Battery Vehicle Society

Hi Chris
Try these
http://www.redforge.co.uk/products/cabheaters.asp

Cheers...but what if i ran one of these:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :middle:uk

Its a 240v 1500W AC heater element, but I can run it at 96v DC. Does this mean it will effectively be a (96/240)*1500 heater = 600W?

Basically, will it work, will it give out some heat?

Hi Chris

Ohms Law !! You would be pulling 15.625 amps at 96Volt with a resistance of 6.144 ohms
Mind those batteries !!! Lot of power just to de-mist a windscreen

geekygrilli wrote:Cheers...but what if i ran one of these:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :middle:uk

Its a 240v 1500W AC heater element, but I can run it at 96v DC. Does this mean it will effectively be a (96/240)*1500 heater = 600W?

Basically, will it work, will it give out some heat?

No, it won't work.

These heater cores use a PTC (positive temperature coefficient) ceramic element bonded to aluminium fins. The resistance rises very steeply with temperature.

They're designed to reach a specific temperature (generally 180F) and self regulate. This makes them very safe. Even with no airflow, they won't overheat. The low peak temperature means the don't smell when contaminated with damp/dust.

They only work over a limited voltage range, so you need the 110v version (try ebay.com) at least. Canadian Electric vehicles have 72v (nominal) modules available which might be better for your 96 volt system.

Cheers guys...I was so wrong its embaressing! My calcs based on constant resistance, of 38.4 Ohms mean that at 96v the current draw would be 2.5A and Power 240W...

Will stick with the 12v heaters for now.

Or if you want to totally cook yourself try one of these

http://cgi.ebay.co.uk/eberspacher-cab-h ... 0198534399

ChrisB

This evening, among other things, I fitted 2 x 12v 200W Cermaic heaters wired in parallel into the original matrix area to see what the heat output was like...

I was pleasenty surprised, as there was more than a hint of warm air coming through, maybe just enough de-mist the screen. More heat is gained by increasing the air flow.

The ceramic heaters are self regulating, like the ones from Canadian EV, and there is plenty of space within the original matrix area to fit 7 or 8 and run at 96v in series, giving about 1600W of heat.

Anyone have any opinions on this, though, before I get more heaters?

Just thought you might like to know I hate working on cars! I spent 3 hours last night upside down in the driver's footwell, getting blinded by my lead lamp and scraping my knuckles on absolutely everything.

All I wanted to do was find a suitible hole btwn the the passenger compartment and the engine bay, but I got a bit sidetracked and then wanted to remove the redundant clutch pedal, which meant removing the whole pedal box, and to do that I needed to remove the strg lower joint, which in turn required the whole strg column to come off...

And after all that I still don't have a hole for my wires, or skin on my knuckles.

In some strange way, its all good fun, though!

From memory the legal requirement is only that you provide "adequate-demisting" or words to that effect:

In some 50's cars adequate demisting was a duster!

From that point of view the best solution would be a quick clear windscreen (if avaialable for your car) and a coat!

I would consider carefully your proposed driving/charging regime.....In many ways the best solution is a big 240V heater/demister that warms and clears the car while its on charge and a small (low battery draw) arrangement (fan only?) that keeps the screen clear when driving. The car iteself is likely to stay warm for longer than the battery charge will hold out........of course this scheme falls down if you park for a long time then drive again without charging.

110V heaters are not hard to get in the UK. Remember most UK industrial sites are required to use 110V for safety reasons. The only problem is that most available heaters will be made for industrial use so may be a bit expensive. See for example http://www.airconditioningdirect.com/ac ... 33224ce0ca

Hope this helps
Regards
Geoff

Thats it, thats what I want, exactly! And its 'cheap' too. Everything I've been looking at is £160 - £200, because that are industrial.

And the 240v heater whilst on charge, though not the most environmentally friendly solution, seems like a great idea. I'll just stick it on a timer... I go to work the same time each day, so it shouldn't be a problem. And my journey is only 25 minutes.

So possibly, a 240v heater on a thermostatand timer for pre-heat, and the two small 12v ceramic heaters I have could be enough. The 240v heater can stay in the car somewhere, so I can run it at work if necessary.

This is great, its all coming together nicely now.

Cheers for the ideas!