Changing to a Lithium Leisure battery

[chris1949]

We have a 2021 Burstner 745 and want to change the leisure battery to one with more storage capacity. I have been receiving conflicting information as to whether I can do a straight swap for the 85 Ah lead acid to a 200 Ah lithium battery (of the same physical size). We have a Burstner fitted 120 watt PV cell on the roof. Some say yes, just change it; others say no because the Burstner charger isn't compatible. Any advice please? Thanks, Chris

 

[Rockpool]

Your laptop may charge from 12volt. Mine will not. (and Noah probably still has the other one on the Ark)

Yes, the toothbrushes will, but my comment was more of an example for anybody who has existing small 240v equipment which they would like to charge without EHU.

I could list other such things, but it will only give the oportunity for somebody to say otherwise.

Yes agree that some people may need an inverter to charge their smaller appliances, but there are also alternative ways to charge small appliances without an inverter

 

[rosalan]

When I asked for an inverter to be fitted, they fitted a modulated unit, they did not have pure sine wave in stock. The modulated is cheaper. To date it has worked well but not on toothbrushes! It melted their charger.

 

[rosalan]

At Lincoln show there were 5 or 6 stands selling Lithium products but really only one make of lithium battery LithiumPro and one make of ancillary equipment in blue boxes. I just hope they were a good choice for me.

 

[jumar]

I listened to very informative sources when I converted our Hymer to Lithium... didn't short cut, bought one of the best branded batteries on the Market, Roamer..and as a battery is a power storage item, I was advised to provide it with the most practical means of recharging it...these being Solar with an MPPT controller to use whilst stationary, and a DC2DC charger whilst in motion...
Two years down the road, I can honestly say it's been well worth the effort, time and money..
I have since upgraded to more amperage to make our system even more efficient...
We charge eMTBs daily and have recently ventured into using 220v cooking appliances, so far on our current trip, everything is very sustainable...

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[Wanders from Glos]

Your laptop may charge from 12volt. Mine will not. (and Noah probably still has the other one on the Ark)

Yes, the toothbrushes will, but my comment was more of an example for anybody who has existing small 240v equipment which they would like to charge without EHU.

I could list other such things, but it will only give the oportunity for somebody to say otherwise.

No mine won’t charge from 12v either. I disregarded all that, because it depends on the things people want to charge.

I think it’s a matter of expectation. We have decided if we are going to Lithium we want everything to work as if connected to an EHU abroad without worry. Just plug it in and go. Equally we want to be able to stay in one place for quite a few days so efficient charging and discharging is important. That extra 10% could make all the difference.

If it works for the OP that’s fine, Lenny HB was simply pointing out just swapping the batteries may not be as successful as hoped. If it’s enough for the OP I guess that’s fine. For me it’s a half measure.

 

[Wanders from Glos]

I listened to very informative sources when I converted our Hymer to Lithium... didn't short cut, bought one of the best branded batteries on the Market, Roamer..and as a battery is a power storage item, I was advised to provide it with the most practical means of recharging it...these being Solar with an MPPT controller to use whilst stationary, and a DC2DC charger whilst in motion...
Two years down the road, I can honestly say it's been well worth the effort, time and money..
I have since upgraded to more amperage to make our system even more efficient...
We charge eMTBs daily and have recently ventured into using 220v cooking appliances, so far on our current trip, everything is very sustainable...

We are taking the same approach.

 

[peterc10]

My computers did not charge at 12v, but I still found car plug adaptors that charged them by increasing the voltages they needed. I also have 12v adaptors for my TV, toothbrush, razor, rechargeable AA batteries, camera etc etc.

I now have a full lithium set up with more solar and batteries and a 2000w pure sine wave inverter. But I still use my low voltage adaptors for low voltage electronics. That is because I don't want to waste power converting 12v DC to 240v AC and then convert that back again to low voltage DC.

 

[Wanders from Glos]

My computers did not charge at 12v, but I still found car plug adaptors that charged them by increasing the voltages they needed. I also have 12v adaptors for my TV, toothbrush, razor, rechargeable AA batteries, camera etc etc.

I now have a full lithium set up with more solar and batteries and a 2000w pure sine wave inverter. But I still use my low voltage adaptors for low voltage electronics. That is because I don't want to waste power converting 12v DC to 240v AC and then convert that back again to low voltage DC.

That all makes sense. For me it’s too much faff, I want to just plug stuff in. I use my PC for my research, and some of the data is too sensitive for a cloud. I do backup it up but unless I have an Apple approved device to charge from a 12v plug I will use 240v.

 

[PlacidoD]

My received wisdom from the many threads I have read:

• It is just about possible to swap out a 100 Ah flooded lead-acid for a 100Ah lithium without making any other changes assuming your mains charger has a gel setting (Mine does). That will almost double you realistic available capacity.
• Anything much above 100 Ah and you really need all the "bells and whistles" ancillary equipment to go with it.
• It is just not economic to spend £2k+ on my 2007 Hobby T500 or any similar older van doing a "bells and whistles" installation. (This assumes I install. More if others do the job.)
• The main reason for a limit of circa 100Ah without a B2B is that the lithium battery will have a voracious appetite for charge from the alternator. So long as you do not have a modern van with a smart alternator 100Ah should work OK.
• The main reason for upgrading the EHU charger would be that the lithium can charge at a much faster rate than a FLA battery but also you can charge to 100% rather than circa 90%. That is an easy DIY swap so I might get round to doing that eventually.

My leisure battery began to fail on my 2nd outing post purchase so I had to do a lot of reading to decide what to do over barely a week so as to have the van ready for another trip so I replaced the failing 85Ah flooded lead-acid with a 110 Ah one at a cost of circa £90 (and changed all my lights to leds). When that battery starts to fail my plan is to drop in a circa 100Ah lithium with bluetooth BMS and do nothing more. (I am not sure I have the skills to fit a B2B). When the time comes I shall be looking for a circa 315 x 175 x 190 Lithium. Not sure that size exists at an affordable price atm. There is bound to be more choice in a couple of years and prices will likely be better.

At the moment my current configuration suits me. I tend to pile on the miles between sites and aim to be on an EHU every other night but would be comfortable with two in summer given my solar panel and lack of draw from the Truma heating. It would be nice to be able to manage three nights without EHU. I could then "Do a Lenny" and not plan or pre-book any sites before boarding the ferry! Since installing my new battery I have never been below 75% (judging from the crude led readout) so I maybe need to push the boundaries a little. The main attraction of lithium for me would be an ability to charge my Ebike without an EHU (I have a small portable inverter that will plug in a cigar lighter socket) and watch TV without worrying about battery drain. I suppose I might then start looking for an inverter that can power my Lavazza coffee pod machine but one step at a time!

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[peterc10]

That all makes sense. For me it’s too much faff, I want to just plug stuff in. I use my PC for my research, and some of the data is too sensitive for a cloud. I do backup it up but unless I have an Apple approved device to charge from a 12v plug I will use 240v.

No more faff than plugging in your stuff to the very few 240v sockets that motorhomes have as standard. In fact it is easier with phones, watches etc that support wireless charging. Just place them on their wireless chargers which are permanently plugged in. However I do have more 240v, 12v and 5v USB sockets fitted in my motorhome by the converter, dealer and myself.

As for Apple appliances my wife has an iphone, iwatch and ipad and just uses their standard USB cables plugged into the 5v USB slots I have installed. Not sure about imacs but, as I understand it, new ones will have to be using USB C slots in the future for those sold in Europe.

 

[Wanders from Glos]

No more faff than plugging in your stuff to the very few 240v sockets that motorhomes have as standard. In fact it is easier with phones, watches etc that support wireless charging. Just place them on their wireless chargers which are permanently plugged in. However I do have more 240v, 12v and 5v USB sockets fitted in my motorhome by the converter, dealer and myself.

As for Apple appliances my wife has an iphone, iwatch and ipad and just uses their standard USB cables plugged into the 5v USB slots I have installed. Not sure about imacs but, as I understand it, new ones will have to be using USB C slots in the future for those sold in Europe.

Apple Mac has come with USB C for a few years now and the charger it comes with is the same. That bit is 30W.

We are fortunate in we have quite a few 240v sockets (5) but only one 12v not on the van battery so we are the other way round. Hence the faff with 2 bike batteries to charge, and PCs.

But, what I have been trying to say, obviously not very well, is that this seems personal preference to me. It’s not a criticism of the way you do things, just not my preference and OP wanted to understand different approaches.

 

[peterc10]

• The main reason for a limit of circa 100Ah without a B2B is that the lithium battery will have a voracious appetite for charge from the alternator. So long as you do not have a modern van with a smart alternator 100Ah should work OK.
• The main reason for upgrading the EHU charger would be that the lithium can charge at a much faster rate than a FLA battery but also you can charge to 100% rather than circa 90%. That is an easy DIY swap so I might get round to doing that eventually.

Smart alternators alone will charge the lithium battery at a high rate, but they will not charge it to its full capacity. They will if you use a B2B. And the other advantage of using a B2B is that it protects your alternator from overheating when the lithium battery is charging at high rates for long periods.

 

[Lenny HB]

My received wisdom from the many threads I have read:

• It is just about possible to swap out a 100 Ah flooded lead-acid for a 100Ah lithium without making any other changes assuming your mains charger has a gel setting (Mine does). That will almost double you realistic available capacity.
• Anything much above 100 Ah and you really need all the "bells and whistles" ancillary equipment to go with it.
• It is just not economic to spend £2k+ on my 2007 Hobby T500 or any similar older van doing a "bells and whistles" installation. (This assumes I install. More if others do the job.)
• The main reason for a limit of circa 100Ah without a B2B is that the lithium battery will have a voracious appetite for charge from the alternator. So long as you do not have a modern van with a smart alternator 100Ah should work OK.
• The main reason for upgrading the EHU charger would be that the lithium can charge at a much faster rate than a FLA battery but also you can charge to 100% rather than circa 90%. That is an easy DIY swap so I might get round to doing that eventually.

My leisure battery began to fail on my 2nd outing post purchase so I had to do a lot of reading to decide what to do over barely a week so as to have the van ready for another trip so I replaced the failing 85Ah flooded lead-acid with a 110 Ah one at a cost of circa £90 (and changed all my lights to leds). When that battery starts to fail my plan is to drop in a circa 100Ah lithium with bluetooth BMS and do nothing more. (I am not sure I have the skills to fit a B2B). When the time comes I shall be looking for a circa 315 x 175 x 190 Lithium. Not sure that size exists at an affordable price atm. There is bound to be more choice in a couple of years and prices will likely be better.

At the moment my current configuration suits me. I tend to pile on the miles between sites and aim to be on an EHU every other night but would be comfortable with two in summer given my solar panel and lack of draw from the Truma heating. It would be nice to be able to manage three nights without EHU. I could then "Do a Lenny" and not plan or pre-book any sites before boarding the ferry! Since installing my new battery I have never been below 75% (judging from the crude led readout) so I maybe need to push the boundaries a little. The main attraction of lithium for me would be an ability to charge my Ebike without an EHU (I have a small portable inverter that will plug in a cigar lighter socket) and watch TV without worrying about battery drain. I suppose I might then start looking for an inverter that can power my Lavazza coffee pod machine but one step at a time!

Sounds like you use EHU a fair bit so it would be advisable to fit a mains charger with a Lithium profile. I wouldn't fit any Lithium without B2B too risky IMO. Don't know what solar you have but the solar controller will need a Lithium profile.

You could fit a 100ah Lithium, new mains charger B2B & new solar controller for around £800 if doing it yourself and that is using decent Victron gear.

Have a chat with RogerIvy at OffGrid you get a Funster discount.

 

[autorouter]

Smart alternators alone will charge the lithium battery at a high rate, but they will not charge it to its full capacity. They will if you use a B2B. And the other advantage of using a B2B is that it protects your alternator from overheating when the lithium battery is charging at high rates for long periods.

A smart alternator will dial the voltage down when it thinks the starter battery has a reasonable charge, but isn't full. If there is a split charge relay connecting the lithium battery to the starter battery (ie no B2B) then the highest voltage item will be the lithium battery, at about 13.4 to 14.0V depending on its state of charge. It will charge the starter battery until it's full. It will also power the fridge, and if it's a 3-way type then that will be about 15A. The result is you arrive at your destination with a 100% full starter battery, a cold fridge and a flat leisure battery.

In that situation, even a small 20A or 30A B2B would be beneficial, if only to stop the discharge.

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[bigtwin]

@Lenny HB was simply pointing out just swapping the batteries may not be as successful as hoped.

I don’t think so. In his many posts on the matter Lenny HB (example below) clearly seeks to get the maximum possible benefit from the investment.

you will never get the best out of the Lithium.

In relation to the bolded part in your quote, I refer you to my earlier quote (below). It is doubtful that anyone swopping to LiFePO4 (irrespective of how ideal, or not, the charging arrangements are) would ever be disappointed with the improvement gained.

Indeed, if something is 1000% better than you had before, achieving only 900% of the improvement isn’t really that much of an argument against it.

Ian

Ian

 

[PlacidoD]

A smart alternator will dial the voltage down when it thinks the starter battery has a reasonable charge, but isn't full. If there is a split charge relay connecting the lithium battery to the starter battery (ie no B2B) then the highest voltage item will be the lithium battery, at about 13.4 to 14.0V depending on its state of charge. It will charge the starter battery until it's full. It will also power the fridge, and if it's a 3-way type then that will be about 15A. The result is you arrive at your destination with a 100% full starter battery, a cold fridge and a flat leisure battery.

In that situation, even a small 20A or 30A B2B would be beneficial, if only to stop the discharge.

I am agree that a B2B is a first priority. Trouble is, unlike a mains charger which is a simple swap I am far from confident that I have the skills to install a B2B. The thought of routing really heavy duty cables from under my driver's seat through to the engine compartment on my Transit chassis and disabling the existing arrangement is off putting. Maybe I need to watch a few videos!!!

A passing thought: I presume I can take my time installing a small B2B e.g. if I can acquire a used one where someone is upgrading at a good price and do it over this winter then stick with my flooded lead-acid until it is way past its best (Which is bound to happen at the most inconvenient time!) I can then slot in lithium with a minimum of fuss?

However the more I read of "You must have this, You must have that" the more I begin to feel that a gel battery would be simpler next time now that I know that my EHU charger has a gel setting!!! But I am also now reading about EFBs - Enhanced Flooded Batteries. The more I read the more I am confused!!!

 

[Jimbohorlicks]

My received wisdom from the many threads I have read:

• The main reason for upgrading the EHU charger would be that the lithium can charge at a much faster rate than a FLA battery but also you can charge to 100% rather than circa 90%. That is an easy DIY swap so I might get round to doing that eventually.

Rather than buying an expensive ehu charger to replace your van charger, why don't you look at buying a lithium charger that you can just plug in when your on ehu hook up. There are lots out there.

 

[PlacidoD]

A smart alternator will dial the voltage down when it thinks the starter battery has a reasonable charge, but isn't full. If there is a split charge relay connecting the lithium battery to the starter battery (ie no B2B) then the highest voltage item will be the lithium battery, at about 13.4 to 14.0V depending on its state of charge. It will charge the starter battery until it's full. It will also power the fridge, and if it's a 3-way type then that will be about 15A. The result is you arrive at your destination with a 100% full starter battery, a cold fridge and a flat leisure battery.

In that situation, even a small 20A or 30A B2B would be beneficial, if only to stop the discharge.

On re-reading your post I am not 100% clear whether you are saying that is what will happen with a smart alternator thus implying the same would not apply to older alternator such as on my 2007 Hobby T500 Van. Can you clarify?

 

[Lenny HB]

On re-reading your post I am not 100% clear whether you are saying that is what will happen with a smart alternator thus implying the same would not apply to older alternator such as on my 2007 Hobby T500 Van. Can you clarify?

He is referring to a smart alternator it wouldn't apply to you.

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[autorouter]

On re-reading your post I am not 100% clear whether you are saying that is what will happen with a smart alternator thus implying the same would not apply to older alternator such as on my 2007 Hobby T500 Van. Can you clarify?

A non-smart standard alternator just pushes out a constant voltage of over 14V, so it will always be higher than either of the batteries. So the scenario of the leisure battery charging the starter battery and supplying power doesn't happen.

There are of course other reasons why you might want a B2B. An alternator pushes out a voltage over 14V, and doesn't control the amps. It can sometimes push out excessive amps when the lithium battery is very flat. This can cause the alternator to overheat. A B2B with a lithium profile will control the amps to a definite amount, to avoid that problem.

Also in summer you tend to forget about the problem of never charging a lithium battery when it's freezing cold. A B2B can have a lithium profile with a temperature sensor that cuts off the charge below about 2°C.