Dometic Crx50 Working Ok?

[LSNE]

OK so I camped in the van last night and noticed the fridge was kicking in a lot more regularly than I remember.

Fridge was taken to temperature while on hookup and cold beer was added.
After a few hours on hookup I disconnected to make sure the rest of the system was still working but knocked the fridge temp down to number 2.

I checked the BM2 readout and it shows the voltage dropping regularly. Should the fridge be kicking in this often?

95ah leisure battery
Ablemail AMS B2B
150W solar panel.
Outside temp 13 degrees.

Screenshot_20200405-201509_Battery Monitor

• LSNE
• 5 Apr 2020

 

[cgtmiles]

you can see mine kicking in through the night here 2 to 3 times an hour but then I switched off and disconnected from mains. I guess during the day it would come on more regularly if the van was heating up

 

[LSNE]

The pattern looks similar.

Can I ask what reading your leisure battery sits at at rest with no load?

 

[cgtmiles]

During the day it’s taking charge from the solar panel all day but you can see what it drops to over night that should be with no load

 

[LSNE]

So does it maintain 12.8/12.9v even after 24 hours of no hookup?

 

[cgtmiles]

Well the solar panel is charging during the day. I only fitted the battery monitor the other day so not sure if normal yet

 

[bullracing]

With only 1x 95ah battery it will go down. Your using it.

Any lights, heaters on or solely the fridge?

 

[bullracing]

I have 2x 110ah with a 400w solar. It sits at 14.4v all day. Over night with fridge, lights, phone, ipad charging and heater on all night even mine drops to 12.5v-12.3v sometimes. Take away any power usage it does level out around 12.7v.

 

[LSNE]

Yeah, mine is dropping to 12.4v overnight with nothing running, just want to make sure that's normal and my battery isn't on it's way out.
Looking at some of the charts online that would make it only retaining 80% charge.

Looks like the solar output from my B2B is no good. I've just wired my MPPT back in and it looks like it's charging again.

I'll monitor the fridge usage over the next couple of days to see how it behaves.

Alternatively, I think I may need to stop monitoring the battery voltages. Damn @Dellmassive and his recommendation of the BM2 monitors.

 

[bullracing]

Its bad, atleast you have admitted you have a problem, thats the first step to getting better. Ha Ha. I've unplugged my BT adaptor or im at the window morning and eve checking the app.

 

[Dellmassive]

LOl . . . Glad to help.

main link - Battery Monitoring -- How I Done It --

here are some T6 static power charts (no fridge running) : Battery Monitoring -- How I Done It --

and here are some battery draw BM2 charts with Dometic fridge and solar : Mobile Solar Panels ? . . . - How I Did It -


it looks like the Dometic Fridge will cycle the compressor between infrequent and often depending on the ambient temperature at the fridge setting & contents . . .

FYIW - out T6 starter battery has a rest voltage of around 12.2v (stable all night) with daily driving usage . . . which is Normal for this van. . . . . ., even though the documented charts will state that a fully charged AGM starter battery should be 12.6v . . . . . for us 12.2v is normal and will last for around 3wks if not started before a No-Crank situation.