12vdc Fridges - Average Power Used?

[MrRob]

I’ve recently installed a Dometic CRE80 in place of the old 3way in our camper.

We have just got back from 3 nights away to test it, the Victron Orion Smart 12 12 30 B2B charger and new 285ah deep cycle lead leisure batteries Ive installed work as expected.

We also wanted to see how long our Eco Flow River pro Lithium battery (62ah) will take the day to day strain of powering the fridge as it recharges fast off the generator whenever that is convenient/possible.

All works fine but I’m still unsure as to how much power the fridge is likely to draw on average as we saw it use 30ah and then 60ah in two days of similar use & weather conditions.

Anyone got some figures for actual battery use for similar dc fridges?

 

[mistericeman]

I’ve recently installed a Dometic CRE80 in place of the old 3way in our camper.

We have just got back from 3 nights away to test it, the Victron Orion Smart 12 12 30 B2B charger and new 285ah deep cycle lead leisure batteries Ive installed work as expected.

We also wanted to see how long our Eco Flow River pro Lithium battery (62ah) will take the day to day strain of powering the fridge as it recharges fast off the generator whenever that is convenient/possible.

All works fine but I’m still unsure as to how much power the fridge is likely to draw on average as we saw it use 30ah and then 60ah in two days of similar use & weather conditions.

Anyone got some figures for actual battery use for similar dc fridges?

Both our Waeco chest fridge
AND 240v under counter/Victron inverter fridges hit an average of 4 amps kicking in about once an hour for a few minutes (usually around 3 to 4 minutes when fridges in use)
Less when stuff is just shut up

 

[Fazerloz]

Our Waeco Cr65 runs 20mins on 20 mins off. Rated at 45w

 

[MrRob]

Our Waeco Cr65 runs 20mins on 20 mins off. Rated at 45w

Yep, that’s about what my CRE80 is doing I think.

 

[Fazerloz]

Yep, that’s about what my CRE80 is doing I think.

If your 80 is like our 65 there is a earth terminal next to the compressor that is not mentioned in the manual . Put a earth wire on to the van body.

 

[MrRob]

If your 80 is like our 65 there is a earth terminal next to the compressor that is not mentioned in the manual . Put a earth wire on to the van body.

I have high and low external vents (it replaced a traditional 3way) so may put baffling in to feed cool air & stop it mixing with heated exhaust air… but it’s a pain to pull as it is air tight to interior because it’s next to the water heater vent

… I could run thicker wire too.

 

[trevskoda]

My electric fridge has no cooling gear on the back and is completely sealed, burns a qtr of an amp when running which is not that often, it will run 24 hrs on 180 ah battery bank with out any solar, but I'm sure longer in summer when the 200w of panels kick in.

 

[Fazerloz]

I have high and low external vents (it replaced a traditional 3way) so may put baffling in to feed cool air & stop it mixing with heated exhaust air… but it’s a pain to pull as it is air tight to interior because it’s next to the water heater vent

… I could run thicker wire too.

It may be a pain to pull but it will be worthwhile in the long run.

 

[MrRob]

It may be a pain to pull but it will be worthwhile in the long run.

Yep, we are due to be away for 10+ days in the van on Monday so I’ll probably leave it until we get back. Lithium power pack and 30 minutes of generator each day should see us through for now.

 

[MrRob]

My electric fridge has no cooling gear on the back and is completely sealed, burns a qtr of an amp when running which is not that often, it will run 24 hrs on 180 ah battery bank with out any solar, but I'm sure longer in summer when the 200w of panels kick in.

My van has a 3D roof profile so stick on panels won’t work & I don’t want chunky framed panels up there either, hopefully I can get away without solar.

 

[wildebus]

My van has a 3D roof profile so stick on panels won’t work & I don’t want chunky framed panels up there either, hopefully I can get away without solar.

You could carry a portable solar kit. That could be handy to have? I have roof-mounted solar but also have a socket in the rear valance where I can plug in another solar array. (At home I plug into some panels I have on a shed roof to supplement the panels on the van roof).

 

[Nabsim]

I have a Waeco 110ltr e fridge freezer and it averages around 48amps in 24 hours

 

[Robmac]

Yep, we are due to be away for 10+ days in the van on Monday so I’ll probably leave it until we get back. Lithium power pack and 30 minutes of generator each day should see us through for now.

Will you be driving during those 10 days and charging the powerpack?

 

[r4dent]

I have a Waeco 110ltr e fridge freezer and it averages around 48amps in 24 hours

I think you mean "48 amp hours in 24 hours" !
One small word for a reply, one giant leap in consumption. averaging 48 amps would be over 1,000 amp hours per day.

 

[Nabsim]

I think you mean "48 amp hours in 24 hours" !
One small word for a reply, one giant leap in consumption. averaging 48 amps would be over 1,000 amp hours per day.

I have noticed you like to correct me as you have done the same correction before. Do you think anyone reading doesn’t know what I mean?

 

[r4dent]

I’ve recently installed a Dometic CRE80 in place of the old 3way in our camper.

Anyone got some figures for actual battery use for similar dc fridges?

Dometic quote an average of 2.16 amp. Over a 24 period this is around 50 ah.

Dometic Waeco Coolmatic - CRE80 Compressor Fridge | Electric Cool Boxes | Leisureshopdirect

Buy a Dometic Waeco Coolmatic - CRE80 Compressor Fridge | Electric Cool Boxes | Leisureshopdirect

www.leisureshopdirect.com

A 285ah lead battery will, without some charging, last almost 72 hours.

 

[r4dent]

I have noticed you like to correct me as you have done the same correction before. Do you think anyone reading doesn’t know what I mean?

Yes I do.
There are many members who don't understand the difference. A lot are confused by all the different units involved in electricity.

Didn't mean to upset or insult you, just trying to avoid misunderstanding by members who don't know their amp from their watt.

 

[r4dent]

Both our Waeco chest fridge
AND 240v under counter/Victron inverter fridges hit an average of 4 amps kicking in about once an hour for a few minutes (usually around 3 to 4 minutes when fridges in use)
Less when stuff is just shut up

I assume that is 4 amp at 230v (about 50 amp at 12v).

 

[wildebus]

I assume that is 4 amp at 230v (about 50 amp at 12v).

no, that will be 4A at 12V. Around 50W.

I don't think ANY normal fridges draw close to around 1000W in use!

 

[MrRob]

Dometic quote an average of 2.16 amp. Over a 24 period this is around 50 ah.

Dometic Waeco Coolmatic - CRE80 Compressor Fridge | Electric Cool Boxes | Leisureshopdirect

Buy a Dometic Waeco Coolmatic - CRE80 Compressor Fridge | Electric Cool Boxes | Leisureshopdirect

www.leisureshopdirect.com

A 285ah lead battery will, without some charging, last almost 72 hours.

Ha yes, thanks. I’d read that before I purchased but almost ignored / forgot it as I have no idea how their test conditions or use varies the real world results.

Oddly with us the lower 30ah day shows an average of about 23 degrees inside the van and the 60ah day was cooler average of 21 (but much more wind into the vents) although temps did peak higher at 26 just before sunset when sun reflected off the puddles in car park!

Probably too soon to make any big adjustments to our system.

Will you be driving during those 10 days and charging the powerpack?

Yes. Although I’d aim to recharge the leisure batteries then. The 8 amps the lithium pack will take (from the 30 available from the B2B) can quickly be made up from the generator at 40-60 amps input.

I will probably wire a 12v feed between starter battery and lithium pack (and power fridge) to bypass the B2B when on the move at some point.