Help to work out AH draw on cooler box please

[Djtemeka]

I have a Halfords cooler box that I use whilst camping.
My question is, is the 3.5A draw of the cooler per hour? So if I had it running constantly (3.5x24) it would use 84 AH over the 24 hours and thus 168AH over the weekend or would this draw slow down once the cooler is at temp? It is a fan cooler not an actual fridge. Im not great at the maths side of things and any battery over 200AH is rather expensive.
I have a split charge system in my van that charges it until we get to our destination.
Really all we need to use it for is the fridge and maybe charging the phones everyday for 2 days without depleting the battery.

What AH battery should I get as the one I currently have is flat after around 30 hours

http://www.halfords.com/camping-leisure/camping/co...



Halfords 40 Litre Mains and 12V Electric Coolbox Extra Info


Wattage is 42W. Draw in amps is approximately 3.5A from a 12V supply
Wattage is 55W. Draw in amps is approximately 0.25A from a 240V supply

[spookly]

Djtemeka said:

I have a Halfords cooler box that I use whilst camping.
My question is, is the 3.5A draw of the cooler per hour? So if I had it running constantly (3.5x24) it would use 84 AH over the 24 hours and thus 168AH over the weekend or would this draw slow down once the cooler is at temp? It is a fan cooler not an actual fridge. Im not great at the maths side of things and any battery over 200AH is rather expensive.
I have a split charge system in my van that charges it until we get to our destination.
Really all we need to use it for is the fridge and maybe charging the phones everyday for 2 days without depleting the battery.

What AH battery should I get as the one I currently have is flat after around 30 hours

http://www.halfords.com/camping-leisure/camping/co...



Halfords 40 Litre Mains and 12V Electric Coolbox Extra Info


Wattage is 42W. Draw in amps is approximately 3.5A from a 12V supply
Wattage is 55W. Draw in amps is approximately 0.25A from a 240V supply

Yes, 1A for 1 hour = 1AH

Yes, big batteries are expensive.

12v coolbox/fridges are a bit rubbish when the weather gets hot. Buy one that is dual electric/gas instead of an expensive battery.

[OldGermanHeaps]

The peltier coolers in those are ridiculously inefficient. Find a used fridge out a breaking caravan.

[Djtemeka]

Looking at used fridges, they seem to use more amps? Would a 100w solar panel be enough to top up the battery?

Thanks
J

[spookly]

Djtemeka said:

Looking at used fridges, they seem to use more amps? Would a 100w solar panel be enough to top up the battery?

Thanks
J

You'd be lucky to get 100W from solar advertised as 100W even on a sunny day... so check what real output is....but

100W at 12v would give you around 8A. But in reality there will be losses in cables/controller etc. A good estimate on a sunny day would be about 4A.

That would run the fridge and maybe put a *little* charge in the battery. Assuming you get 6 hours of sun in a day, it'll maybe save you 7 hours of drain (run on solar for 6 hours and add the equivalent of 1 hour back in recharge). So then you could recalculate your usage based on 17 hours use a day. Assuming you have decent sun.

Depending how often you'll use it, it might actually be better to have a split charger for your vehicle and recharge off the alternator.

A decent 100W solar and controller will be £200+, 200W would be more like £400+

[Djtemeka]

I've got a split charger in my van already so the battery is charged all the time but when camping, I'll not be using the van and don't fancy it just idling there all day.

Usually, I arrive on a Friday eve and the battery runs fine all sat then goes flat by early Sunday morning so in reality I'm only looking for around 10 hours extra charge but of course I'll need more as the battery is really flat by then.
Looks like I'll use 1 battery per day so u sure of the solar panel vs just using a 3rd battery on the Sunday.
Battery will probably be cheaper but more of a faf.

Perhaps a bigger battery and the solar panel? 100w panel should do if I'm using that per day.

[TooMany2cvs]

Djtemeka said:

My question is, is the 3.5A draw of the cooler per hour? So if I had it running constantly (3.5x24) it would use 84 AH over the 24 hours and thus 168AH over the weekend or would this draw slow down once the cooler is at temp?

Yes, 3.5A for 1hr is 3.5Ah. But you're right that, once down to temp, it'll cut in and out.

Either way, though, it's not going to do a battery any favours if you leave it connected and on all the time...

[Wedg1e]

I found that if you're taking gas cooking equipment you may as well take a gas fridge; the typical Electrolux caravan fridge could be had as gas only, gas/12v, gas/240v or gas/12v/240v. For the minimal difference in space over a coolbox I'd take the fridge every time, especially as you have a van.
I had a couple of trailer tents and quickly worked out that once you're going 'fully-loaded' for camping some things are just best done properly.
Nowadays I use a Coleman petrol stove and Northstar petrol lantern, since you'll be able to lay your hands on petrol on a campsite on bank holiday Saturay night far easier than you can gas. Shame nobody does a petrol fridge

[garagewidow]

regularly charging and discharging a battery does it no favours and will quickly shorten its life unless you have a spiral wound cell or gel filled one like an optima type battery specially designed for this purpose.

if you use campsites for a short period at a time I would recommend top ups with ice packs to prevent complete discharge of the leisure battery,they will give you the extra time/cooling capacity.
but best bet is a gas fridge or dual fuel.

[Djtemeka]

Will get a gas fridge in the future.

Found out that the 90ah regular van battery that I had was dying when I took it to my autoelectrician to test. He had a machine that prints out a lot of weird info and the life of the battery wasn't good.
Got a 115ah marine leisure battery now and a 120w foldable solar kit. Also taking my multimeter along to check the discharge rate so I don't discharge it too much. Also got one of those phone battery packs but that is also npbuilt in solar. Th regular types are 5000-6600mva (?) and this one is 15000mva so it can change up to 8 iPhones or 3 iPads.

Will see how I get on. My best mate and my wife are laughing at me ( I always buy tat that I never use) but we will see who laughs when I have cold beer and a working mobile. Battery flat love? £10 please.... Or a blowie

[Wedg1e]

Djtemeka said:

My best mate and my wife... Battery flat love? £10 please.... Or a blowie

I have some quite good mates but I'm sure they'd cope for a couple of days with a dead phone rather than give me a blowie

[Djtemeka]

Wedg1e said:

I have some quite good mates but I'm sure they'd cope for a couple of days with a dead phone rather than give me a blowie

Hahahaha. My mate can. My wife? She'd be gargling after an hour without her phone