Lithium Battery

If the Lithium battery is allowed to take the charge current that it is capable of accepting then the maximum size battery that the standard Sargent/AS system can service is 60Ah and from what I read on this forum they are having to increase the fuse in the charge circuit from 20A to 25A with the 60Ah battery.

The lithium batteries include battery management circuitry that in most cases can be adjusted to control the charging current, I can only assume that the installers are doing this to allow Lithium batteries of a total of over 60Ah to be installed. If this is the case they are considerably increasing the time it will take to charge the battery(ies) and negating one of the three potential benefits of Lithium over Lead Acid. The user will still benefit from the lighter weight and greater depth of discharge but if they so use the extra capacity will have to wait for several hours of charge to replenish it so economically would have been better reverting to Lead Acid or staying at 60Ah Lithium - that will give the performance of an 110AH Lead Acid.

All of this will be totally transparent when on EHU but after three or four days off grid whether using the engine or mains charger expect it to take 8 to 10 hours to recharge.

To be honest I don't know the details, I got Conrad Anderson in Birmingham to do it for me. If it would be any help I could take some photos(its very tight in there though) of the set up if that would be any help to you. It does through the Sargent system somehow.

Hi Stuart - That would be brilliant, would much appreciate it. Kind Regards Kevin.

The lithium batteries in my garden tools wouldn't charge this morning as it was too cold in the shed - I had to warm them up in the house before I could charge them.

This made me wonder. We are used to a solar installation keeping batteries in good condition during long periods of winter storage but its possible that a long cold snap with bright sunlight days may damage cheaper Lithium batteries that don't disable charging in cold temperatures.

What’s not to like about Lithium batteries? Smaller, lighter and greater longevity. Me and my fellow golfers would never go back to a lead acid battery golf trolley! It’s one of the major reasons that EVs are now replacing combustion engine cars (that and UJTs). However, just like lead acid, they require their own charging regime and it’s true of all lithium batteries whether they are in your smart phone or an EV that if you charge to 100% every time the life will be reduced. Cars have very sophisticated battery management systems (BMS) that prevent charging to 100% and fully discharging.

What I am not clear about is how the Sargent BMS works to maintain the life of a lithium battery but if it works correctly most of us will never need to replace the leisure battery which is more than can be said for lead acid.

Born Again,  the other thing to take into account is the BMS built into the Lithium Battery, unfortunately, the Li Batteries Autosleeper are using are not particularly sophisticated, and for instance, I can find no cut off to prevent the Battery from charging at low temperature and the dealers I have spoken to have all said that they had not been told that lithium batteries should not be charged at low temps (even though it states this on the battery data sheet.

Kevinktwo wrote:Born Again,  the other thing to take into account is the BMS built into the Lithium Battery, unfortunately, the Li Batteries Autosleeper are using are not particularly sophisticated, and for instance, I can find no cut off to prevent the Battery from charging at low temperature and the dealers I have spoken to have all said that they had not been told that lithium batteries should not be charged at low temps (even though it states this on the battery data sheet.

I dismantled and repaired a lithium battery pack and, as you say, they have a control module but also the charging regime is different so you cannot replace a lead acid directly with lithium. A good BMS prevents low temperature charging and limits the charging range. Having said that, our experience with lithium batteries even with basic chargers is that you get a substantially longer life plus, of course, the size and weight advantage. They are the future but come at quite an additional cost.

We have a 2017 Broadway FB and because our two lead acid batteries were not holding power when off grid we opted to go with Lithium.

We had a 120amp Lithium fitted but also needed a Victron shunt, a Victron solar regulator and a B2B. We were warned at the time that the Sargent charger we had was ok but we would be better off changing the charger. (Sargent charger wants to go into float mode at 13.6v and  Lithium want to be charged up to 14.2 - I may have the numbers slightly wrong but they're in that ball park). In order to get the charger to top the battery up to the 14.2 it was suggested to switch something on that had a draw bigger than 2amps and it would force the Sargent to fully top it up.

So the van sat outside on mains for the last 10 days and I've been able to monitor what's going on as the Victron units (shunt and solar reg) can feed Bluetooth apps and you can see what's going on.

What transpired is the battery not being charged up as expected. It should have gone into float mode but it appeared it was turning itself off and then the battery started to drain. This may well explain the problem with my old batteries.

So I phoned Sargent and explained the issue. They informed me that they had some faulty chargers from around 2017 but these were extremely rare and they'd only found a few. But it would explain some of the characteristics that I was seeing. They would supply me with a replacement charger for the cost of £150 (now out of warranty!!), but....... "I would be better off replacing with another manufacturers charger, as the Sargent ones aren't good enough for lithium.

My charger is being replaced with a Victron one so I'll update after then. I intend to follow up with Sargent in the next few weeks. If they knew of the fault should that not have been a recall?

I upgraded to the 84Ah Lithium battery rather than the default 60Ah. First couple of trips, Fuses blown, so replaced 20A fuses in battery circuit with 25A on advice of dealer. On return from a trip about 4 weeks ago, battery went to zero after about a week. I was pretty certain that everything was switched off. Dealer advised charge and see what happens. Two weeks ago put van away for the winter with fully charged battery, and double checked everything switched off. Battery steady at 13.3V for about 10 days. Now dipping, reached 11.8V today, expecting call from Sargent soon to say Leisure Battery flat. Anyone else experienced this?

I have been down to auto sleepers workshop today to sort out my 12v electrics. Firstly let me say I think they may have sorted it at last but time will tell.  I have a Nov 21 Warwick duo ,I believe the 12v system was installed at a price  to suit not to a required quality standard.
We prefer wild camping as against sited with ehu.showers,water facilities.
, though we do touch bases every few days to top up and empty water etc if needed.
With the electrics based on a 65amp battery and an 80 watt solar panel winter wild camping is nigh impossible if you wish to remain comfortable. A/s admit they are on a learning curve with lythium electrics.     So today I had fitted a 100 amp Roamer battery . A Sargent b to b charger and an upgrade of fuses in the em 50 fuse box. Today I was able to throw away all the blown fuses I have replaced even the uprated ones that were blown in the last twelve months   Too many times I have had battery shutdowns , fuses blown. And heaven knows how many messages from Sargent telling me one or the other battery was low. So today I came home thinking I might start to enjoy my investment instead of wondering what’s going to go wrong this time. My fridge still doesn’t work on gas which is awkward for off site camping but winter coming will help solve that till the Dometec  spare motherboard arrives . Such is motorhome enjoyment

We have 200A of lithium and an appropriate charging system fitted by RoadPro.        120w solar panel.         It works really well and the batteries recharge at 50A from the engine.     We are mostly away from EHU and have 2 periods each year of 10 days at regattas without resorting to EHU or engine charging (April/May and August).

We also have a share in a yacht in Greece and have 200A of Lithium and a Victron charging system.    300w of Solar.     On yachts in Greece the fridge runs on 12v for 24 hours a day and that is the major drain on batteries.    The system copes OK but ofcourse there is plenty of sunlight.      Not so relevant to motorhomes is that the angle that the batteries are at doesn’t make any difference to lithium - whereas lead acid batteries on actively used yachts will be lucky to survive 2 seasons!

Don't know if this has been mentioned.

I take my van for a run just to keep said batteries topped up, but the lithium battery shut down and I had a call from sgt asking if all was well.

I took the van to willersea and was told that as I have start stop and an intelligent alternator the leisure battery would stop being charged once the vehicle battery was fully charged, so if I drove just ten miles and the vehicle battery was fully charged the alternator would stop charging no matter what state the lithium was in.

they just happened to have a b to b in stock and fitted it (quite expensive) but has fixed the problem.

Pete

If it is of interest, our Bourton is fitted with two 60Ah Lithium batteries and after 12 months, they have worked well, although we do not normally spend more than one night wild camping.

From March to October the 80 watt solar panel keeps the batteries charged when the van is not in use.

StuartB wrote:
I was in a similar position when ordering our A/S, I also convinced A/S to upgrade to 100amp, they told me they simply didn't fit any second batteries. I think they suggested I ask the dealer to do that. I actually ended up getting someone else to fit another 100amp battery, so we now have 2 batteries which have worked fine so far. We can use them for 2 or 3 days without EHU quite easily. We are not sure if we need to take any more steps, like adding solar or a new B2B charger to make the most of the Lithium battery capabilities. Currently we like a combination of non EHU and campsites with EHU. Next week I am going try 4/5 days without EHU to see how that goes.
After talking to the specialist who fitted my second battery I think it would get quite expensive to add/adapt solar and fast charging to the Sargent equipment fitted. I suppose it very much depends how you want to camp, I have been quite impressed with the Sargent set up whenever we have been on EHU. And I suspect the main A/S market is for people who spend heir time on EHU campsites, nothing wrong with that. We are hoping to spend much more time in Europe next year, so for us that will be the test to see whether need any more 'off EHU' capability.

Hi Kevin and Stuart

Just checking 

Kevin is saying that AS haven't fitted supporting electrics for Lithium, but Stuart comments that doubling up the batteries isn't a problem.
Apologies as I am a bit confused, and am thinking of contacting AS for a battery upgrade on our ordered Warwick. There will be an 85W solar panel on the van.
We would like to spend up to 4 days at a time off grid.

Any advice gratefully received

I’m not up to date with the latest lithium/charging setup fitted by A/S apart from the fact they have admitted they are still playing catchup with the technology. That doesn’t exactly fill me with confidence!!
These lithium batteries are not exactly cheap and everybody’s requirements are different but if they are still only fitting 85W of solar on the roof, I would be thinking of increasing that and improving the solar regulator as a relatively inexpensive starting point.

Dbvwt wrote:I’m not up to date with the latest lithium/charging setup fitted by A/S apart from the fact they have admitted they are still playing catchup with the technology. That doesn’t exactly fill me with confidence!!
These lithium batteries are not exactly cheap and everybody’s requirements are different but if they are still only fitting 85W of solar on the roof, I would be thinking of increasing that and improving the solar regulator as a relatively inexpensive starting point.

That sounds very sensible - but a bit worrying that there are now a lot of users who are basically saying that the brand new set up as purchased isn’t fit for purpose in that it doesn’t support any real off grid at all.

This is just my opinion but sadly A/S haven’t really designed their systems for proper off grid use long before the latest lithium installs and their problems.
You only have to read all the upgrade threads that have frequented the forum for many years.

The vast vast number of AS buyers are not the slightest interested in spending any great length of time away from battery charging and for them, the standard 60AH Lithium with light weight, very long life and faster charging rate is ideal.

I agree Peter, when I’m on a site I always have a wander around to have a nose at all the vans, especially other Autosleepers. It’s very rare to see another one that is not on EHU. That’s not confined to A/S by the way, I’m often the biggest van not on EHU.
If you want decent off grid performance then I’m afraid modifications to vehicles (even brand new) is usually needed.