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AGM batteries & EBL30 - winter maintenance


roger20

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I would appreciate some advice on what is bestpractice to maintain twin Varta AGM batteries (LA95) over winter. Our Hymer hasa Schaudt EBL30 with an additional charger for the second battery.

To avoid overcharging I wondered whetherdisconnecting the leisure batteries using the panel slider, as suggested in theEBL30 manual (attached) seemed a good idea. I can then continuously monitortheir voltage with an external display and reconnect when the voltage falls tosay 12.75v which one chart I have seen suggests will still be around 90%.

 This willleave the lead acid vehicle battery being continuously charged at around 13.7vbut at least this can be topped up should electrolyte levels eventually fall.

The EBL30 gives a main charge for 4 hoursat 14.7v dropping after to 13.7v and one suggestion I read was that it mightonly need 15 minutes at the main charge rate to maintain the batteries at anoptimum level. One of the (few!) advantages of an AGM seems to be a low self-dischargerate of 1-2%/month, especially in colder weather so perhaps a brief top-upmight be sufficient. At the moment, when not being charged I assume that thegradual discharge shown on the leisure batteries is because all three batteriesare linked.  

As an alternative I could use a timer controlled charge once or twice aweek but this would presumably need a minimum of 4 hours each time. Does repetitivecharging at initial high voltages result in internal gassing off whicheventually leads to an irreplaceable loss of electrolyte in a sealed AGMbattery? Leaving all the batteries connected presumably means their dischargewill be much greater than having the AGMs disconnected, therefore needing moreregular charging.

At the moment, now on float charge, the voltage display is showing14.04v instead of 13.7v. Could this be intelligent charging compensating thefloat voltage at a higher level because of the colder temperatures - it's 9degrees at the moment?

 

     

 

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"To avoid overcharging I wondered whether disconnecting the leisure batteries using the panel slider, as suggested in the EBL30 manual (attached) seemed a good idea. I can then continuously monitor their voltage with an external display and reconnect when the voltage falls to say 12.75v which one chart I have seen suggests will still be around 90%.

 

This will leave the lead acid vehicle battery being continuously charged at around 13.7v but at least this can be topped up should electrolyte levels eventually fall.

 

The EBL30 gives a main charge for 4 hours at 14.7v dropping after to 13.7v and one suggestion I read was that it might only need 15 minutes at the main charge rate to maintain the batteries at an optimum level. One of the (few!) advantages of an AGM seems to be a low self-discharge rate of 1-2%/month, especially in colder weather so perhaps a brief top-up might be sufficient. At the moment, when not being charged I assume that the gradual discharge shown on the leisure batteries is because all three batteries are linked.

 

As an alternative I could use a timer controlled charge once or twice a week but this would presumably need a minimum of 4 hours each time. Does repetitive charging at initial high voltages result in internal gassing off which eventually leads to an irreplaceable loss of electrolyte in a sealed AGMbattery? Leaving all the batteries connected presumably means their discharge will be much greater than having the AGMs disconnected, therefore needing more regular charging.

 

At the moment, now on float charge, the voltage display is showing 14.04v instead of 13.7v. Could this be intelligent charging compensating the float voltage at a higher level because of the colder temperatures - it's 9degrees at the moment?"

 

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Firstly the 'slide battery isolation' switch does not isolate the batteries from the EBL. All it does is isolate the 'consumers' from the EBL, the batteries remain connected to the EBL at all times and will be charged by either, or both, chargers regardless of the slide switch position. There is an issue with German to English translation in the manual.

 

Secondly, All three batteries are not linked together. The EBL will treat the Starter battery as a 'separate battery bank' supplying it with a lower voltage and current (sometimes as low as 2 amps on some EBL's) to the main Habitation area battery.

 

 

Charging on a 'timer' is probably the best option, but not every week. Good batteries will stay charged for about 4 weeks but obviously that will depend on Alarm, radio, etc power draw, so work out the best timer interval that suits your vehicle.

When it gets below 12.75v then give it a boost for about 8 hours.

Suggest you unplug the Aux charger from it's mains supply during periods of 'Lay up' and plug it back in when you need full 36amps charge rate?

 

 

I don't understand why you have a 14.04v charge rate at the present time as the EBL's do not have any form of temperature compensation?

Are you sure the AGM batteries are still ok or maybe you have a Solar Panel?

 

 

 

 

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We have a single Banner AGM leisure battery, it has never given me any concern due to discharging in storage, as Alan advises once a week is not needed. The vehicle battery however is a different matter, left to it's own devises it will discharge in a couple of weeks, my answer to this was a 40w solar panel clipped to the vehicle battery, although this is on quite a long cable so is not running at peak performance.

 

After 7 years of this both batteries are showing signs of being past there best and are soon to be replaced.

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roger20 - 2018-10-30 9:46 PM

 

It was set to yes - what should it be? Having trouble even now getting the cursor to enter the dialogue box and had to right click to get going for some reason 

 

Sorry for the Off Topic posts, mine has always been set to No.

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This is a very interesting thread for me as I'm currently looking at the Hymercar Pop-top range of vans and they all seem to be equipped with an EBL30 and twin AGM Varta batteries.

 

Alan - The Hymercar in question (my preferred choice) has not been driven in several months and with no EHU supply either so the batteries are now resting at 11.3 to 11.5v.

 

I suspect the Varta batteries will be shot by now so in your opinion which battery type and regulator would you recommend for an EBL30.

 

Regards,

 

Andrew

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Keithl - 2018-10-31 7:09 AM

 

roger20 - 2018-10-30 9:46 PM

 

It was set to yes - what should it be? Having trouble even now getting the cursor to enter the dialogue box and had to right click to get going for some reason 

 

Sorry for the Off Topic posts, mine has always been set to No.

 

Information about the forum Profile can be found here

 

https://forums.outandaboutlive.co.uk/forums/Code-of-Conduct-and-User-Guidelines/Forum-User-Guide/You-and-your-profile/3990/

 

Advice on ‘rich edit’ is as follows:

 

"Use rich edit box when composing messages: Set to ‘NO' by default. Selecting ‘YES' will display a more advanced entry form when you post a reply or start a new thread - it's a bit like a word processor and some people may find it easier to use.”

 

The ‘rich edit’ option does not work properly for me (probably because I’m a Mac user) and it’s a real pain if I want to cut-and-shut when quoting entries by forum-members who have the option set to “YES” in their Profile.

 

If you know what you are doing, have deliberately chosen the “YES” setting and find ‘rich edit’ beneficial, stay with that setting. But otherwise, I strongly encourage everybody who has the option set to “YES” in their Profile to change it to “NO”.

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Bop - 2018-10-31 8:47 AM

 

This is a very interesting thread for me as I'm currently looking at the Hymercar Pop-top range of vans and they all seem to be equipped with an EBL30 and twin AGM Varta batteries.

 

Alan - The Hymercar in question (my preferred choice) has not been driven in several months and with no EHU supply either so the batteries are now resting at 11.3 to 11.5v.

 

I suspect the Varta batteries will be shot by now so in your opinion which battery type and regulator would you recommend for an EBL30.

 

Regards,

 

Andrew

 

 

If you look at the chart below from Yuasa, you will see that 12.4v is about the lowest recommended level to discharge a VRLA/AGM battery. You can go below this but shortened life will result

 

Therefore batteries that have sat at below 12v for even a short length of time are going to be expired, unlikely the Starter Battery will be anywhere near it's best as well.

 

 

AGM batteries have not performed as expected and are being withdrawn by Volkswagen, Mercedes, Land rover, Seat, Audi and BMW, etc and mostly being replaced by the newer EFB technology Wet acid batteries. All the new Ultra Heavy Duty Truck batteries are also moving from AGM to EFB.

The new heavy duty Leisure batteries from Banner are all EFB, they not only say on the web site that EFB is the technology of today, but AGM's hardly get a look in.

 

We had an email recently from someone who wrote, -

"we did move to Haze: HZB-EV12-110 agm (very expensive) batteries 2 years ago, but alas they are now struggling",

 

 

We have been saying since 2014 that AGM are not a good choice for all sorts of reasons and now the automotive industry is demonstrating they are clearly not happy with them.

 

.

Our thoughts on the best motorhome batteries, and evidence behind that thinking, can be found here :

http://www.aandncaravanservices.co.uk/battery-technology.php

 

 

Don't expect the Leisure industry to start moving away from AGM batteries for a long time yet. While they are by far the most inappropriate battery for the consumer, they have major advantages to Motorhome manufacturers and Dealers.

They stand up better to 'forecourt abuse' because although they will have their life severely shortened by 'standing around' in manufacturers distribution centres and Dealers forecourts, they will hide that for a few months better than any other battery.

Obviously their life will be severely shortened, but that won't be evident initially to the consumer.

 

We think that saves the manufacturers/dealers a huge amount of money each year, which will be a major incentive to stick with AGM's, regardless of how they perform for the customer.

 

 

 

The Votronic MPPT range and the Schaudt LRM1218 are the only decent Solar regulators that we think are specifically designed for motorhomes.

The Victron MPPT range are ok, but not having dual battery capability is a significant weakness.

 

There are others about from America, but significantly greater cost than the £65 Votronic MPPT 165.

They are also designed for mega sized battery banks so the design tends to focus more on harvesting the max power and less so on 'maintaining' the batteries for the majority of the 9 months of the year when most UK motorhomes are idle.

They are therefore more likely, but not always, to overcharge a UK motorhomes battery bank.

 

 

 

 

 

1327762528_BatteryYuasastateofChargeChart.jpg.0bdd4486875a2a6ee7a9d9236a6afd37.jpg

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Thanks to Alan Keith and Derek for their replies. As you say, Alan, the manual is not very clear on this aspect of shutting down.

 

I have sent an email to Udo Lang at Schaudt to ask him specifically about disconnecting the AGMs whilst still charging the vehicle battery with the EBL. I can't download the manual unfortunately because it is much bigger than the 100kb limit for attachments but it does say " The internal charge module can also be operated without leisure battery" so hopefully he will confirm this. I have also asked whether the EBL has temperature compensation because it does seem strange that when the weather is warm the float voltage is stable at 13.7v but now it's colder, it has risen to 14v.

 

Alan - I would still prefer to disconnect the AGMs and let them discharge slowly but would appreciate your thoughts on this. My thinking stems from electrolyte loss with my previous Banner batteries. If AGMs need an even higher main charge of 14.7v I assume that this results in gassing which ought in theory convert back to H2o internally. But.... if there is loss, however small, perhaps by venting, it is irreplaceable, unlike lead acid, thereby contributing to eventual decline in performance. So the less discharge and main charge cycles there are, the longer the battery life. Does this make sense?

 

There does seem to be some confusion in my mind as to SOC for AGM batteries and the attached, from the net, seems to vary considerably from the Yuasa one you have posted. Yours suggests that at 12.5v the SOC has dropped to 50% whereas mine shows that at that voltage SOC would still be 80%. I was thinking it would be safe to allow the AGMs to drop down to 12.65 - 12.7v before recharging to give them the easiest life but wondered what you thought. The proof will come when the natural discharge rate can be established and if this was several weeks then that might be considered a positive?

1335985426_AGMbatterycharge.jpg.814f76ec4dc38abaac183925c7c67bdb.jpg

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You have clearly disregarded most of what we have said, so I don't understand why you are still asking our advice? Despite us rebuilding EBL30's, you clearly don't think we have a clue, challenging our assertion on battery isolation and temperature compensation.

 

 

As for your chart off the web, you will find thousands of them. Hardly any of them agree.

Personally I would trust what Yuasa say.

Strangely, considering the 'expert' charts you will find out there, Schaudt publish figures close to those of Yuasa.

One of these companies knows about batteries and the other is probably one of the worlds top experts on battery charging yet they seem to disagree with almost every SOC chart we have ever seen off the web.

 

 

Sorry very uncomfortable today after the recent Chemotherapy so can't be bothered to write any thing else.

 

 

.

 

 

 

 

 

 

 

.

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Just to reiterate on the SOC charts... Our gel battery has a resting voltage around 13.25V, with an explanation that the acid formula is a bit stronger than usual. Let me just say that I have an appreciation for customizable equipment as most presets (e.g. low voltage disconnects etc.) are simply useless in such cases.
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Alan - I'm really sorry to hear you are so uncomfortable and can't begin to imagine what you must be going through at the moment.

 

My original post was aimed particularly at you, hoping that you might feel well enough to be able to pass on some of your expertise in both Schaudt and AGM batteries.We all value your knowledge and efforts on behalf of motorhomers and caravanners to get the NCC battery scheme working credibly. In writing to Udo Lang I certainly haven't disregarded or challenged what you have said previously about either battery isolation or temperature compensation. Before doing so I confirmed for myself what you told me about the way battery disconnection worked and my message to him pointed this out.

 

More specifically I asked for his confirmation that what it says in the manual about the charger still working if the leisure batteries are physically disconnected is correct. If I were to use it in this way, there can be no warranty issues if the manufacturer has given specific approval.

 

Asking Udo about why the float voltage was higher than expected was again not challenging your knowledge but asking for his observations because there might possibly be a fault with my charger. Hopefully he can shed some light on this.

 

All I am ultimately wanting to do, by hopefully tapping into your expertise, is to look after my batteries in the most effective way. You have been instrumental in exposing the shortcomings of AGM batteries and particularly the damage they can do to Schaudt units. As owners, until Hymer, and the industry move in a different direction we are stuck, at least initially, with trying to look after and hopefully prolong the life of batteries we have had to pay a lot of money for.

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aandncaravan - 2018-10-31 10:14 AM

 

Bop - 2018-10-31 8:47 AM

 

This is a very interesting thread for me as I'm currently looking at the Hymercar Pop-top range of vans and they all seem to be equipped with an EBL30 and twin AGM Varta batteries.

 

Alan - The Hymercar in question (my preferred choice) has not been driven in several months and with no EHU supply either so the batteries are now resting at 11.3 to 11.5v.

 

I suspect the Varta batteries will be shot by now so in your opinion which battery type and regulator would you recommend for an EBL30.

 

Regards,

 

Andrew

 

 

If you look at the chart below from Yuasa, you will see that 12.4v is about the lowest recommended level to discharge a VRLA/AGM battery. You can go below this but shortened life will result

 

Therefore batteries that have sat at below 12v for even a short length of time are going to be expired, unlikely the Starter Battery will be anywhere near it's best as well.

 

 

AGM batteries have not performed as expected and are being withdrawn by Volkswagen, Mercedes, Land rover, Seat, Audi and BMW, etc and mostly being replaced by the newer EFB technology Wet acid batteries. All the new Ultra Heavy Duty Truck batteries are also moving from AGM to EFB.

The new heavy duty Leisure batteries from Banner are all EFB, they not only say on the web site that EFB is the technology of today, but AGM's hardly get a look in.

 

We had an email recently from someone who wrote, -

"we did move to Haze: HZB-EV12-110 agm (very expensive) batteries 2 years ago, but alas they are now struggling",

 

 

We have been saying since 2014 that AGM are not a good choice for all sorts of reasons and now the automotive industry is demonstrating they are clearly not happy with them.

 

.

Our thoughts on the best motorhome batteries, and evidence behind that thinking, can be found here :

http://www.aandncaravanservices.co.uk/battery-technology.php

 

 

Don't expect the Leisure industry to start moving away from AGM batteries for a long time yet. While they are by far the most inappropriate battery for the consumer, they have major advantages to Motorhome manufacturers and Dealers.

They stand up better to 'forecourt abuse' because although they will have their life severely shortened by 'standing around' in manufacturers distribution centres and Dealers forecourts, they will hide that for a few months better than any other battery.

Obviously their life will be severely shortened, but that won't be evident initially to the consumer.

 

We think that saves the manufacturers/dealers a huge amount of money each year, which will be a major incentive to stick with AGM's, regardless of how they perform for the customer.

 

 

 

The Votronic MPPT range and the Schaudt LRM1218 are the only decent Solar regulators that we think are specifically designed for motorhomes.

The Victron MPPT range are ok, but not having dual battery capability is a significant weakness.

 

There are others about from America, but significantly greater cost than the £65 Votronic MPPT 165.

They are also designed for mega sized battery banks so the design tends to focus more on harvesting the max power and less so on 'maintaining' the batteries for the majority of the 9 months of the year when most UK motorhomes are idle.

They are therefore more likely, but not always, to overcharge a UK motorhomes battery bank.

 

 

 

 

 

 

Why are you so clever with this sort of complicated stuff.

 

I'll catch you out one day Allan, well, probably not, lol :-)

 

Some very interesting points there about dealer forecourts and battery life etc.

 

All the best,

 

Andrew

 

 

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"Why are you so clever with this sort of complicated stuff.

 

I'll catch you out one day Allan, well, probably not, lol

 

Some very interesting points there about dealer forecourts and battery life etc.

 

All the best,

 

Andrew ".

 

 

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Sorry about being grumpy yesterday, feeling better today.

 

 

Andrew, I wish I was clever, but it is just experience of seeing so many different motorhomes with so many varied battery and electrical problems.

 

Have a look at the bottom of the Lithium batteries web page for a great example of how not to do your Solar on an EBL 30. : http://www.aandncaravanservices.co.uk/lithium-batteries.php

 

The Solara 135 unit is a pretty nasty piece of work and despite many sellers claims, is not designed for motorhomes. The manual gives a clue to it's design background where it states, " especially for rural electrification", house Solar to you and me.

 

If the same engineer did the Solar as well as the Lithium install, I am not surprised it blew up.

 

 

 

.

 

 

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