found it won't charge , I don't want to go down that road hence asking if it's possible.

You need chargers with a Gel profile.
Gels charge at lower voltage than AGM's and need a long absorbtion charge.

What chargers do you have?

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[POH]

You need chargers with a Gel profile.
Gels charge at lower voltage than AGM's and need a long absorbtion charge.

What chargers do you have?

Not sure Lenny I will check in the next few days and get back , m/h is a pilote 740 evidence 21 plate, maybe someone might know sooner than I can check

 

[Lenny HB]

Not sure Lenny I will check in the next few days and get back , m/h is a pilote 740 evidence 21 plate, maybe someone might know sooner than I can check

Probably has a CBE unit that should have a Gel option and so should your B2B need to look at solar as well

 

[Captain Yoghurtpot]

Another interesting Battery thread with aspects regarding suitability in a Motorhome I knew nothing about.
Am currently on the lookout for a new leisure battery for very limited off- grid use as EHU is our bag mainly, and our van is a year 2000 with the subsequent wiring and chargers of that ilk, so for me , its most likely going to be good old fashioned Lead Acid, as I definitely know that will most certainly just " drop in".

 

[POH]

Probably has a CBE unit that should have a Gel option and so should your B2B need to look at solar as well

Got solar panel think it's a 100w / 120w one don't think I have b2b .

 

[VXman]

Give us an update in 5 years, 2 of my Gels are over 7 years old and one is 6 years old all performing like new apart from age related losses, AGM's were dearer than Gels so I would expect them to last longer.

Will do, but to be honest if a battery lasts for 5 years then I'm reasonably happy. That's generally what they are warrantied for. I'm not sure the price is to make them last longer, just that they charge quicker.

On a different tack. My 2010 Renault Megane battery is still original. It had 3 years of non use while I was working abroad but a quick charge on return and it's been fine since. It can last 2 weeks in a airport carpark (alarm and electronic locking active). It won't crank for an extended time but generally starts on first click so it's not a problem. There is a lot to be said for old fashioned lead acid!

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[Lenny HB]

On a different tack. My 2010 Renault Megane battery is still original. It had 3 years of non use while I was working abroad but a quick charge on return and it's been fine since. It can last 2 weeks in a airport carpark (alarm and electronic locking active)

Had my car 11 years still on original battery car starts first turn after leaving it for over 6 weeks. Hate to admit it, it's an AGM I reckon it's fluke, still wouldn't use one leisure use.

 

[Hoovie]

I would have given your post a like but a post liking AGM, no, can't bring myself to do that.

It's not just me loads of people and quite a few on this forum have had problems with them.
One couple bought some expensive professional AGM's saw them at a rally a couple of years ago and asked how they were going, the answer I got "I wish we had listened to you".

Manufacturers get away with fitting crap batteries because a high percentage of their customers use EHU, (something we don't do) so they would never know that the batteries capacity was reduced considerably.

A few people on the forum have said how good their AGM's are and I've asked them to run a capacity test, I wonder why no one has ever come back with the results.

I used to as a matter of course every 6 months break the parallel battery bank and test each battery individually to check all were performing as they should and equally, including a logged discharge to 50%
Didn't have any issues from 1 bank of 4 x 100Ah AGMs and later on 1 bank of 3 x 210Ah Lead Carbon AGMs.

 

[chaser]

Couldn't be bothered to read all the posts but have 2 agms with an old charger out of a caravan and two 100 w solar panels and a Chinese controller and they still register as good as they were three years ago.

 

[Lenny HB]

Couldn't be bothered to read all the posts but have 2 agms with an old charger out of a caravan and two 100 w solar panels and a Chinese controller and they still register as good as they were three years ago.

I bet the capacity is well down

 

[chaser]

I bet the capacity is well down

No idea but never seen them below 12. 5 even with running a compressor fridge and everything else. Will be up to 14 by 11 o clock everyday, no hookup.

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[bigtwin]

Will be up to 14 by 11 o clock everyday

That’s the solar voltage and not the inherent battery voltage.

Ian

 

[headlight]

No idea but never seen them below 12. 5 even with running a compressor fridge and everything else. Will be up to 14 by 11 o clock everyday, no hookup.

Voltage and capacity are different.
You can have a battery showing good voltage but have poor capacity.
BTW I'm not knocking AGM's as I've never had them.

 

[chaser]

Voltage and capacity are different.
You can have a battery showing good voltage but have poor capacity.
BTW I'm not knocking AGM's as I've never had them.

I know all about these different figures but if everything keeps working what else can we do?

 

[ChrisL]

I was under the impression that AGM batteries were developed to deal with stop start motoring, where the engine stops when the car stops and starts again when you press the accelerator, the battery needs to recharge quickly to cope with the rapid cycling charge/discharge and the lower internal resistance facilitates this, I don't think they were ever intended for leisure battery use but were hyped as the latest and greatest battery technology when they first became available and consequently were being used for something they weren't intended for.

 

[Hoovie]

I was under the impression that AGM batteries were developed to deal with stop start motoring, where the engine stops when the car stops and starts again when you press the accelerator, the battery needs to recharge quickly to cope with the rapid cycling charge/discharge and the lower internal resistance facilitates this, I don't think they were ever intended for leisure battery use but were hyped as the latest and greatest battery technology when they first became available and consequently were being used for something they weren't intended for.

AGM batteries were, I am sure, around a lot earlier than stop-start vehicles. They have been used as Leisure Batteries longer than stop-start vehicles as well I have no doubt and are perfectly fine for that purpose.

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