Need some APU help........

Most of them little heaters are 1500 watts. Even the tiny fan ones are which is more than enough for a vehicle.
You are going to have to change the whole set up.
I would recommend the Cobra CPI 1550 and you'll need 3-4 batteries in series to run 8 hours. Then you need a way to recharge the batteries. And you don't want the batteries inside the vehicle while it's charging for the gasses.

If it's a pickup, you should have room for 3-4 batteries under the hood. I would seek professional help on the installation. Since you want the inverter leads kept to a minimum, I would put it under the glove box area. Then run an extension cord to the back or just keep the heater up front near the inverter. This way the batteries can recharge as you are driving.

If it's more of a temporary thing and you are charging the batteries at home. Do like you were but hook all the batteries positive to positive to each other, then to the inverter and negative to negative to each other, then to the inverter. Deep cycle marine batteries are even better. You might get by with two of them. You could always add a third.

A little fan bathroom heater on low will keep you toasty if not make you crack open a window.

 

Wabasto's are listed for $895 brand new!! They will cook you out of the cab if you turn them up a bit!! Only take a tiny bit of fuel, a buddy used a gallon jug to run his before he got it installed completely, ran all night with soem left over.

Bill

 

Buy an Electro-Warmth mattress pad... I've been using one since the 70's and it was my only way of keeping warm while sleeping until I bought my ESPAR three years ago. Draws about 3 amps... will fry you out if you turn it past 4....

 

you do silly things!
really!

wanna heat? I'd recomend you Webasto At2000-3500, may be AT5000, Ebespaher D3LC ore any other diesel park heater. Use a quater ore a half gallon of diesel per night!

Safe, self ajusting cabine temperature.

12V versians are availble. Easy to find on EU JYs. They sell them for everyone, they send them with post, UPS, DHL... no problem!

 

Formula.... Watts divided by Volts = Amperage draw.

 

also these cheaper inverters are a modified sine wave inverter not a true sine wave inverter you will always get a small amount of buzzing out of it the mods are about 85% efficient versus the trues which are about 60 % efficient which means a mod inverter will consume 100% energy and only put out 85% the other 15 % is dissipated as heat so if you have a 1500 watt modified sine wave inverter it will consume 1775 watts on the input side....

a 1500 watt true sine wave inverter will put out 60% power the other 40% is heat which means it will consume about 2100 watts

now to run the mod sine wave inverter you will need roughly 145 continous amps to feed it at full power.. does your apu have a alternator that size much less the line feeding the batteries needs to be about a 4 gauge min if it s a 6 foot run to run that inverter at full power.. and note you will get a buz sound from just about everything you run on a mod sine inverter.... unless it has a very well built power filtering side

also a true sine wave inverter is about 4 times the price as a mod sine wave inverter as well..

sorry im jabbering but just what i know and figured i would share it with ya...

 

Yeah a diesel bunk heater is much better. The other jury rigged set up you might end up catching on fire.

You need multiple batteries. One wouldn't last all night with an inverter. You could idle to charge the batteries, lol.