Lithium batteries cannot just drop in and replace lead batteries can they?

[wfdTamar]

If you're hesitant about lithium (the cost or if your van can handle it) have a look at the lead carbon gel from Alpha Batteries. My Hymer has an EBL 99 which can only take lead acid or gel and I replaced a 100Ah Yuasa LR-36 EFB (which had been a good battery, but only 50Ah usable) with the 110Ah lead carbon gel, so 88Ah usable (and still gets 750 cycles at that rate). The one drawback is the weight (twice a lithium).

I had to cut the plywood base under the seat the leisure battery sits on and convert the connections to mate terminations. It just fits (being higher than normal).

 

[nickq]

I have no problem with my DS300 since fitting a B2B. I separated the leisure and engine batteries with a new relay at +B1. The DS unit and its functions continue to be powered by the leisure battery which is getting a good direct charge from the B2B. The original relay simply joined the 2 batteries which meant the DS was powered by whichever battery had the highest voltage, my modifications have made no difference to the fridge operation on 12V.

Yes thanks, I read through your posts, makes sense. I don't have D+ at the services battery so running a new cable from starter to services via a B2B there isn't viable. I'll call vanbitz later and see what they say.

 

[Pausim]

Yes thanks, I read through your posts, makes sense. I don't have D+ at the services battery so running a new cable from starter to services via a B2B there isn't viable. I'll call vanbitz later and see what they say.

I am sure Vanbitz will have some good ideas. I would have thought you could use +B2 and - at the DS300 and disabling the relay by whatever method should not interfere with the fridge operation. It will be interesting to see what they suggest.

 

[MisterB]

i used to get a few D+'s at school ...... Im sure some teachers thought id never amount to anything, yet here i am, lay on the sofa, cup of coffee at hand, reading and writing on the laptop, dreaming of future trips, how wrong they were .....

 

[Pedro Pallent]

The Answer is: YES!!! no additional components are required
That's not me saying that. That's from the KS Energy website: https://www.ksenergy.co.uk/lithium-leisure-battery-drop-in-replacement

In which they go into a lot of detail as to why this is the case. Now I'm no battery expert, but I would love this to be true. I have a single 80ah Gel battery which is completely dead and I've been looking into getting a replacement and wouldn't mind paying the extra for Lithium. I have a Victron solar charger which can handle Lithium and a Schaudt Booster 121525 B2B which I think also can. However the mains charger (Schaudt Elektroblock EBL 241-2) only supports lead acid or lead gel and I would like to not have to replace this if possible.

So, I'd be grateful for any views on the feasibility of just replacing my dead gel with a lithium battery without changing anything else and whether anyone has had experience of doing this. Many thanks in advance.

I have a KS 155A lithium battery in my motorhome and so far it has done all it says on the tin. The Bluetooth app needs to be less cluttered but gives out data for you to peruse. It has been installed approximately 4 months now, had to change the solar regulator to MTTP, but due to engine being a Euro 6, evidently the alternator is a smart one, and don’t need a B2B.

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[bigtwin]

As I understand it the wiring will work with the split charge relay because there is a built in limit to the rate of charge.

What determines the ‘built in limit’? The system should be designed to accommodate the maximum delivery capability of the energy source. That is part of the design process for sizing cables (and hence fuses). It should not be designed for what may, or may not, be connected downstream. If the vehicle is fitted with a, say, 110A alternator then the cabling/fusing should be rated accordingly and it shouldn’t matter a jot whether it’s a Lead acid battery, a lithium battery, or a short circuit that’s on the end of the cable.

But once you by-pass the split charger with a B2B and insert lithium batteries which have lower resistance than lead acid that increases the current beyond the capacity of the existing wiring.

The cabling should be capable of handling the maximum current capable of being delivered by the energy source (the alternator) so it’s not possible to exceed the capacity of the wiring.

That is not the converter's fault if the whole thing melts because you have changed their design.

It absolutely is the converter’s fault if they do not fit appropriately sized cables. And to think that these vehicles are NCC approved.

The wiring was never desgined to handle the high currents a Lithium can take.

Why not? It’s good design practice. The issue isn’t that the system was never designed to handle the high currents lithium can take, the issue is that the wiring isn’t designed to handle the currents that the power source (the alternator) can deliver.

Most German vans you will be OK as the split charge wiring is normally 16mm sq, it will get hot and you will get a bit of a volt drop but it won't go up in smoke.

Precisely, the cabling has been sized appropriately!

British built vans with their pathetically undersized wiring is a different case.

A disgraceful state of affairs and, of course, NCC approved.

What I am saying is a Lithium battery is a sponge, and if it’s maximum charge rate is 100amps

The problem arises not because of the high charge acceptance rate of lithium but rather the undersized cables that cannot accept the maximum current capable of being generated by the alternator.

and you have a ’standard’ split charge system which is a cheapo relay costing a quid or so putting the engine battery and the leisure battery in parallel when the engine starts, connected by a long wire (too long) that’s about as thick as a boot lace, then the ‘sponge’ will be looking for a charge of, or up too 100 amps.

If the alternator is capable of delivering 100 amps (irrespective of what the load is, be that a lead acid battery, a lithium battery, or a short circuit) then the cabling/relay should be capable of handling that current. Anything else amounts to bad practice.

Most split charge fuses are rated at 20 - 25 amp.

Given that the fuse is there to protect the cable, that rather suggests that the cable is undersized for the delivery capability of the alternator. Who sanctions these designs?

The BMS ((Battery Management System) will protect the battery from dangerous input/output requests but cannot detect that a 30 amp automotive relay designed to blow air horns or fog lights is getting dangerously hot

Indeed, but that isn’t the function/fault of the BMS. The fundamental issue is that converters are adopting unsafe design practices by fitting undersized cables.

Split charge systems have always been shit, and now lithium batteries are available split charge systems are dangerous shit.

I think that it’s true to say that the adoption of lithiums is highlighting the poor design practices of converters. It isn’t, fundamentally, an issue with lithiums but rather an issue with poor (unsafe) existing design practices that are being highlighted by the different characteristics of lithiums.

Ian

 

[jongood]

Victron make their buck boost DC-DC chargers up to 100 amp

Van Bitz stock them

Buck-Boost DC-DC Converter 25A / 50A / 100A - Victron Energy

Charge a 12/24V service battery in vehicles with an intelligent dynamo using the Buck-Boost DC-DC Converter. Find a dealer near you.

www.victronenergy.com

So if You have a separate alternator just for the leisure battery (like me) can you you run a buck booster from alternator feed directly to a LiFePo4 battery bank?

 

[Paullo]

Wow, so it doesn't seem to be as easy as I hoped it would be, or as KS Energy would have us believe. But you've all given good advice and there's lots to think about. Some of you have just dropped in lithium and seem to have no problems. Others, including some of the more expert contributors caution against this. Some have mentioned getting the ebl upgraded by Apuljack to accommodate lithium (at a cost of £104). And of course I could just forget about lithium altogether and go for the simplest solution which would be to stick with lead gel including the suggestion of lead carbon gel which seems interesting. Lots to think about.

 

[POH]

The wiring was never desgined to handle the high currents a Lithium can take.
Most German vans you will be OK as the split charge wiring is normally 16mm sq, it will get hot and you will get a bit of a volt drop but it won't go up in smoke.
British built vans with their pathetically undersized wiring is a different case.

Lenny what about French ones ie Pilote

 

[Lenny HB]

Lenny what about French ones ie Pilote

Some of the pics I've seen on here they look like somewhere in between I think someone mentioned the other week they were 10mm sq. So still a bit small.

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[eddie]

I think that it’s true to say that the adoption of lithiums is highlighting the poor design practices of converters. It isn’t, fundamentally, an issue with lithiums but rather an issue with poor (unsafe) existing design practices that are being highlighted by the different characteristics of lithiums.

Ian

Your wrong, I’ve been saying it’s a shit way to do it for thirty years, written articles the lot

Of course not all converters cut corners and do it cheap.

 

[eddie]

I have a KS 155A lithium battery in my motorhome and so far it has done all it says on the tin. The Bluetooth app needs to be less cluttered but gives out data for you to peruse. It has been installed approximately 4 months now, had to change the solar regulator to MTTP, but due to engine being a Euro 6, evidently the alternator is a smart one, and don’t need a B2B.

You’ll have a B2B and you’ve upgraded your solar regulator so again drop in, if the right equipment is used!

 

[bigtwin]

Your wrong

How so, can you expand?

I’ve been saying it’s a shit way to do it for thirty years,

What’s a shit way of doing it; undersized cables? split charge systems?

Of course not all converters cut corners and do it cheap.

Agreed, but far too many nonetheless.

Ian

 

[eddie]

You said lithiums are highlighting the issues, whereas anyone who understands batteries and DC-DC charging knows it’s a poor way to go about it.

Your engine battery is very close to the alternator and connected to the alternator with a big thick short cable. The leisure battery where ever there is space, and connected via a skinny little cable sometimes several meters long and switched with a cheap old relay

Whats not to like

 

[eddie]

Split Charging - VanBitz

So what is a split charge relay?

www.vanbitz.com

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[jongood]

Split Charging - VanBitz

So what is a split charge relay?

www.vanbitz.com

This video has been doing the rounds for a while. I don't dispute that alternators can overheat but I find this video disingenuous - surprising for a reputable company - The alternator fails at low RPM, the video stating that it was running at 1500rpm but this would not be so when connected to a vehicle engine because the crank pulley is about twice the size of the alternator pulley, so in a vehicle running at 1500rpm the alternator would be running at 3000rpm which they had already demonstrated was fine. We also didnt get to see how long they ran it for.

I also wonder why they were using a battery which had a BMS but had disabled it?

 

[eddie]

This video has been doing the rounds for a while. I don't dispute that alternators can overheat but I find this video disingenuous - surprising for a reputable company - The alternator fails at low RPM, the video stating that it was running at 1500rpm but this would not be so when connected to a vehicle engine because the crank pulley is about twice the size of the alternator pulley, so in a vehicle running at 1500rpm the alternator would be running at 3000rpm which they had already demonstrated was fine. We also didnt get to see how long they ran it for.

I also wonder why they were using a battery which had a BMS but had disabled it?

I do tend to agree about the video, I uploaded it years ago (when I was working)main to show people potential issues

I posted the link for the descriptions of different ways for DC-DC charging as Bigtwin thinks he’s discovered a design flaw in motorhomes which actually has been known for years

 

[Garry - June]

I have 2x KS Energy 155ah Lithiums which I fitted last summer.. apart from changing the settings on my Votronic solar controllers to Lithium settings left everything else as was and the set up has been working brilliantly since, so yes they are simple "drop ins" ... I and a few others have been very critical of the Victron Youtube video showing the alternator overheating...you would not likely encounter those test conditions in real life and in my opinion is its geared to increasing sales of their B2B's as much as anything else... in real life I have had no problems with my alternator and the Lithiums.. the android app monitoring on the batteries is brilliant and very useful.. most of my charging is done via solar as once set up we don't tend to move much so a B2B is not much use to us.. the addition of an Dometic RCD Compressor fridge in place of the old 3 way alongside the Lithiums has been a total game changer as well.. I am just returning from 3 months in Portugal.. not needed EHU since the beginning of March .

 

[bigtwin]

You said lithiums are highlighting the issues, whereas anyone who understands batteries and DC-DC charging knows it’s a poor way to go about it.

I have no issues with using better charging methods. The point I was making is that lithiums aren’t the problem; the problem is a badly designed split charging system.

Your engine battery is very close to the alternator and connected to the alternator with a big thick short cable. The leisure battery where ever there is space, and connected via a skinny little cable sometimes several meters long and switched with a cheap old relay

There’s nothing wrong with skinny long cables provided that they’re rated for the maximum current delivery capability of the power source.
Since you mention long skinny cables, they can be part of the current limiting solution for lithiums. There is nothing complicated to go wrong with a bit of resistive wire (provided it is rated appropriately - you might be picking up on a bit of a theme here ).

I posted the link for the descriptions of different ways for DC-DC charging as Bigtwin thinks he’s discovered a design flaw in motorhomes which actually has been known for years

I don’t think that I’ve discovered anything (and wasn’t implying such) I was simply pointing out to those who are keen to point the finger of blame towards lithium that they are looking at the symptom and not the root cause.

Ian

 

[eddie]

I have no issues with using better charging methods. The point I was making is that lithiums aren’t the problem; the problem is a badly designed split charging system.



There’s nothing wrong with skinny long cables provided that they’re rated for the maximum current delivery capability of the power source.
Since you mention long skinny cables, they can be part of the current limiting solution for lithiums. There is nothing complicated to go wrong with a bit of resistive wire (provided it is rated appropriately - you might be picking up on a bit of a theme here ).



I don’t think that I’ve discovered anything (and wasn’t implying such) I was simply pointing out to those who are keen to point the finger of blame towards lithium that they are looking at the symptom and not the root cause.

Ian

Well whatever you ‘think’ a simple parallel connection between differing battery types, via a simple electro mechanical relay is a poor way to charge a secondary battery(s)

Add to that that the wiring normally used is inadequate and you end up with a cheap but poor solution

For most people that normally have hook up they’ll never notice, and for the odd Summer rally they attend their 12 volt requirements are negligible and their solar copes.

So I ‘think’ we are agreeing

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[AshVanBitz]

The problem starts with the converters. They have specific employees whose job is to go out and purchase items that will just about work for their intended purpose but for as little money possible! Motorhomes are designed by people that don’t actually use them and they are made to look as pretty as possible with additional LED lighting under the worktops, glossy cupboard doors, TV’s that pop up from behind the bench seats, etc. They will argue until they are blue in the face that everything if fully functional and adequate as the primary design is to be used whilst on EHU. Even the new motorhomes that are “Lithium ready” are exactly the same and the components installed will do the job but with limitations. For most motorhome users it will be absolutely perfect and they will not have any issues but for the more experienced/extreme of us who use their vehicle to its maximum potential, it can be very limiting and that is why more and more owners are taking it upon themselves to enhance the equipment that is lacking.

 

[WillysMB]

The problem starts with the converters. They has specific employees whose job is to go out and purchase items that will just about work for their intended purpose but for as little money possible! Motorhomes are designed by people that don’t actually use them and they are made to look as pretty as possible with additional LED lighting under the worktops, glossy cupboard doors, TV’s that pop up from behind the bench seats, etc. They will argue until they are blue in the face that everything if fully functional and adequate as the primary design is to be used whilst on EHU. Even the new motorhomes that are “Lithium ready” are exactly the same and the components installed will do the job but with limitations. For most motorhome users it will be absolutely perfect and they will not have any issues but for the more experienced/extreme of us who use their vehicle to its maximum potential, it can be very limiting and that is why more and more owners are taking it upon themselves to enhance the equipment that is lacking.

It must be said that this thread is proving to be quite enlightening ..Ill have to pick your brains in person
when our van arrives and is having some work done on it .

 

[Pausim]

There’s nothing wrong with skinny long cables provided that they’re rated for the maximum current delivery capability of the power source.
Since you mention long skinny cables, they can be part of the current limiting solution for lithiums. There is nothing complicated to go wrong with a bit of resistive wire (provided it is rated appropriately - you might be picking up on a bit of a theme here ).

I don’t like the idea of relying on long skinny cables to limit power, especially as the alternator power source can be hundreds of amps. Resistance = heat and the idea of wires getting warm doesn’t appeal to me.

 

[bigtwin]

I don’t like the idea of relying on long skinny cables to limit power, especially as the alternator power source can be hundreds of amps. Resistance = heat and the idea of wires getting warm doesn’t appeal to me.

If you take out the emotive use of the term ‘skinny’ and use ‘appropriately rated’ instead, where’s the issue? Nobody would advocate an undersized cable, that would be foolish.

I’d love to have an alternator capable of delivering hundreds of amps and if I did I’d ensure that the alternator cable was sized accordingly. That is the whole essence of my previous responses that the fundamental issue is that the cabling on many installs are undersized; it is not a lithium issue, it’s a flawed installation issue.

Cables, even appropriately rated ones, will get warm as currents increase; it’s not, per se, an indicator of a problem.

Ian

 

[Lenny HB]

I’d love to have an alternator capable of delivering hundreds of amps and if I did I’d ensure that the alternator cable was sized accordingly. That is the whole essence of my previous responses that the fundamental issue is that the cabling on many installs are undersized; it is not a lithium issue, it’s a flawed installation issue.

Most Motorhomes are fitted with an uprated Alternator 160 to 180 amps is quite common.

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[Langtoftlad]

For most people that normally have hook up they’ll never notice, and for the odd Summer rally they attend their 12 volt requirements are negligible and their solar copes.

That'd be me then
2x LA batteries, 1x 120w solar
Use sites and attend rallies.
Just about to go home after 4nts at Swaffham and 3nts at a very overcast THS...

 

[Hoovie]

Q

I don’t like the idea of relying on long skinny cables to limit power, especially as the alternator power source can be hundreds of amps. Resistance = heat and the idea of wires getting warm doesn’t appeal to me.

I have read people's arguements about how this is a good design.
I don't get it either and think it is a flawed approach.

And how it is also used as a positive design one day and then a negative feature the next is very contradictory IMO, but each to their own.

 

[bigtwin]

And how it is also used as a positive design one day and then a negative feature the next is very contradictory IMO, but each to their own.

Resistance is resistance. For some scenarios, a design might benefit from low resistance and others it might benefit from a higher resistance.

Resistance, as you know, is a material characteristic that features in various designs. It is neither inherently good nor inherently bad. In lead acid charging it needs to be minimised and in lithium charging it can be beneficial.

Ian

 

[Lenny HB]

lithium charging it can be beneficial.

I don't think so with LA as the voltage across the terminals increases the the charge rate will drop due to increased internal resistance.
With Lithium the voltage stays pretty constant although they are normally charged at 14.2v if the voltage drops to 13.5 they will still suck in 100 amps if they can, so that bit of thin wire is going to get very hot.

 

[nickq]

I am sure Vanbitz will have some good ideas. I would have thought you could use +B2 and - at the DS300 and disabling the relay by whatever method should not interfere with the fridge operation. It will be interesting to see what they suggest.

To close my story on this one. vanbitz were very helpful and the advice is much appreciated. Long story short, best option was to install the B2B near to the leisure battery and routeing new cable under the van, no need to disable the split charge relay if I removed the connections from B1 (binding them together and insulating leaving disconnected and bridged B1 to B2. However this is very specific to my DS300-RA (Rapido) setup and should not be taken as a general solution for any van.

I have decided not to proceed with lithium however because I really wanted the victron B2B with engine on/off sensing so I didn't have to run D+ as I just can't see how to do it with my van without major hassle. However on closer inspection of the manual the Victron needs 100mm clearance above and below for sufficient air flow and they do get very hot with a poor efficiency rating of only 87%. I just don't have this space near my lesiure battery. I know sterling have more efficient fan cooled options but they are also more expensive.

On top of this, the boss says; "you aren't solving a problem you just want lithium" and she's kind of correct.
I do abuse the lead acid when charging all 3 bike batteries off the 1000W inverter and when I make hot milk in my electric frothing heating thingy, but my battery cost £97, it's lasted 2 years so far so I don't care if I kill it soon. I can buy 3 batteries for the cost of the B2B alone (needed the isolating one).

A new van may be on the cards in 2-3 years also so...
Now when I do change the van, if the new one doesn't have lithium already I will most likely go down to vanbitz and have them sort it all out
I just can't make the business case right now.
I've no need for a compressor fridge or electric cooking, the gas works great and my thetford 3 way is brilliant. (normally too cold and I keep turning it down).

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