Lithium upgrade EHU workaround

[tomosllyr]

I know there are plenty of threads on lithium LB upgrades but can't find the answer to my conundrum.

I have a converted camper that we use for 1 or 2 night weekends away, and the occasional 1 week long trip. We live off battery for the smaller trips and use EHU for the longer trips so we can use sockets and the microwave (I don't have an inverter).

I already have a Victron DC-DC charger with a lithium profile. I am booked in to have a solar panel fitted with a Victron MPPT. Once that was done I was hoping to fit a lithium battery (in fact I've already bought it).

But I've realised that my PowerPart PDU has a built in charger for when the EHU is connected which is not lithium compatible.

A conversion company I've spoken to has said that it doesn't matter that the EHU charger is incompatible as long as I use it infrequently and the battery has BMS (which it does).

Is this true?

If not, is there a straightforward way of updating my system so that the EHU can charge a lithium battery?

Or is there a way of turning off the EHU charger when connected to EHU in order to protect the battery and depend on the solar/dc-dc to keep the battery charged?

 

[Dellmassive]

Do you know. Or can't you get the spec of the PowerPart PDU?

Or may be a fixed 13.8v output?.

Or possibly a multistage charger?

Lithium you need to stay under 14.6v.

 

[tomosllyr]

This is the PDU I have:

Converter Power Distribution Unit : Pennine Leisure Supplies

www.plsgroup.co.uk

There is an owner's manual pdf on that website. Very little information available on the manufacturer's website.

 

[Dellmassive]

This is the PDU I have:

Converter Power Distribution Unit : Pennine Leisure Supplies

www.plsgroup.co.uk

There is an owner's manual pdf on that website. Very little information available on the manufacturer's website.

Don't say much....

Might be worth a email to them and ask what the deal is?

 

[EAN]

I’m not familiar with your PDU (and don’t like all in one units) but have in the past modified a similar unit in my friend’s Motorhome.
What I did was open up his PDU, disconnect, remove and discard the internal power supply unit (PSU).
Then I rewired the MCB that originally provided power to the PSU to instead provide the 230Vac feed to an external Victron charger and then wired the new Victron’s charger output back into where the original PSU output connected. I ensured that the Victron charger didn’t supply more current than the original PSU due to not knowing the internals of the PDU (PCB track sizes etc) or the size of some of the external wiring (which was hidden and a complete rats nest anyway). However if you can connect the output of the new charger right back to the leisure battery then you can suitably fuse and size the wires and ignore the PDU; just utilising it’s MCB.
From the manual you linked to the 6A MCB is dedicated to feeding ac power to the internal power supply.
I expect there is also a dc fuse for the output of the power supply, but I couldn’t see that mentioned.
Wouldn’t be difficult for a competent person to update it for you.

 

[tomosllyr]

Don't say much....

Might be worth a email to them and ask what the deal is?

What would I need to know?

 

[roadtripper]

@EAN path is what I'd advise for a regularly used camper. I'd just wire the output of the charger direct to the battery (suitably fused) rather than looping back onto the low voltage side of the PSU.

If it's infrequently used then as far as I can see the internal PSU is on the dedicated 6A breaker - just turn that off.

It means you will draw a little more from the new lithium battery on EHU, but the capacity of the lithium will help offset that. And it sounds like you mostly use EHU for 240v.

In the interim you could buy a Victron/CTEK/NoCo mid level maintenance charger with a lithium profile to top the battery up if you needed. It's a useful thing to have around anyway.

So for your use I'd just carry on converting things to lithium and turn the breaker off - maybe put some tape over it as a reminder not to flick it back on. If you find everything is fine off the battery job done, if you find you need a bit more on long trips buy a maintenance charger to top up the battery.