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what effect would running an 800 watt device on a 12 volt system?


bushwhacker

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Toying with the idea of using an 800 watt 12 volt small heater to use on really cold days. I have a 300 watt at the minute and heat wise the jury is still out with more testing required. As we all know LR diesels take for ever to get hot and with my short journey's it's not going to happen.

Also noticed you can buy Planer heaters for £112 odd on Ebay but are they any good and the real McCoy?

Please don't hang me out to dry it's too  near Xmas.

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I don't know what it would do to a battery long term but they are not designed to do this. If you only do short journies you will be having to charge it up regularly from a mains powered charger. 

I have 3 alternative ideas for consideration:

(1) fit a lesuire battery with split charge system to power your 12v heater and you don't run the risk of draining the main starter battery leaving you stranded. 

(2) If parked on a drive in reach of a mains Power Point (hopefully you are as you are going to have to plug a charger in regularly for plan A) , put a mains powered heater in the vehicle and turn it on 10 minutes before you leave. 

(3) look into fitting a diesel powered heater like a Webasto or similar. 

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800w/12v = 66.7 amps draw which is more than your alternator can provide. Engine-off it'll flatten your battery in less than 2 hours.

By comparison, a SMALL Eberspacher (D1LC) draws 2.5A and creates 2200W of heat, the larger ones make 5000W for not much more draw and a bit more diesel.

I have a 1kW electric heater in my 109 in the garage and indoors it can just about take the edge off on a chilly day.

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I've got a mains powered water heater that sits in-line on the heater hose (can't recall the brand offhand), you just plug it in in the morning or have on a timer and it pumps hot water round the system. 

Never got round to fitting it though since I put the waeco seat heaters in which are a game changer and make more difference than slightly warmer air from the vents which is always fighting the draughts - only take a couple of minutes to get toasty. They make two types, one a simple zig zag wire element, the other is carbon fibre mesh - have tried both types,  wire element are good, carbon mesh are amazing - not expensive either.  

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My 90TD5 doesn't heat up at all on my commute to work as it's all town driving and quite stop-start. I looked at new and second hand Webasto and Planars but it was going to be about £600 minimum for one of the Planar kits. I therefore took the leap of faith into the Chinese ones and, so far so good (touch wood). Takes less than 5 minutes in the morning to heat the car up. My only criticisms are it's quite a bit bigger than a Webasto and i'm yet to hide it properly, and it's a bit difficult to control the heat output. The temp control only controls the speed of airflow so it does get quite hot in the cabin after a while. Rather that than too cold though! It cost me £160 all in and took about 2 hours to fit.

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2nd hand Eberspachers & Webastos can be had for ~£150 ish, just need to make sure you get the fuel pump & any controllers / relay boxes with them.

I'd still take a 2nd hand German heater over a brand new Chinese one although I do know a couple of people with them who say they work well enough.

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If you can plug into mains where you are parked, you can use a real heater (2000 W) or so with a cord run out to the grill.  Plug it in and use a timer to turn on half an hour before you leave.  This is the budget preheating system.

Beyond that the diesel fired variety is the best choice, but they are a lot of work to fit properly.

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Hi all thanks for all the info.  I think my options are.

1 Diesel heater cheap new (expensive ones not an option)

2 House type plug in heater on before a journey. This heat disappears almost as soon as you turn the heater off.

3 Second battery for heating maybe running on a second alternator 100amp.

4 Carry on with the hat, warm coat and gloves.

Diesel heater has to be the way so I must start saving.

Thanks again guys. 🥶

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For "early-morning starts" in my 90TD5 for the last couple of decades I've used a 3Kw mains-powered fan-heater sat in the passenger footwell.

The door-seals in a Defender are slack-enough to accomodate the cable; I've got a timeswitch set to activate the heater an hour before my expected need-to-drive time.

It's neat to always be able to get into an ice-free car which is nice-and-toasty inside. Just remember to unplug before driving away!

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15 hours ago, FridgeFreezer said:

2nd hand Eberspachers & Webastos can be had for ~£150 ish, just need to make sure you get the fuel pump & any controllers / relay boxes with them.

I'd still take a 2nd hand German heater over a brand new Chinese one although I do know a couple of people with them who say they work well enough.

You might get a decent Webasto during the summer months for £150 but i haven't seen one go for less than  £250 incomplete on ebay recently. Must be a few LR owners out there starting to feel the cold!

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I'm quite amazed at some of the comments about their Defender not warming up even on a short drive. I have a 19J and don't drive it hard. My cooling system is thoroughy clean throughout, heater controls properly adjusted and there is only a gentle breeze when I drive rather than a gale through all of the gaps. As soon as I have left my village (about 2/3 of a mile) I am starting to get warm air. By the time I have covered 2 miles I have to turn the fan down to position 1 as I'm starting to get too warm even on a frosty morning.

If you spend some time ensuring the matrix and the rest of the cooling system are as clean as possible internally, thermostat is working as it should and then all of the controls are moving correctly I don't think you should have a cold cab after even a short drive. Afterall, most of your fuel is being converted into waste heat :wacko:

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Personally, I think you will be amazed at the difference you can make by just spending a little money on some new coolant and then just ensuring everything works properly by making a few adjustments here and there until it works as designed. No need at this stage to be buying heaters of any variety until you know what you have already works properly.

Edited by monkie
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35 minutes ago, monkie said:

I'm quite amazed at some of the comments about their Defender not warming up even on a short drive. I have a 19J and don't drive it hard. My cooling system is thoroughy clean throughout, heater controls properly adjusted and there is only a gentle breeze when I drive rather than a gale through all of the gaps. As soon as I have left my village (about 2/3 of a mile) I am starting to get warm air. By the time I have covered 2 miles I have to turn the fan down to position 1 as I'm starting to get too warm even on a frosty morning.

If you spend some time ensuring the matrix and the rest of the cooling system are as clean as possible internally, thermostat is working as it should and then all of the controls are moving correctly I don't think you should have a cold cab after even a short drive. Afterall, most of your fuel is being converted into waste heat :wacko:

The heater in my missus’s 90 TD5 soon produces warm air from a cold start, but it just doesn’t heat the cab very much. The door seals are all good, and there’s no leaks.

The heater in my 110 SW is better, in that it seems to output more air. I checked the heater in the 90 and it all looks fine, but the 110 is definitely better for some reason.

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6 minutes ago, Lightning said:

The heater in my missus’s 90 TD5 soon produces warm air from a cold start, but it just doesn’t heat the cab very much. The door seals are all good, and there’s no leaks.

The heater in my 110 SW is better, in that it seems to output more air. I checked the heater in the 90 and it all looks fine, but the 110 is definitely better for some reason.

Could it be down to the extra work the engine is doing to lug around the extra 20 inches of wheel base?

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i have a new matrix, new thermostat, fresh coolant, adjusted heater controls and it still struggles with heat. it's a good bit colder up here in the mornings, probably about 2C every morning and that certainly doesn't help. Chinese heat has fixed the problem for me so i'm a convert.

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22 minutes ago, paime said:

i have a new matrix, new thermostat, fresh coolant, adjusted heater controls and it still struggles with heat. it's a good bit colder up here in the mornings, probably about 2C every morning and that certainly doesn't help. Chinese heat has fixed the problem for me so i'm a convert.

This maybe quite ignorant of me and I am willing to accept my knowledge of diesel fired heaters is in it's infancy - the words "Chinese" and "heat" put together in this context make me think 😬.......

 

....sorry but I can't help it!🤪

 

90burn2.jpg

Edited by monkie
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I have watched a few youtube installs for the chinese heaters and all are positive so far. There was one guy who had his heater installed from last winter didn't use it over the summer fired it up a couple of weeks ago and it is still ok for him. UK guy even cut the head of one and ran it for test purposes, it did flame out eventually but it let him see what was happening in the burn chamber.

Everyone should err on the side of caution with this sort of kit and keep a good fire extinguisher real handy.

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43 minutes ago, monkie said:

This maybe quite ignorant of me and I am willing to accept my knowledge of diesel fired heaters is in it's infancy - the words "Chinese" and "heat" put together in this context make me think 😬.......

 

....sorry but I can't help it!🤪

 

90burn2.jpg

I'll admit that image is never far from my mind either! There are now quite a few forums and postings by people who have them installed. The quality control process is my main concern with it rather than the design. If it's been built to it's design spec then there shouldn't be any issues. If it hasn't been built to it's design spec however....

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11 minutes ago, paime said:

I'll admit that image is never far from my mind either! There are now quite a few forums and postings by people who have them installed. The quality control process is my main concern with it rather than the design. If it's been built to it's design spec then there shouldn't be any issues. If it hasn't been built to it's design spec however....

I'd agree with that. Also a dodgy installation of even a premium product could all end in a disaster!

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2 hours ago, monkie said:

This maybe quite ignorant of me and I am willing to accept my knowledge of diesel fired heaters is in it's infancy - the words "Chinese" and "heat" put together in this context make me think 😬.......

 

....sorry but I can't help it!🤪

 

 

chinese heater in my van has done its job to the point im considering fitting one in my 110DC,

 

28C inside my van at a very wet walters arena was definetly welcome after a day in the rain

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