Battery doubts

[rnpr4541]

Hello,

I've a new fridge (Waeco cf35) and I will run only using the main battery because I cannot afford a dual system at this moment, my Lc is a KZJ95.
I need to buy a new battery and I'm having some doubts on which will be the better option. A Deep cycle one, with less amper hour or a "normal" one with more amper hour.

I'm looking to this one from varta:

[h=1]VARTA SILVER DYNAMIC 12V 85Ah F18 800A[/h]
[h=1]VARTA PROFESSIONAL DEEP CYCLE LFD75 12V 75Ah 650A[/h]
[h=1]VARTA BLUE DYNAMIC 12V 95Ah G8 830A[/h]
My main doubt is, since I'm gonna use only one battery to have the fridge constantly on, should I get more amps or a deep cycle battery?
Thanks,
Rui Rodrigues

 

[grantw]

Just looking at the consumption of the fridge (http://www.waeco.co.uk/page.aspx?page=powercon&s=4) and in a 24 hour period at 30 degrees it would take 24 AH. Which seems pretty reasonable. So that would be around 30% of your battery (for the deep cycle) or 25% for blue dynamic if you don't drive for a 24 hour period. 25% seems like quite a bit for a non deep cycle battery on a regular basis.

I don't really know the answer but hopefully providing a little more information for someone that can!

 

[rnpr4541]

Thanks Grant,

I don't think that I will stay 24hours without driving. Usually I will stop during the night and drive the next day.

 

[grantw]

I don't think with that kind of use ... with 12 hour odd stops you would do a lead acid battery too much damage!

 

[Shayne]

Surely any fridge is governed by its own thermostat so when constantly closed (ie through the night) it will only take maybe 2 minutes of power every hour to keep the set temperature . During the day its motor will run everytime someone opens it letting heat in and cold escape , but with the engine running it shouldn't matter .

 

[grantw]

Shayne - for the very bais calcs I just took what was from that link on the official power consumption. No idea re the closing or opening. Their figures were quoted when running as fridge only (doubles for freezer) and at 30 degrees.

 

[rnpr4541]

Thanks guys,

I see that I probably don't need a deep cycle battery and can get one with a higher amount of AH. It will do the job...

 

[Chris]

I have the CF 40 and with my leisure battery alone it will run for nearly a week before it shuts off. You can set the point at which it shuts off to protect your main battery. Somewhere like 12v, 11v and 10v so that it will leave you enough to start up. If you have the insulating jacket and you arrange the fridge properly, don't leave the lid open all the time, the consumption is very low indeed. Once cold, it stays cold for quite some time.

Chris

 

[Shayne]

Shayne - for the very bais calcs I just took what was from that link on the official power consumption. No idea re the closing or opening. Their figures were quoted when running as fridge only (doubles for freezer) and at 30 degrees.

I'm a low tech bloke precision for me means an inch and a smidgen and it'll fit if you hit it hard enough . I just figure it makes sense that theres nothing to power once the fridge or freezer reaches its required temperature .