Clayton LPS again - another question

[d8smt]

So I still haven't got round to decommissioning the Clayton and putting in a conventional system, will do it at the end of summer. So far it's behaving tbh, and I've now got the solar working in it as well, with the random current strain having somehow resolved itself.

So the question is - has anyone tried charging an additional battery (lithium) from it? I know it's an option on the LPS2, but it would make it so much easier with a battery capacity increase. I'm thinking of rather than using something like a jackery, somehow skunk-worksing in a circuit where the LPS can both charge and draw from an external battery? Would be interested if anything has tried.
thx all

 

[Dellmassive]

I've done similar.

Use a dc-dc charger from the engine bay to a 12v lithium LB.

Then connect the LPS to that LB.

...


The engine charges the LB and will act as a buffer battery before the LPS.

The LPS will then draw from the LB and internal battery.

But it means the LPS starter connection needs mining over to the LB.


I show my LPS running this way in my thread on it.

 

[Dellmassive]

More info.

Thread '[Guide] Clayton LPS II 2500 - 1kWh (leisure battery + Inverter) -- How I Done It --'

2 Jan 2024

[Guide] Clayton LPS II 2500 - 1kWh (leisure battery + Inverter) -- How I Done It -- (@Dellmassive)

its finally happened,

I've dipped my toes into the dark side of 12v leisure electrics.



The Clayton LPS II - the All In One ( 12v lifepo4 battery, dc-dc charger, 240v inverter, solar MPPT, + more)


+++

i have the 2500w (inverter) 1kWh (100ah lifepo4 battery) version. ie LPSII2500-1kwh

+++



+++







now this is going to be an interesting thread. . . and ill bring you along with me.


the original plan for the "BUS" - our other T6...

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• Forum: Electrics, Lighting, ICE, Security

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[d8smt]

So I still haven't got round to decommissioning the Clayton and putting in a conventional system, will do it at the end of summer. So far it's behaving tbh, and I've now got the solar working in it as well, with the random current strain having somehow resolved itself.

So the question is - has anyone tried charging an additional battery (lithium) from it? I know it's an option on the LPS2, but it would make it so much easier with a battery capacity increase. I'm thinking of rather than using something like a jackery, somehow skunk-worksing in a circuit where the LPS can both charge and draw from an external battery? Would be interested if anything has tried.
thx all

@Dellmassive that's brilliant, thank you & much appreciated

 

[d8smt]

@Dellmassive that's brilliant, thank you & much appreciated

@Dellmassive - another quick question for you on this if you don't mind.... so I see your logic in using the lithium battery as a buffer to the LPS.
I'm not as well up on the auto electrics side of things as I ought to be, but is there any reason not to use the extra lithium battery in a similar way to the solar/fast charge option, by linking the lithium battery to the DC out terminals of the LPS? I'm guessing you'd need a split charge unit/dc-to-dc to split the current from the van both into the LPS and also into the lithium battery, but this way I could isolate/take out the lithium battery when it's not needed for use elsewhere. Would this arrangement work?

 

[Mateus]

Dont suppose you know if your solution works for the lps1 @Dellmassive? Would be great to get a bit more juice… thanks

 

[roadtripper]

@Dellmassive - another quick question for you on this if you don't mind.... so I see your logic in using the lithium battery as a buffer to the LPS.
I'm not as well up on the auto electrics side of things as I ought to be, but is there any reason not to use the extra lithium battery in a similar way to the solar/fast charge option, by linking the lithium battery to the DC out terminals of the LPS? I'm guessing you'd need a split charge unit/dc-to-dc to split the current from the van both into the LPS and also into the lithium battery, but this way I could isolate/take out the lithium battery when it's not needed for use elsewhere. Would this arrangement work?

View attachment 287816

That arrangement is likely to cause issues as you are effectively parallel connecting the LPS internal battery and the external lithium - and then you are trying to parallel charge them with the LPS charger and an external charger at the same time.

If you want portability maybe build the external lithium into a tool box with the Victron to make a battery box like @Dellmassive does. If you have 50A Anderson connectors throughout you can either plug the LPS directly into the van or daisy chasing it through the battery box.

Only thing you might need is an additional connector or switch for the D+ signal to the LPS when the buffer battery is in place.

 

[roadtripper]

Dont suppose you know if your solution works for the lps1 @Dellmassive? Would be great to get a bit more juice… thanks

It's a technique that should work for most things, you are just replacing the 12v feed from the van with a 12v feed from the buffer battery.

The only thing you need to think through is what you do with the D+/engine running signal. If you use a buffer battery you do not want that to be an actual engine run signal, or when the engine is off it will not draw from the buffer battery. Most likely just connect to the positive of the buffer battery.

It would be worth checking in your LPS manual what the low voltage cutoff is on its input and comparing that to the battery you intend to use. What you don't want is the LPS draining the buffer battery stone dead every time and shortening the buffer battery lifespan.

 

[Mateus]

wow, thanks for the comprehensive reply! will have a think