heat tank of 500watt heater using leisure battery

Hi 

I'm looking to buy a 500Watt heater to heat my 500 litre tank and hoping to use a leisure battery to power it instead of the mains so i have warm water all day and to stop from freezing up is this possible i have a relay system that charges my battery as a drive.

Thanks 

Don’t think it will do much to be honest . 

500watts at 12v is 41Amps. So if your battery is 100Ah then you can run the heater for about 1hr before the battery is close to flat!!!! If you didn't know if you pull more than 50% of the Amp Hrs out of a lead acid battery you will damage it.

Realistically running a heater off a battery is not going to work! If you can't get mains electricity to the van to run an immersion heater (2Kw and installed safely) then the only other option is a diesel heater.

ched999uk said:

500watts at 12v is 41Amps. So if your battery is 100Ah then you can run the heater for about 1hr before the battery is close to flat!!!! If you didn't know if you pull more than 50% of the Amp Hrs out of a lead acid battery you will damage it.

Realistically running a heater off a battery is not going to work! If you can't get mains electricity to the van to run an immersion heater (2Kw and installed safely) then the only other option is a diesel heater.

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If the op doesn't understand the amps etc of a battery then safe to say get an autospark or electrician to install it.

I grew up with my dad being a qualified autospark and proper electrician so couldn't get a better grounding in electrics and can read vehicle wiring diagrams etc and have still fried a flow controller by touching the wrong wire and letting the smoke out lol.

I do know that leisure batteries going below 50% damages them but in my experience (using the same battery for over 3 years each time) that a normal car/van battery (I use an 80ah one) doesn't seem to care if it goes flat the same as running it flat trying to crank a stubborn engine over.

This is why brodex use them rather than leisure batteries.

I don't understand why most choose to use leisure and marine batteries.

Splash said:

Hi 

I'm looking to buy a 500Watt heater to heat my 500 litre tank and hoping to use a leisure battery to power it instead of the mains so i have warm water all day and to stop from freezing up is this possible i have a relay system that charges my battery as a drive.

Thanks 

Click to expand...

Not possible for any 500w heater to heat 500ltrs of water to a reasonable temp even if it was mains powered 

Iron Giant said:

Not possible for any 500w heater to heat 500ltrs of water to a reasonable temp even if it was mains powered 

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If it did work everyone would be doing it. ?