Lithium drop in replacement

I’m reading more and more of people having lithium batteries installed as a straight drop in replacement for the standard lead acid. Has anyone done it with a van conversion running through the sargeant  system ????

I can see the obvious performance, size etc… benefits of lithium batteries but at this moment they are silly money compared to a lead acid.
I camp off grid frequently and my power usage is typical of most others. If it wasn’t for the Sargent EC500 (let’s not go there for now!) my 110ah lead acid and standard 80w solar panel is more than adequate for my needs.
Can someone explain why, at this moment in time, there seems a trend for upgrading to lithium at great cost? For the majority, I can’t see the benefit.
Sorry Alan, didn’t mean to take your thread off in a different direction!

Dbvwt wrote:I can see the obvious performance, size etc… benefits of lithium batteries but at this moment they are silly money compared to a lead acid.
I camp off grid frequently and my power usage is typical of most others. If it wasn’t for the Sargent EC500 (let’s not go there for now!) my 110ah lead acid and standard 80w solar panel is more than adequate for my needs.
Can someone explain why, at this moment in time, there seems a trend for upgrading to lithium at great cost? For the majority, I can’t see the benefit.
Sorry Alan, didn’t mean to take your thread off in a different direction!

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I agree with you David, no problem this year, not been on EHU yet and never run out of juice
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Richard

I really don’t see the point of a Lithium leisure battery as a drop-in replacement when the existing charging circuit isn’t rated to deliver the higher charging current demanded by Lithium to realise its full benefit.

Unless you take a complete system approach and upgrade charger, alternator, cabling and solar, then the advantage of Lithium seems very restricted. 

Tim

I think Lithium is the future, the price is going to come down, however, I do think Autosleeper moving to Lithium before increasing the capacity to charge at the rate lithium can take is nuts, and for people who predominately use EHU, it is a waste of money.

if its any help I have just finished a project on my kingham  to upgrade to lithium and the advantage of it  as I like using cl sites without hook up (which incidentally with electric prices soaring most sites will charge more!!) and the results are superb to the point it makes the basic system look ok for occasional use, I have used all renolgy equipment and probably cost about £900 in total, sergeant were very helpful with wiring diagrams and especially the exact wiring of a relay to isolate the vehicle battery when driving so that charging of the lithium battery is done via the dc to dc charger ,having spent a few days at leisure really enjoying the conversion the results perfect for my use ( incidentally I do have a 200 watt solar array and votronic controller to feed in which was already fitted before this conversion) so I can deffo recommend for anybody that feels confident to do the work and enjoys being off grid

Before making comparisons you have to make sure you use correct values of parameters

Due to higher depth of discharge for Lithium batteries a 100Ah SLA is equal to 68Ah LiFePo or conversely a 100Ah LiFePo4 is equivalent to around 150Ah SLA, who has the space for a 150Ah SLA and think about the weight.

LiFePo4 batteries are half the weight of the equivalent SLA

SLA have a charge cycle to 80% capacity count of 300 vs 2200 of LifePo4

You could expect to replace the SLA 5-7 times in the life of a LiFePo4

So this makes the value of LiFePo4 much better than SLA.


EXCEPT.....

Who is going to keep their motorhome for the life of 5 batteries?

We rarely go on hookup and have been managing well with the standard battery/charger and alternator but at some time in the near future the battery will need replacement (4years old) and I’m thinking lithium.I’ve had a quote from an installer with all the extras that they say is needed and I just wondered if any one has just dropped a battery in and if extras are needed can be added later

I don’t think I have the technical knowledge to do the electrical mods myself but nice to see someone happy with lithiums

treetops wrote:if its any help I have just finished a project on my kingham  to upgrade to lithium and the advantage of it  as I like using cl sites without hook up (which incidentally with electric prices soaring most sites will charge more!!) and the results are superb to the point it makes the basic system look ok for occasional use, I have used all renolgy equipment and probably cost about £900 in total, sergeant were very helpful with wiring diagrams and especially the exact wiring of a relay to isolate the vehicle battery when driving so that charging of the lithium battery is done via the dc to dc charger ,having spent a few days at leisure really enjoying the conversion the results perfect for my use ( incidentally I do have a 200 watt solar array and votronic controller to feed in which was already fitted before this conversion) so I can deffo recommend for anybody that feels confident to do the work and enjoys being off grid

The “drop-in” replacements are called such because they incorporate battery management board that isolate the charging requirements from the charge source. Give them power at the terminals and the BMS takes care of it. 

These however are optimised for starter duties and I don’t know how applicable that would be for a leisure battery

These parameters would be software based so no reason why they could not be reprogrammed.

HairyFool wrote:


EXCEPT.....

Who is going to keep their motorhome for the life of 5 batteries?

Its an idea; I would be motor homing till aged 95, the van would then be 35 and banned from every road in Europe. Like many aspects of life at my age, there is no time left to get a return on investment!

Simplicity, every time.
Anything Sargent avoid at all costs
Lithium will not get cheaper, demand for lithium is going through the roof for all sorts of things, esp elec cars.
Cost of average motorhome, let's say £30000 or so
Cost of SLA battery, circa £100 so 100/30000 = 0.00333
1/5 yrs, £20, irrelevant IMHO!!
110Ah SLA and circa 100w solar, all we've needed anywhere we've been!

Alan WH wrote:We rarely go on hookup and have been managing well with the standard battery/charger and alternator but at some time in the near future the battery will need replacement (4years old) and I’m thinking lithium.I’ve had a quote from an installer with all the extras that they say is needed and I just wondered if any one has just dropped a battery in and if extras are needed can be added later

My leisure battery failed recently, it was just under 3 years old but I suspect the premature failure was because it wasn’t looked after at the dealers before I bought the van. A 110ah replacement cost just over £100 delivered and I expect to get at least 4 years out of it.
Lithium is definitely the future and if I was installing a complete new system (and had the budget!) then I would also go the way treetops has but on a 3 year old van a simple lead acid replacement that has served me 100% satisfactorily to date was the easy choice.

Kevinktwo wrote:EXCEPT.....

“Who is going to keep their motorhome for the life of 5 batteries?”
The batteries can come across to your next Motorhome.

Wouldn’t that leave a big battery sized hole where you removed it from that would need filling?

Assuming the next MH can accept Lithium Batteries??????

IanH wrote:Assuming the next MH can accept Lithium Batteries??????

You are two steps ahead of me Ian!!

treetops wrote:if its any help I have just finished a project on my kingham  to upgrade to lithium and the advantage of it  as I like using cl sites without hook up (which incidentally with electric prices soaring most sites will charge more!!) and the results are superb to the point it makes the basic system look ok for occasional use, I have used all renolgy equipment and probably cost about £900 in total, sergeant were very helpful with wiring diagrams and especially the exact wiring of a relay to isolate the vehicle battery when driving so that charging of the lithium battery is done via the dc to dc charger ,having spent a few days at leisure really enjoying the conversion the results perfect for my use ( incidentally I do have a 200 watt solar array and votronic controller to feed in which was already fitted before this conversion) so I can deffo recommend for anybody that feels confident to do the work and enjoys being off grid

Hello, I have just purchased a 2018 Kingham and wish to upgrade , any pointers welcome, what system have you fitted amp hrs etc and did it include an inverter?

Lithium batteries should never be regarded as drop in replacements.

Quite apart from the points already mentioned (inc. upgrading cabling, possibly alternator etc.) there is the fire and toxic fumes issue. LiFEPo4 are generally regarded as less prone to thermal runaway than some other lithium types but it can still happen. I can live with the risks of a lead acid battery in a habitation area but Lithium types really need to installed “outside” where there is less immediate danger from fire and the cocktail of toxic fumes that can be liberated.

Note also that some insurers would regard such a significant change to the vehicle spec as an unauthorised or notifiable modification.

It is telling that the maritime standards organisations that I deal with are still trying to formulate suitable standards and guidance for shipping and pleasure craft but the industry is moving faster than they can for obvious reasons (I.e. the imposition of ev’s) and there is simply not enough experience around yet. The people that say Lithium is safe are the people selling them!

Lead acid batteries are no safer than Lithium phosphate batteries when used properly. Charging a lead acid battery gives off hydrogen which is much more inflamable and likely to caue an explosion than a LiPo battery is to catch fire. There are more explosions caused by hydrogen from charging lead acid based batteris than fires from lithium phosphate based batteries. The lifetime and future of 12v batteris is Lithium based batteries as the price is already starting to drop and the lifetime costs are already lower. The problem is that LiPo batteries are not compatable with lead based battery chargers which gives us problem to those of us who wanting to upgrade. The problem is that you can't charge a lithium based battery with a lead acid based battery charge.