Making the change from lead acid to lithium - a thread with pictures

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So, after being lucky enough to get a lithium battery for less than half price, (thanks Jim), this thread will be the process for how I have changed over.

I may be talking to myself a lot but that’s okay, I always search for rubbish like this when I do anything so I am hoping it will help in future.

I have a Hymer with a decent split charge relay. Currently have 350 watt of solar via a Votronic MPPT. That has a lithium profile so all good.

I will however need a B2B so again going for a Votronic model. Partly because they have clear instructions and will work with the EBL Hymer install.

I am going for the 30 amp model.

<Broken link removed>

I would like more but in full sun, the solar can pump out 15 amps and the maximum charge capacity of the lithium is 50 amps.

ecotreelithium.co.uk

12V 100AH Lithium Leisure Battery LiFePO4 - Eco Tree Lithium LiFePO4 Battery

6 Year Warranty with UK company in Nottingham, Only High Quality Cylindrical Lithium Cells. Built in BMS. 12 Volt with 100 Amp Hour Capacity
ecotreelithium.co.uk ecotreelithium.co.uk

I have 200ah of lead acid. Payload is tight and the extra capacity of lithium means I can take a 100ah lithium down to 10% giving me only 10ah of usable power less than the lead acids. I don’t think I will need two lithium’s and at £700 each, probably just as well.

I will post pictures as I plan and rip out the old stuff.
 
If you did well with 200ah lead, the 100ah Li will be sufficient and a improvement. The charge efficiency is almost 100%, meaning you don’t have to put in more than you took out with the lead.
 
Raul said:
If you did well with 200ah lead, the 100ah Li will be sufficient and a improvement. The charge efficiency is almost 100%, meaning you don’t have to put in more than you took out with the lead.
Click to expand...
Only ever nearly run out once.

I didn’t realise lithium charged more efficiently too. Happy days!
 
This is my current setup, space is tight and to be frank, it’s a mess!

7D66B3E9-C5C2-4E78-A138-E39DD68608DA.jpeg
 
Not far for the invertor, 1200w PSW. The cables where it connects though seem to get hot at full whack so will be re doing those connections too.
8EF8E833-A8DC-4EB3-A9ED-32E3E6BFCEBE.jpeg


You can also see the Votronic MPPT which I will be moving to inside the battery compartment where there will now be room after ditching the second battery.

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Googlebot said:
Just gone to clean up the compartment by switching the inverter on for the vacuum. Yes I am stupid! 🙄
Click to expand...
Yes, just the sort of thing I do. Like wringing out the cloth I've used to mop up the under sink when I'm replacing the sink waste! Good luck with this. Following with interest.
 
Just realised that the old solar controller I have won’t be compatible with lithium.

I have two, one for a 250 watt panel which I installed which is the Votronic and the older one which doesn’t have a lithium setting and is connected to a 90 watt panel from when I got the motorhome.

That’s annoying as I will also need a temperature probe for a new Votronic controller as well as one for the controller I already have.

As reluctant as I am to spend another £100, a 90 watt panel will help top up the lithium in the darker months and as all the cable panel are there, I may as well do it properly.
 
Googlebot said:
Just realised that the old solar controller I have won’t be compatible with lithium.

I have two, one for a 250 watt panel which I installed which is the Votronic and the older one which doesn’t have a lithium setting and is connected to a 90 watt panel from when I got the motorhome.

That’s annoying as I will also need a temperature probe for a new Votronic controller as well as one for the controller I already have.

As reluctant as I am to spend another £100, a 90 watt panel will help top up the lithium in the darker months and as all the cable panel are there, I may as well do it properly.
Click to expand...
I have a Votronic 430 with the temp cable that I need to sell if of use?

Only used it for a few weeks (changed my panels and needed higher VOC), cable still new in box.

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Hello, long time lurker here, but following with interest. As a drop in replacement, does the Eco Tree need a lithium profile, or will it manage the charge itself using a Lead Acid profile?

Do you have a mains charger that also needs a lithium profile?
 
Wissel said:
I have a Votronic 430 with the temp cable that I need to sell if of use?

Only used it for a few weeks (changed my panels and needed higher VOC), cable still new in box.
Click to expand...

It would work but is bigger than I need so not sure you would want to part with it for the same price I could get a smaller Votronic one? It’s a kind offer though if you just want rid?


a5436 said:
Hello, long time lurker here, but following with interest. As a drop in replacement, does the Eco Tree need a lithium profile, or will it manage the charge itself using a Lead Acid profile?

Do you have a mains charger that also needs a lithium profile?
Click to expand...

It says drop in, but a battery to battery charger will protect the alternator and vehicle as well as give a higher charge rate.

With regards to the solar, I already have a lithium profile on one.

It would probably be fine, but I am not prepared to risk knackering a £700 lithium.
 
Googlebot said:
It’s one way of fixing the battery down, but not one that I would do.
Click to expand...
Common dealer method when fitting a second battery.
Googlebot said:
Just gone to clean up the compartment by switching the inverter on for the vacuum. Yes I am stupid!
Click to expand...
I agree. :rofl:
Googlebot said:
Just realised that the old solar controller I have won’t be compatible with lithium.

I have two, one for a 250 watt panel which I installed which is the Votronic and the older one which doesn’t have a lithium setting and is connected to a 90 watt panel from when I got the motorhome.

That’s annoying as I will also need a temperature probe for a new Votronic controller as well as one for the controller I already have.

As reluctant as I am to spend another £100, a 90 watt panel will help top up the lithium in the darker months and as all the cable panel are there, I may as well do it properly.
Click to expand...
Your Votronic regulator will take 350 watts of panels so you don't need another one.
 
Googlebot said:
It would work but is bigger than I need so not sure you would want to part with it for the same price I could get a smaller Votronic one? It’s a kind offer though if you just want rid?
Click to expand...
Tbh I was scan reading and didn't notice the small one would sort you out.
Lenny HB said:
Your Votronic regulator will take 350 watts of panels so you don't need another one.
Click to expand...
Looks like your sorted anyway :giggle:

Good luck with your upgrades. I use the big Votronic B2B with my LiFePO4, have used Votronic MPPT's and fitted the B2B you linked to in another van. All have worked great (y)
 
Lenny HB said:
Common dealer method when fitting a second battery.

I agree. :rofl:

Your Votronic regulator will take 350 watts of panels so you don't need another one.
Click to expand...
Thanks Lenny, alas they are completely different panels. One is 250 and one is 90 I think.

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Wissel said:
Tbh I was scan reading and didn't notice the small one would sort you out.

Looks like your sorted anyway :giggle:

Good luck with your upgrades. I use the big Votronic B2B with my LiFePO4, have used Votronic MPPT's and fitted the B2B you linked to in another van. All have worked great (y)
Click to expand...

Always good to hear other peoples experience of the kit and reassuring it worked as intended.
 
the1andonly said:
It's the voltage that maters not the power eg dont mix a 19V With a 39v, 48v version( nominal 12v, 24v domestic
Click to expand...

I vaguely remember checking when I got the new panel. They are different voltages which is a pain.

I am sure that’s why I kept the old controller instead of bunging it all in the Votronic. Apparently from what I have read, they will work but the lower voltage panel will drag the higher one down and affect the performance by quite a margin.

Getting a new controller isn‘t a deal breaker, means I have redundancy if there is an issue and I can put a bigger panel on if the current 7 year old one expires.

I can say one thing, a proper system ain’t cheap! Lead acid or lithium. 😢
 
Lenny HB said:
Disconnect the panels and measure the open circuit voltage on a bright day.
Click to expand...

I did Lenny, I looked back through other postings I made and it jogged my memory.

Did it when I installed the 250w panel.

From memory, it was over 10 volts difference.

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That’s buggered it again!

Just checked the specs of my big panel, it’s a 275 watt and not a 250.

That means it’s too much for the one controller I have if I stick in the 90 watt as well.
fullfat said:
250 and 90 watts ?
Click to expand...

As above I am afraid, one is an old 90 watt and the other newer one is a 275 watt.

I reckon I can get a 150 in the place of the 90 watt though, so I might wait till the 90 expires and go that way.

Not easy this motorhome stuff is it? 😂
 
Count the cells on the panel. The 90w I guess is a 12v 36cells and the 275 is a 30v 60 cells panel.
Agree is cheaper to get another 275w panel, if controller allows.

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