Technical Upgrading my leisure batteries to LiFePO4

[Nenagh52]

So we are heading over to France next week for a week with the van and I want to look at getting, for pricing reasons, a few LiFePO4 leisure batteries [LB] to replace the existing AGM one.
Am thinking 2 by 200 Amp
My existing LB charger [Schaudt booster 121525] is only suitable for Gel/AGM/Li so I will need to change it.
So looking for
1: any insights on the idea itself
2: recommendations for a suitable LiFePO4 charger

I presume my existing on board mains chargers will not need replacing
[which I assume charges the starter battery directly as well as the LBs, but through the schaudt?

I also have a PV panel, with its "gizmo" in with all the other electrical kit
Thanks as always

 

[theoneandonly]

LiFePO4 is a game changer for off grid if you are properly set up. If you always use ehu and saving pennies its not for you. Fisrtly dont believe that Li is a drop in replacement fo Pb. A b2b is necessity, why ? you are risking alternator damage and throwing away one of the advantages of Li that is quick charging. If you have a b2b you need to dissable any slit charge system. Stirling and Votronics are good suppliers. Votronics make a number of sizes from 30A 45A and above. I bought a 30A one with the ability to add a second for 60 at another time. Both are suitable for Li. I also use Votronic mmpt solar controlers. Cheap controler wont be ready for Li. I use Votronics as they can trickle charge the SB. Alternative quality controllers are Victron. If old or a british van the wiring is also likely to need upgrading. All in all not cheap, or quick but my instalation has been well worth it.
The precice mix of solar size of b2b depends on your style of camping moving daily or stationary. Note i havent even mentioned a mains charger. Edit i dont use one. The original cbe is acceptable switched to Gel, doesnt fully charge.

 

[Nenagh52]

LiFePO4 is a game changer for off grid if you are properly set up. If you always use ehu and saving pennies its not for you. Fisrtly dont believe that Li is a drop in replacement fo Pb. A b2b is necessity, why ? you are risking alternator damage and throwing away one of the advantages of Li that is quick charging. If you have a b2b you need to dissable any slit charge system. Stirling and Votronics are good suppliers. Votronics make a number of sizes from 30A 45A and above. I bought a 30A one with the ability to add a second for 60 at another time. Both are suitable for Li. I also use Votronic mmpt solar controlers. Cheap controler wont be ready for Li. I use Votronics as they can trickle charge the SB. Alternative quality controllers are Victron. If old or a british van the wiring is also likely to need upgrading. All in all not cheap, or quick but my instalation has been well worth it.
The precice mix of solar size of b2b depends on your style of camping moving daily or stationary. Note i havent even mentioned a mains charger. Edit i dont use one. The original cbe is acceptable switched to Gel, doesnt fully charge.

the Van is May 2021 build: Fiat Ducato.

Thanks for this, much to consider.
In the meantime:
what is a b2b and cbe.
.
Just looking at the Lithium-ion and LiFePO4 batteries online they are all c 21.7 cms or higher.
The AGM that is under the seat is 19 cms and is a tight fit from the front so I would need to locate them elsewhere.
Bearing in mind all that is posted above in your reply around LiFePO4 and the costs etc
looking at this rig I am considering a " standalone " LiFePO4 setup rather than invest in Lithium-ion which are compatible with the existing booster
.
Amazon product ASIN B0BW8PZW3Zwhich comes with a 10A mains and battery fed charger, what would the mains piece Amp draw be on an 12V inverter?
or this one
Amazon product ASIN B0BB6B2NCSwhich has a 20A charger
Thanks as always

 

[theoneandonly]

B2B battery to battery charger, an effective safe means of charging sb and lb. Should be a requirement if you have a smart alternator.
CBE is just a brand of electrical control equipment simular to schaut or sargent (italian, german, english)

 

[Nenagh52]

B2B battery to battery charger, an effective safe means of charging sb and lb. Should be a requirement if you have a smart alternator.
CBE is just a brand of electrical control equipment simular to schaut or sargent (italian, german, english)

Thanks, your reply came in while I was editing my reply to your first reply

 

[HughJampton]

The Schaudt WA121525 "booster" (it's a BtoB charger) should be compatible with LiFeP04 batteries on its Li setting (it's a straight 14.4V charging regime).

There are a good few (reputable) LiFeP04 batteries of the same dimensions as standard AGM batteries (i.e. 190mm high) but there are also "underseat" batteries of larger capacity and the appropriate dimensions from the main suppliers.

 

[Nenagh52]

The Schaudt WA121525 "booster" (it's a BtoB charger) should be compatible with LiFeP04 batteries on its Li setting (it's a straight 14.4V charging regime).

There are a good few (reputable) LiFeP04 batteries of the same dimensions as standard AGM batteries (i.e. 190mm high) but there are also "underseat" batteries of larger capacity and the appropriate dimensions from the main suppliers.

Thank you, can you provide some names so as I can explore them

 

[HughJampton]

Try KSEnergy, Ecotree, Fogstar, Roadpro - there are many more.

 

[Communicator]

So we are heading over to France next week for a week with the van and I want to look at getting, for pricing reasons, a few LiFePO4 leisure batteries [LB] to replace the existing AGM one.
Am thinking 2 by 200 Amp
My existing LB charger [Schaudt booster 121525] is only suitable for Gel/AGM/Li so I will need to change it.
So looking for
1: any insights on the idea itself
2: recommendations for a suitable LiFePO4 charger

I presume my existing on board mains chargers will not need replacing
[which I assume charges the starter battery directly as well as the LBs, but through the schaudt?

I also have a PV panel, with its "gizmo" in with all the other electrical kit
Thanks as always

1. Consider what you want from lithium batteries.

2. What is the capacity in Ah (Ampere hours) of your existing AGM battery? (Battery capacity is measured in Ampere hours, not Amperes (A) which is a measurement of current flow).

3. Normal advice is not to discharge a lead acid below 50% depth of discharge (DoD). So if you have a nominal 100Ah AGM battery, which is a lead acid battery, there is only about 50Ah of useable capacity. You can discharge further, but battery life will be shortened.

4. Lithium batteries have a much longer, perhaps 10 times the charge/discharge cycle life when taken to 80% DoD. This means that a 200Ah lithium battery will have more than 3 times the useable capacity of a 100Ah lead acid battery. Do you really need over six times you probable present useable battery capacity.

5. Lead acid batterries generally have a maximum advised charge rate of C/10 (capacity in Ah/10), so 10A for a 100Ah battery. At this rate, and allowing for the losses in the battery, it would take about six hours to recharge a !00Ah lead acid battery that had been discharged to the recommended 50% DoD. Another advantage of lithium batteries is the recharge rate of C/4, or 50A for a single 200Ah battery. This is double the rated output of the existing Schaudt 121525 "booster" or B2B, but a recharge time of less than 4 hours seems possible, with a larger B2B.

6. Your Schaudt Electroblok, is probably fused at 50A on the habitation battery side. It would not be sensible to connect a larger B2B than the existing unit via the EBL. A larger B2B would have to be connected directly to the batteries via suitable fuses close to the batteries. Extensive rewiring with thicker cables would be needed.

7. Is the alternator suitable for the increased load when recharging the lithium batteries? OK for the existing B2B, but if going higher, it may need changing for a model with a higher rating. I have read that alternator ratings are for maximum, and not sustained current.

8. The existing mains charger will not fully charge lithium batteries unless it has a lithium profile, but I have seen recommendations for storing lithium batteries at below 100% state of charge. Possibly rated at 16A it would take over 10 hours flat out to recharge one 200Ah battery from 80% DoD. It may not survive that duty. There is a facility in the Electroblok for providing a low rate charge to the starter battery, but this depends on a "Mains ON" signal from the Schaudt charger.

9. Solar panels are a useful way of charging lithium batteries, but in the you will need as large an area as possinle with an MPPT (maximum power point tracking) regulator for maximum gain. No details were submitted.

10. For prices about £600 upwards for one 200Ah lithium battery in UK.

11. Fom your use of the abbreviation "A" to denote battery capacity, the term "gizmo" for your solar regulator, and your unfamiliarity with the common abbreviation, B2B, it seems that your electrical knowledge is limited. Perhaps you should seek the advice of a competant installation technician. A charged battery contains a lot of energy, and while 12V is in itself not dangerous, the possible high currents flowing can cause fires, and personal injury.

 

[HughJampton]

I've fairly recently replaced 2x95Ah AGM leisure batteries with a single 110AH LiFePo4 battery.

The change was made largely for one reason, weight saving (not far of 40kg for similar useable capacity) and the timing was dictated by the age of the existing AGM batteries (though at 5 years they might have some life left yet!).

I had already fitted 120W of solar with a lithium-capable MPPT charge, so that simply needed a battery type change on the Votronic controller.

The internal mains charger on the EBL was used initially on Gel setting, but in the end I fitted an external Victron 15A charger with lithium and user-programmable settings, and disabled the internal charger. Hymer luckily provide a 230V connection for a second charger, and it was easy to use that.

Hymer also use 16mm² wiring for all the main battery cabling, so it is man enough to take Li-oriented changes (be aware this isn't the case for all converter's wiring).

All the above seemed functional, but I still wasn't happy with the battery BMS providing some protection against over-voltage, so I've recently fitted the aformentioned WA121525 (which with the appropriately-sized OE cabling wasn't the most difficult of jobs.

I've lost a couple of kg of the original weight saving through the new kit, but the final situation is still significant at around 38kg (you don't acknowledge the weight of a lead-acid battery until you get to lift one again).

We're not heavy users of 12V, though we are regularly off-grid for some days, and the bluetooth readout of SoC is very reassuring. The 110AH capacity is ample for us, but probably not for anyone with heavy use who is static for some time. I paid for both bluetooth and heating on the battery, as we use the 'van the year round, and we have known freezing temperatures onboard.

 

[Nenagh52]

Thank you all for your comprehensive and helpful contributions.
I contacted each of the ones listed in post 8 above and one of them manufactures and sells such batteries 35 kms away from where I live.
So I will deal with them, leave some money in the local economy and be advised by them.

 

[HughJampton]

Fair enough, but I'd echo Communicator's post above.

They aren't really a drop-in replacement (though under certain circumstances they can almost be, with reduced efficiency and dependent on the particular battery and existing kit - an awful lot of which is not really up to the job).

If you aren't clear what you're doing, there are some significant pitfalls, and in those circumstances it is best left to the professionals.

 

[theoneandonly]

Fair enough, but I'd echo Communicator's post above.

They aren't really a drop-in replacement (though under certain circumstances they can almost be, with reduced efficiency and dependent on the particular battery and existing kit - an awful lot of which is not really up to the job).

If you aren't clear what you're doing, there are some significant pitfalls, and in those circumstances it is best left to the professionals.

I can only repeat my first statement and agree with Hughjampton and communicator they are not drop in replacements.