Isotherm fridge short cycling and draining leisure battery or failing battery causing short cycling?

[Mescovery]

This weekend the fridge started short cycling (runs and cuts out after about a minute, stops for 3 seconds then starts up again and repeats this ongoing, still cooling) and it drained the leisure battery during the night to the point where the Sargent control panel started to beep occasionally to warn the battery was too low.
When I switched to the car battery instead of the leisure battery it seemed to run normally.

There was a rug in front of the fridge which may have blocked ventilation? But it has been there previously and not caused an issue.

Do you think it’s the battery not holding charge enough to power the fridge sufficiently which is causing the short cycling or is there something wrong with the fridge which is draining the battery?

Thanks.

 

[Nigel W]

If it ran normally on the vehicle battery then I would suspect your leisure battery has reached the end of its life, easiest way to check is to replace the leisure battery with another (perhaps you can borrow one or take the battery out of another vehicle?
Failing that take the leisure battery to a dealer and ask them to test it for you - Halfords perhaps?

 

[cgtmiles]

The cycles on the fridge should be much less at night than during the day so could it be that it was working overtime during the day (possibly with heat and unsatisfactory ventilation to deal with) and then when it did switch on during the night it tipped the battery over or was it doing crazy cycling at night too?

 

[Mescovery]

It’s surprising to think the battery is already worn out as I’ve just bought the van. It’s a 2018 with a conversion done around 2019/2020 so the battery is only about 2 years old and has hardly been used.

 

[Pete C]

If the previous owner let the leisure battery go flat even once, then it could be irreparably damaged.

Pete

 

[Ads_Essex]

It’s surprising to think the battery is already worn out as I’ve just bought the van. It’s a 2018 with a conversion done around 2019/2020 so the battery is only about 2 years old and has hardly been used.

As Pete said, it doesn’t take much.

Out of curiosity, what make, type and size is the LB?

 

[Alanmh]

Isotherm fridges cause quite a high current on startup. This drops the voltage from the battery, which then causes the fridge to cut out as it senses “low battery”. I had a similar problem with my fridge which also has an isotherm compressor. First thing to check I that the cabling to the fridge is big enough. My cables were undersized and dropping a further 1volt.

That said, I have now replaced with a lithium battery to solve the problem after replacing 2 lead acid batteries in 4 years!

 

[Mescovery]

Thanks all. It’s a E-110 Low/14461100 (I believe it’s an Enforcer) battery. I think I will replace it with a lithium one.

 

[cgtmiles]

Which Sargent control panel have you got? I believe the built in mains charger on mine isn’t suitable for posh battery’s so as I’m using a b2b charger already it would be a very bulky fuse board if I upgrade!

 

[Ads_Essex]

Thanks all. It’s a E-110 Low/14461100 (I believe it’s an Enforcer) battery. I think I will replace it with a lithium one.

This one?

Enforcer Leisure/Caravan Battery Lowcase 110Ah 12V (6110) from County Battery

Enforcer Leisure/Caravan Battery Lowcase 110Ah 12V (6110) is a Caravan / Motorhome Battery from County Battery. Buy Online before 2pm for free, same day dispatch

www.countybattery.co.uk

Lead acid with only 400 cycles means it’s a budget option.

Lithium is quite a jump. For what it’s worth I’ve had a 110Ah AGM that’s lasted me 3 years and that’s with it having been almost discharged a few times.

 

[Nigel W]

If you do go for a lithium battery then you will need a new charger as the inbuilt Sargent charger is unsuitable.

 

[Mescovery]

This one?

Enforcer Leisure/Caravan Battery Lowcase 110Ah 12V (6110) from County Battery

Enforcer Leisure/Caravan Battery Lowcase 110Ah 12V (6110) is a Caravan / Motorhome Battery from County Battery. Buy Online before 2pm for free, same day dispatch

www.countybattery.co.uk

Lead acid with only 400 cycles means it’s a budget option.

Lithium is quite a jump. For what it’s worth I’ve had a 110Ah AGM that’s lasted me 3 years and that’s with it having been almost discharged a few times.

Similar yes maybe a slightly older version of it. Doesn’t have the red part.

The Sargent unit has an EC50 control panel. Not sure what else it includes.

Do you think going for an AGM battery would be better then instead of a Lithium one?

 

[Ads_Essex]

Do you think going for an AGM battery would be better then instead of a Lithium one?

No, going for a lithium would be “better” than all other types, but you could try AGM instead of your LA type. Check out prices and see what suits, whilst also taking on board what has been said about low-battery sensitivity, cabling size and your charger type.

If you’re unable to leave your camper plugged in so it receives either a trickle charge or weekly/fortnightly recharge, then you’ll be back here with the same problems, so should also consider fitting a solar panel to help maintain the the charge level of the leisure battery (you’ll also want to keep your vehicle battery topped up if you leave the van sitting for more than 7/10 days depending on the make and health of that battery).

 

[Mescovery]

It has a small solar panel connected. I plugged in the EHU for a couple of hours yesterday and the battery level still doesn’t really go about 3/5 lights on the control panel. It still seems to run reasonably ok for now and is still at 3/5 lights today.

Should driving it regularly (every few days, albeit shorter trips) be enough to keep it topped up or should I plug in the EHU more often?

 

[Ads_Essex]

Should driving it regularly (every few days, albeit shorter trips) be enough to keep it topped up or should I plug in the EHU more often?

EHU

 

[cgtmiles]

It has a small solar panel connected. I plugged in the EHU for a couple of hours yesterday and the battery level still doesn’t really go about 3/5 lights on the control panel. It still seems to run reasonably ok for now and is still at 3/5 lights today.

Should driving it regularly (every few days, albeit shorter trips) be enough to keep it topped up or should I plug in the EHU more often?

Do you keep the fridge on 24/7? If so I think you will struggle if not driving or hooked up to EHU constantly 24/7 too.

The mains charger in the Sargent is like a trickle charger so quick blasts won’t really help especially if the fridge is running at the same time.

 

[Mescovery]

Unless we’re going away on a trip camping I don’t run the fridge or anything off the leisure battery. The whole thing is switched off at the little control panel (I don’t touch the on off button on the big Sargent control unit, should I?). When we just go on a camping trip I did have the fridge on the whole time and we drove about an hour, then camped for the night and during the night the fridge drained the battery. The battery goes up to 3/5 lights full when I drive and then looses charge very soon after. I think I will try a new battery.
What’s the best highes aH battery to get compatible with the Sargent set up as it is?