Adding an Extra Leisure Battery

[VXman]

Getting a new Burstner very soon which has just one Leisure battery. Just thinking for peace of mind a 2nd one might be useful. The one fitted is the AGM type 95AH.

Are there any things I should be aware of. Is it just a case of linking the 2 batteries together? Do they need to be the same type - I suppose mixing a Lithium with a AGM is not a good idea.

Any guidelines/advice/suggestions/possibilities?

 

[Raul]

I would recommend to link with the same type and size, others my think different. Adding Li to lead is a big no no.

 

[Stealaway]

Getting a new Burstner very soon which has just one Leisure battery. Just thinking for peace of mind a 2nd one might be useful. The one fitted is the AGM type 95AH.

Not cheap but a good price from here-

12v 95AH Varta AGM Dual Purpose Leisure Battery LA95 (N/A) - Alpha Batteries

Varta 12v 95ah LA95 AGM Leisure Battery Why VARTA® Professional Dual Purpose AGM batteries? Powered by Johnson Controls Power Solutions, VARTA® Professional […]

www.alpha-batteries.co.uk

I didn't trust AGM so I sold mine and bought two wet leisure battery instead

 

[VXman]

I didn't trust AGM so I sold mine and bought two wet leisure battery instead

Really? Why? AGM batteries are used in modern stop/start car situations because of their ability to recharge quickly. Seem suited to Motorhome leisure situations.

Informative website here - a few negatives but seems on the whole to be better than the traditional battery.

Absorbent Glass Mat (AGM) Battery Information - Battery University

Learn what differentiates Absorbent Glass Mat (AGM) batteries from other lead acid battery types

batteryuniversity.com

 

[VXman]

Adding Li to lead is a big no no.

What about a Li but using separately?. Could be switched. Like a back up/take in turns. It could be a pain in the neck managing I realise.

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[Lenny HB]

AGM's are crap for leisure use got rid of mine and fitted 2 Gels (transfered from last van), then added a 3rd.
Last van had AGM's they lasted 18 months. 2 of my Gels are 5 years old and one 4 years still performing like new.

 

[Two on Tour]

Really? Why? AGM batteries are used in modern stop/start car situations because of their ability to recharge quickly. Seem suited to Motorhome leisure situations.

Informative website here - a few negatives but seems on the whole to be better than the traditional battery.

Absorbent Glass Mat (AGM) Battery Information - Battery University

Learn what differentiates Absorbent Glass Mat (AGM) batteries from other lead acid battery types

batteryuniversity.com

Ask Lenny HB for his views on AGM batteries.

Edit : arrived on que.

 

[Lenny HB]

I didn't trust AGM so I sold mine and bought two wet leisure battery instead

A sensible man.

 

[Bessy765]

I have a 2019 Burstner Iexo 736. it came with one battery the Varta 95ah AGM battery.this is under the drivers seat. I fitted a second identical one. It’s a very tight fit, using some carpet cut offs to make sure neither battery rubs against the seat frame. The earth is left on the original battery the positive is taken from the new battery with the negative to negative and positive to positive terminals linked with the same size cable as the existing wiring. If like mine you have to tell the system you have more battery capacity. On the rotary dial turn to the battery voltage setting hold the dial in till it flashes it should read 95 turn the dial until 190 and press again until it flashes then release. This tells the system what has happened.
be advised the seat has to be removed to accomplish this and its very heavy and has sharp edges protect the furniture

 

[Raul]

What about a Li but using separately?. Could be switched. Like a back up/take in turns. It could be a pain in the neck managing I realise.

Separate yes, but when it comes to charge that will have to be done separate to. If you wanna save the weight and hassle of lead, or separate chemistries, change now to full Li. I would in a second. No regrets.

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[AgeingAndrew]

When we bought our van, it came with a single Banner 95Ah AGM, which has now been replaced. I only changed the AGM because it was 6 years old and I needed more battery capacity so that I could stay off-grid for longer than 2-3 days. I rarely discharged it below 50% and never left it in a discharged condition, I had no problems with it whatsoever.

If you are going to fit a second battery make sure your charger can handle the additional demand and that it will charge at the recommended charging voltage. Banner recommended the charging voltage between 14.4-14.8V for my Banner AGM battery.

 

[Lenny HB]

When we bought our van, it came with a single Banner 95Ah AGM, which has now been replaced. I only changed the AGM because it was 6 years old and I needed more battery capacity so that I could stay off-grid for longer than 2-3 days. I rarely discharged it below 50% and never left it in a discharged condition, I had no problems with it whatsoever.

If you are going to fit a second battery make sure your charger can handle the additional demand and that it will charge at the recommended charging voltage. Banner recommended the charging voltage between 14.4-14.8V for my Banner AGM battery.

You were a lucky bunny, Banners are the worst AGM's that is what was in my last van both failed at 18 months and mine were never discharged below 50%.
At the time there were loads of reports of them failing at 12 months on the German forums.

 

[Tombola]

BIn it / sell it and replace with lithium if set up /wires/mppt etc allow

long run lithium is far better and added to the cost of a new van wont be significant

 

[VXman]

You were a lucky bunny, Banners are the worst AGM's that is what was in my last van both failed at 18 months and mine were never discharged below 50%.
At the time there were loads of reports of them failing at 12 months on the German forums.

I've seen decent AGM's with 4 year warranties (maybe there are some 5 years - not looked that closely) so one would assume manufacturer's feel they are reliable enough to offer these.

 

[Lenny HB]

I've seen decent AGM's with 4 year warranties (maybe there are some 5 years - not looked that closely) so one would assume manufacturer's feel they are reliable enough to offer these.

You can get professional AGM often used in UPS's but at the price level those are what's the point might as well fit Lithium.
The ones fitted to Motorhomes are labeled Dual Purpose so they are a starter battery, better to ditch them and fit Gels.

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[rod_vw]

I'm waiting for two AGM 120Ah Leisures to be delivered today, I had two wet Banners and both have failed at four years old. I know they have both failed as I have tried them separately and neither will hold a charge.

The engine battery is an AGM which I have had to change at four and a half years from new. However I can't comment on its lifespan as when I re-coded the vehicle (Volkswagen engine with intelligent charging system coded to the battery type) I discovered that the coding was not correct for the one that came off even though it was new from the factory.

The new AGMs are from Advanced Battery Supplies and are these https://advancedbatterysupplies.co.uk/product/advanced-agm-lp120-leisure-battery/ time will tell how good they are but they do offer a five year warranty.

 

[Lenny HB]

I'm waiting for two AGM 120Ah Leisures to be delivered today, I had two wet Banners and both have failed at four years old. I know they have both failed as I have tried them separately and neither will hold a charge.

The engine battery is an AGM which I have had to change at four and a half years from new. However I can't comment on its lifespan as when I re-coded the vehicle (Volkswagen engine with intelligent charging system coded to the battery type) I discovered that the coding was not correct for the one that came off even though it was new from the factory.

The new AGMs are from Advanced Battery Supplies and are these https://advancedbatterysupplies.co.uk/product/advanced-agm-lp120-leisure-battery/ time will tell how good they are but they do offer a five year warranty.

Does your charger have an AGM profile as if they are charged at a too lower voltage they won't last long.
I personally would never use AGM's for a leisure battery.

 

[AgeingAndrew]

As I said in my response earlier in this thread my Banner AGM lasted 6 years. It was charged by the 18A charger in an EBL29 on a GEL profile, my EBL does not have an AGM profile.

Vxman has stated that he is ‘just thinking for peace of mind a 2nd one might be useful...’ and he has asked what should he be aware of if adding a second.

I think that Vxman should see how it goes with the 1 AGM battery. If his usage of the battery is light then it could last years; if he intends to use camp sites with EHU then one battery may well be enough.

If VXman is going to live full time in the van, or spend a lot of time off-grid, then an additional battery or changing to lithium could be worthwhile.

But before he does anything he should satisfy himself that his existing battery is being correctly charged and should understand the capability and capacity of the existing charging system.

 

[Raul]

There you go, a good charging rate keeps battery happy. I’m trying to tell folk that you need at least 10a charging for every 100ah storage, a C/10 rate. That’s a good example, agm are able to gobble amps, and a 18a charger has kept a 100a agm happy for 6 years. For true agm it actually needs a C/5 rate, that’s 20a charging for 100ah storage. The voltage if is close to 14,4v is fine, any higher you need temperature compensated charging.

 

[rod_vw]

Does your charger have an AGM profile as if they are charged at a too lower voltage they won't last long.
I personally would never use AGM's for a leisure battery.

I'm using a RING RSCDC30 B2B charger plus a 100W solar which feeds via the MPPT portion of the RSCDC30. Bulk(Absorption) Voltage is set at 14.6v, Float at 13.6v the B2B will charge at up to 30A. The voltages are configurable.

The vehicle is a VWT6 with smart alternator technology including Stop-Start and is in almost everyday use so always kept well charged.

I've not got anything sophisticated to monitor the batteries with beyond a BM-1 Monitor with Bluetooth connectivity.

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[BillyKontiki]

Getting a new Burstner very soon which has just one Leisure battery. Just thinking for peace of mind a 2nd one might be useful. The one fitted is the AGM type 95AH.

Are there any things I should be aware of. Is it just a case of linking the 2 batteries together? Do they need to be the same type - I suppose mixing a Lithium with a AGM is not a good idea.

Any guidelines/advice/suggestions/possibilities?

Hi replaced my AGM 100 ah with 100 ah lithium half the weight, and almost twice the usable amp hours.
A bit expensive but worth every penny.

 

[Clive Mott]

Although in principle I would agree that Adding Li to lead is a big no no. But this is exactly what Hymer do with BOS Lithium batteries and those 95ah Varta AGM batteries. It keeps the BMS small as large peak loads come from the AGMs which get topped up by the Li batteries. Personally a largish Li with a big BMS does it for me.

 

[Garry - June]

If you plan going places without EHU don't forget to fit as much solar on the roof as you can...

 

[Lenny HB]

Although in principle I would agree that Adding Li to lead is a big no no. But this is exactly what Hymer do with BOS Lithium batteries and those 95ah Varta AGM batteries. It keeps the BMS small as large peak loads come from the AGMs which get topped up by the Li batteries. Personally a largish Li with a big BMS does it for me.

I ve never liked Hymers way of doing it seems a bit of a hotch botch, why would you want to put an unreliable AGM with a Lithium.

 

[DT]

I added a second battery to my new Burstner 690 which was a real struggle. As others describe the seat is heavy and not an easy thing to remove, second battery is a tight fit and needs protection/padding. Wish they had been installed under the single seat base by the habitation door. I have a fault with my transformer rectifier which means that the solar was not working all winter. During the shorter days I doubt the 100w panel would keep the batteries charged so I took them home. Since February I have put a 100w panel inside the windscreen with a spare charge controller connected to the batteries. Had to leave the driver seat off to gain access to all this which pees me right off.

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[AndyVW]

Its sure we have all had a bad experience, with one product or another, ( I hate hotpoint washing machines)
But I,ve learnt over the years, we customers are the best final testers, and if everybody says one product is a failure
sure as eggs are eggs, it will disappear from the shelves.... They keep selling Hotpoints ! so it must be me.