Hey all,

Was reading some great posts of people's good luck of starting their D's in any temperature when plugged in for a while. I often have to visit client offices in the middle of nowhere and parking lots with no plug-ins near by. My car does start pretty well when cold, but below zero can't be a bit scary even after a few glow cycles.

I have a similar to one of these battery jumper units that has a AC inverter built in to it. My question, has anyone used one of these inveters to run their block heater for a short time to warm up before starting? Seems like it would work, even if for a short time.

http://www.autosportcatalog.com/index.cfm?fa=p&pid=3548&cid=43

Could almost bring the block heater cord into the cabin so you don't have to pop the hood.

Thanks!

-m

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Now:
2018 Tesla Model X
1999 S500 Grand Edition 164k
1992 300D 2.5 Turbo 287k
2005 E320 4MATIC wagon
1991 Alfa Romeo 164L 99k (sleeping for a while)

Then: 96 Lincoln TC, 93 Lincoln TC, 87 560 SEL, 87 300 SDL, 80 300D, 89 560 SEC

haven't done that yet but was thinking of buying a schumacher unit for each car.

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currently
[1981 300 td tdidi 165500 dark brown/palamino-Brownie-mine-3k miles of ownership
1983 240d 162+++ Anthricite grey w/ henna red interior and hella lights-wifes car-Red

the above two cars are for sale
and can be seen on the cars for sale thread here. pix also available.


240d-144+ Manilla Yellow w/ palmino interior-greasecar kit-Blondie-the college kids car

23" gt 21 speed still on original tires-still got the nubs
21" khs tandem

I think you will find that a Block Heater draws more current than most inverter supplies can handle. At the very least your battery supply would run down very quickly. Those inverter supplies are really designed for running your laptop or small TV.

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1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown

A 400w inverter could handle the factory block heater, don't even think about the inline heaters, they draw 1000w+.
Said inverter will likely draw 40-45A from the battery. Judging from the size of the unit, I'd guess many of the booster packs are around 10 amp-hours. Ten minutes of block heater operation isn't going to do much other than lead the booster to an early grave.

I know somebody who carries a trolling motor battery down from his apartment and runs the block heater from the inverter for an hour, then lugs the battery back upstairs and puts it on the charger. It works, but it's a lot of effort.

__________________
'79 300SD W116
'86 190E 2.3-16V W201
'92 300D 2.5 W124
'99 E320 4MATIC S210

I don't know where else it can be bought besides canadian tire:
http://www.canadiantire.ca/assortments/product_detail.jsp?FOLDER%3C%3Efolder_id=1408474396670121&PRODUCT%3C%3Eprd_id=845524443271702&ASSORTMENT%3C%3East_id=1408474396670271&bmUID=1134259295398&assortment=primary&fromSearch=true
This is a 1200w inverter with a deep cycle 12 volt battery enclosed. I live in a very cold area and have thought about it. The unit can be mounted in the trunk+the block heater plug routed to it. I'm not going to be driving the car in the winter so I havent actually done this. It seems easy enough to have a 2 switches. One to turn the block heater on and another that charges the unit (run 12v source to trunk) while the car is warmed up+driving. You could also use the 12v charger (included) to charge it from 120v outlet. It also seems easy enough to use a $4 timer typically used for turning on lamps, etc,
and set the timer for 1-2 hours before anticipated starting the car. It is heavy, so not the ideal thing to carry around, but in this area there is also much snow, so it might help to have extra weight in the trunk anyway.
I paid $300 last year-much cheaper than a 1200w inverter and new battery-but not as cheap as they are now-$199. If they were cheaper to ship I'd offer to go to Canada and send them-shipping cost would be too much.

The problem seems to be the inverter here, but why do you need one? You don't want to run a transformer or inductive motor, but just a resistive heater.

You could run the heater on DC if you had the voltage. How about nine or ten 12V gel cells in series, hooked to the heater input? It would not be all that hard to hook them up through some relays that allowed 12V charging with 120V output.

Sure, you would need nine or ten batteries instead of one, but they would each be fairly small.