Upgrade Leisure Battery to Lithium with EC155

[Sprout]

Hi

Newish to the forum (read loads) and had the van for a year or so now…

Current leisure battery very smelly (rotten eggs) and not holding charge (drops to 11.4v within an hour of being charged) so assume it is knackered. Am planning to add solar in due course so thought I might as well upgrade the DC to DC charger to one that can cope with solar and Lithium as want to avoid hooking up unless absolutely necessary. Current configuration is as per picture with a Sargent EC155 psi.



I’m no electrical expert and having read a lot of the helpful content I think I need to remove the charger fuse on the EC155 but I can’t turn off the breaker as it covers the fridge as well. So if I needed to charge the Lithium battery whilst hooked up I assume I can plug a charger directly in to one of the van’s plug sockets.

Was looking at Renogy DCC30S and a Pro LiFePO4 100ah battery - assume these two are compatible. I only have a fridge to run.

Any guidance appreciated…

 

[roadtripper]

Have a look at this thread which covers a very similar upgrade

Upgrade from Sargent EC155 Advice Request

Hi all I've been running the Sargent EC155 for the last 5 years or so and it's done the job. I've just upgraded to a Lithium Fogstar battery from my lead acid LB and the Sargent now keeps alarming randomly for high voltage. I've not changed anything else and have read that the Sargent's don't...

www.t6forum.com

Your Sterling charger looks like it's a LiFePo capable one - can you get a clearer image of the top left?

Ideally yes you should disable the "charger" in the ECC155 as it's not ideal for a lithium profile and fit something like a Victron charger.

Remember with LiFePo you must have a low temperature cut off in all chargers or built into the battery - with prices dropping I wouldn't advise buying a battery without that built in.

 

[Sprout]

Thanks - hopefully the below is clearer. If it is ok then I can just add a mppt when I get round to solar.

I take it just removing the fuse is not sufficient to disable the charger. Dumb question - do I need to wire the lithium charger in?

Thanks for advice on battery as I’m up in Aberdeen so temperatures do drop.

 

[roadtripper]

So yes yours is LiFePo capable - the top left of the black display

One thing I don't like about this range of chargers is the re-use a lot of the indicators - and in this case they ran out of battery type indicators in the "input voltage" block so they used one of the cycle indicators - very confusing.

You may still want to upgrade the Sterling at some point but if you want to do a rolling upgrade you should be able to reconfigure it to LiFePo profile. I warn you it's a bit of pain to do that on that charger.

I think on the EC155 pulling the charger fuse should be fine.

I think the voltage put out by the EC155 is low enough it actually wouldn't be enough to charge the lithium battery so in an emergency you could always turn that back on to support your 12v electrics if you had to. I'd just personally feel a bit uncomfortable having such a basic charger (it's not even that really just a power supply) in the mix all the time with a lithium battery.

 

[Sprout]

Thanks for all the guidance/advice. I’ll order the battery and have a go at changing the profile.

 

[roadtripper]

A LiFePo is likely to be a different (smaller and lighter) physical size to your current battery - make sure you have a plan for securing it as well as having new terminals if needed and covers.

Before diving in I'd also check the voltages around the battery and observe the Sterling running and check it's behaving. A strong egg smell normally means the battery is being over charged rather than under charged...

 

[Sprout]

I did check the voltages before I started the van it was at 11.4v and my son had just got back from a week in Arran so I expected it to be higher. I started the van it was being charged at 14.53v. When I stopped the van it gradually reduced down to 11.4v.

 

[roadtripper]

That's quite a high voltage for a standard/wet battery - what profile is the Sterling currently set to?

 

[Sprout]

I did wonder - it was AGM2. I’ll download the manual for it and look up how to change it.

 

[roadtripper]

These are the profiles I can find in the manual - possibly with the note you may see 14.5v for the first couple of minutes?

Just want to make sure that your Sterling is not the root issue before you swap batteries... That NUMAX looks like a sealed battery so if you've been getting a smell from it's been gassing enough to force it to vent...

 

[Sprout]

Would the wrong profile mean it was being charged for too long? It’s definitely been venting - the smell was coming from under the drivers seat.

 

[roadtripper]

Sort of, it would have been charged at too high a voltage. That means the battery likely was charged way before the Sterling thought it would be and may have been charged at a higher rate for a long while if it never reached the voltage to trigger the next stage.

Make sure you are reading the displays on the charger correctly - the battery type indicator is a flashing one and only shows in charger startup (not engine startup) - there is a button combination in the manual to check at other times. If it's steady it's reading input voltage.

 

[Sprout]

Ah…ok will check tomorrow as will need to put the seat back in to avoid airbag issues. Thanks

 

[roadtripper]

I did wonder how you were getting such good pictures

 

[Sprout]

I took these 5 mins apart - the voltage stayed pretty much the same over a 15 min charging period. In terms of battery type - on start up of the charger it flashed calcium twice very quickly and then was just steady green light.

 

[roadtripper]

Looking at the chart above "Calcium" is a very high voltage profile - that might be the root of your issue.

From the manual this is the procedure to set the profile type - would be useful to set it to "Sealed" and see if the voltages during charging are more rational (and show the Sterling is behaving)

 

[Sprout]

Thanks - changed it to sealed and it’s running at 14.35v even after 10 mins or so. I’ll run it like this for a while and see if the smell comes back and see how the battery does. I’m going to order the Fogstar drift 105 as that will easily fit in and I’ve got a few weeks to work out how to secure and also whether I need to change the charger as well in that time.