[easy clean]

thinking of the winter, sorry to put a bit of a downer on it but winters only around the corner. how can i stop 650 litres of water freezing in the back of my van

i have an inverter (120 watt) in the van which i use to keep the trolley battery charged, was thinking of putting a 80 watt heater in the van and powering it off the van battery throught the inverter to keep the water from freezing. the van battery is about 500 amps so was wondering how long would the battery power the heater for till it ran out of charge. if that makes sense

[EasyClean]

Insulate your water tank with 'ThermaWrap' insulation from www.thermawrap.co.uk It's like bubble wrap coated both sides in silver foil, (it works by reflecting radiant heat much like light hitting a mirror) I use it for keeping my hot water hot in my van mounted tank. It's the best stuff I've come across. Simply cut to size with a pair of scissors and apply to water tank using double sided sticky tape.  All you have to do now is figure out how to heat your water.
You could use a wind turbine heater element which dumps excessive battery charge to a heating element fitted to a water tank to prevent charging batteries being overloaded. You can buy a small amperage heater element that doesn't draw many amps and prevents frost damage. You could connect it up to a spare battery ensuring you wire it through a switch to run overnight.

[EasyClean]

My WFP water tank is insulated with 'thermawrap' permanently inside my water tank frame.
I also have a 'calorifer tank' fitted inside my van which is connected up to the engine radiator hoses. The heat from the engine which normally runs over a radiator runs inside my 'calorifer tank' through a  'heating element' which is surrounded by 75 litres of de-ionised water stored in this boiler shaped calorifier tank. The mixture of water and antifreeze that passes through my calorifier tank heating element from the engine is approximately 85degrees celsius which soon heats up my 75 litres of stored water also in the calorifier tank. Because of the way I have this set up I can either use my stored water directly passing it through a DI bottle to give it a final polish prior to going up my WFPole for window cleaning (this water is VERY HOT-too hot for single glazed panes of glass in the winter) OR I can re-circulate my heated water into my cold water storage tank thus warming up a larger quantity of  cold stored water for window cleaning. Have a look at www.surejust.co.uk to get a general idea of what I'm talking about. I can heat up 75 litres of cold water in approximately 20 mins with the engine running and keep it hot for up to 24 hours stored in the calorifier tank and sufficiently warm in my cold water storage tank with 'Thermawrap' insulation fitted to my tank. Hope I haven't confused you too much!

[Tim Morton]

thinking of the winter, sorry to put a bit of a downer on it but winters only around the corner. how can i stop 650 litres of water freezing in the back of my van

i have an inverter (120 watt) in the van which i use to keep the trolley battery charged, was thinking of putting a 80 watt heater in the van and powering it off the van battery throught the inverter to keep the water from freezing. the van battery is about 500 amps so was wondering how long would the battery power the heater for till it ran out of charge. if that makes sense

If you run an inverter that feeds a 80Watt heater, roughly speaking you will be drawing 100-120 watts of power from your battery, this is because Inverters are not 100% efficient, especially when running close to their capacity. 120 watts at 12 volts is 10Amps. You say that your van battery is 500amps, do you mean that it is a 500Ah capacity, or that it can supply 500 amps? Just divide your battery's capacity by 10, the amps that the heater/inverter draws. So therefore if your battery's capacity is 120Ah then it would last for 12 hours before the battery would be flat. That would be an ideal situation, in the real world your battery would be flat quite a bit a lot sooner and you would have to push your van to start it !! 

[matt]

funy enough, we were having a similar chat on the DIY forum

think steve m was talking about the heater matrix pipes

[marc al]

   I sit a fan heater with thermostat in the back of my van over night and run it from an extension lead to the garage, I tend to keep it set to 10 degrees, it probably uses alot of electric, but atleast I am warm when I get in my van in the mornings.

   Marc

[jeff1]

If you run an inverter that feeds a 80Watt heater, roughly speaking you will be drawing 100-120 watts of power from your battery, this is because Inverters are not 100% efficient, especially when running close to their capacity. 120 watts at 12 volts is 10Amps. You say that your van battery is 500amps, do you mean that it is a 500Ah capacity, or that it can supply 500 amps? Just divide your battery's capacity by 10, the amps that the heater/inverter draws. So therefore if your battery's capacity is 120Ah then it would last for 12 hours before the battery would be flat. That would be an ideal situation, in the real world your battery would be flat quite a bit a lot sooner and you would have to push your van to start it !! 

Tim You are Spot on

[Tim Morton]

If you run an inverter that feeds a 80Watt heater, roughly speaking you will be drawing 100-120 watts of power from your battery, this is because Inverters are not 100% efficient, especially when running close to their capacity. 120 watts at 12 volts is 10Amps. You say that your van battery is 500amps, do you mean that it is a 500Ah capacity, or that it can supply 500 amps? Just divide your battery's capacity by 10, the amps that the heater/inverter draws. So therefore if your battery's capacity is 120Ah then it would last for 12 hours before the battery would be flat. That would be an ideal situation, in the real world your battery would be flat quite a bit a lot sooner and you would have to push your van to start it !! 

Tim You are Spot on

Thanks Jeff, I had a mis-spent youth soldering my fingers together while shocking myself stupid !!! Electronics was my passion, still interested in it but just not got the time or the space.

Tim

[jeff1]

Thanks Jeff, I had a mis-spent youth soldering my fingers together while shocking myself stupid !!! Electronics was my passion, still interested in it but just not got the time or the space.

Tim

  Same here tim I got my city & guilds 224 in electronics, spent a lot of time and money in my passion for electronics, But like you don't have the time, but there again I suppose I do I spend every evening on the computer, but at least I don't get eletricuted anymore lol

[Tim Morton]

I do I spend every evening on the computer, but at least I don't get eletricuted anymore lol

Until you spill your drink over the crt and watch the 30Kv sparks fly !!     

[Allways Cleaning]

nothing like a loptx to brighten your day:P
regards

[Moderator David@stives]

500 ah is extremely high are you sure ?

[busydaffodil]

night heater could also be a solution.....like lorries have to keep the cabs warm overnight.
I've heard this talked about too.     (thought they sell for about £600, so it is a tad expensive)