First the background music: Sometimes I get to work in locations that have no power available. I’m pretty adept at “borrowing”, as Gamble Rodgers said: ‘it’s easier to get forgiveness than permission’, power from any source within a few hundred feet of where I need it but even this is not available. I have access to a generator but it is heavy, cantankerous and seldom at hand when I find out the site has no power. I carry a collection of manual tools, including a brace and bits and a hand saw, but these can make for a long and tiring day.
I looked into getting a small suitcase style generator, around 1800 watt, but they want an arm and a leg. Theft might also be a problem. Being gas fired I can’t put the unit, if I’m smart (As if someone accused me of being smart.), in the cab of the truck. I guess a eye bolt and stout chain would work but it would be more time, trouble and expense.
After noodling this I came upon the idea of installing an inverter to convert the 12v DC supplied by the trucks alternator and battery to 120v AC used by the power tools. I’m thinking this unit would do everything I need it to do, it is just a bit over sized to last a bit longer:
http://www.donrowe.com/inverters/vector_1200.html
My truck, a ’97” Ford Ranger, has a 95A alternator. With the battery to take up the slack it should be able to keep up. I would only use the inverter with the engine running. There is advice to not mount the inverter in the engine compartment. Overheating, fumes, moisture are all cited.
I am leaning toward ignoring this advice. The reasons being: I will run it only with the truck stopped, engine running and hood open. I intend to fashion a weatherproof cover out of tarp material to keep any dirt and water off the unit as I drive. This cover would, of course, be removed prior to using the inverter.
The advantage of this strategy would be that the power leads from the battery would be short, I have, I think I have, room next to the brake reservoir and I have precious few other good places to install it. Under and behind the seats are taken.
OK. Now that you know the tune on to the dance:
1) Does anyone have any experience, real or imagined, with such an installation?
2) Would a second battery, I think I might just be able to shoehorn in one, be a good idea? Does anyone have a name of a good brand of battery isolator and charge controller?
3) Is an inverter a good alternative given that a 8.3A , 1000 watt load is the most I will need? This will run my hammer drill or a small trim saw or some combination of lights and a lesser drill.
4) Am I fooling myself installing it in a location I have been warned against?
5) Does anyone have any tips, ideas, suggestions, abuse or insubordination to offer on this general subject?
Replies
I have an inverter in my Dakota. Its mounted on the drive hump under the dash. I made a plywood box that it sets in that also holds a tool battery charger. I'd have to go outside and look at what the power rating is and its dark out there. I've run a worm gear on it, but it cuts out if the going gets rough. I've mostly used it to pull a grinder and charge batteries. Last winter when we had an ice storm and were without electricity for nine days, I ran the big screen tv and lights and battery chargers for my cordless sawzall (which was all I had to cut firewood with for heat in the fireplace). I would vote for putting it in the cab for the cordless battery charging. Your usage may be different. I've seen them mounted under the hood. I can't picture the inside of a ranger, but it can't be a whole lot smaller than a dakota.
Getting the inverter, and especially a second battery to fit, might involve me buying a bigger hammer and an expanded vocabulary.
Conformal coat & salvaged fan.
Biggest problems with some of the commercial (vs true industrial or aerospace) electronics is the lack of conformal coating on the circuit boards. As a mater of course, every item I buy gets an acrylic or paralene spray job of the circuit board, from garage door openers to VCRs. For easy consumer availability, simple clear polyurethane spray cans also work well for this. This will at least keep the moisture from shorting out the boards. Temperature is a whole 'nother matter, see if the spec sheet for your inverter allows for operation in 180F ambient, probably not due to the recommendations earlier cited. You can always salvage a 12 Vdc fan from an old computer and add it to the cooling airflow path of the inverter for better hot temp performance/survivabillity.
I have easy access to a pair of 4" 12v fans and was thinking that it would be easy to mount them to blow onto the inverter casing that is used as a heat sink for the power transistors. The poly spray is a good idea but I would need to mask off any surfaces that get hot to allow them to breath, cool properly.
Of course this takes up more room. I might end up with the engine in the bed. I guess that means the lumber goes in the passenger seat.
Don't bother to mask, any incidental poly overspray onto the heat sinks would have minimal effect on the cooling capabilities of the heat sink, since most of the temperature drop is across the surface boundary layer with the air. The fans would do a good job. Take a look at the following 2 links, there are tutorials buried in the vendor's web sites somewhere (didn't try to dig them out) about 'how to' cool electronics with fans, and the Aavid site has a calculation worksheet also.
I'm sure you can build a sheet metal shroud somewhere in your engine compartment or under the dash on passenger side for both airflow and/or splash protection, and with 2 additional fans, keep it cool. The only useful engineering info on the inverter you are considering in the web site was that it is 90% efficient, so you only have to get rid of 100 W waste heat with the fans.
edit: add links
http://www.comairrotron.com/DCFans/Flight90.htm
http://www.aavidthermalloy.com/
Edited 10/8/2003 6:50:58 AM ET by JUNKHOUND
think 1 of the new gmc trucks comes with an inverter with the plug near the tailgate, suitable for tools
bobl Volo, non valeo
Now if i can just find a GMC parked in a dark spot...
I have a GMC parked in my "dark" driveway, unlocked, keys in it.
Oh, did I mention it doesn't run. Please bring tow truck.
Sounds like you have a very secure anti-theft device. It is pretty hard to sneak around with a tow truck in your pocket. There area few cases of thieves driving tow trucks but why would they steal a truck that doesn't run? On the other hand some thieves would steal a red hot stove.
Way back in high school a friend drove a Pinto. The starter gave out and he, typical of the neighborhood, had no money for another. Luckily he had a standard so he could, as long as the road was flat or a down slope, push start it by pushing with the door open, hop in and quickly shift it into drive. The Pinto was so light that he could do this regularly by himself even though he was nothing like in shape. He used to park his car with windows open and the key glued in place, you wouldn't want the key to get stolen.
He regularly got report about people getting into it but no one ever stole the car. I guess thieves are too lazy. If they had to work to steal a Pinto they could more easily get a job and make real money.
I was originally thinking that I had to rush to buy the inverter I mentioned at a sale price. Now I find out they, DonRowe.com, extended the sale for two weeks. Why? I talked to a local store that carries the Vector line of inverters and found they only had 350w and smaller ones left in stock. When I asked if they had or could order larger units they said no. The lady knew that all of the larger units had been recalled and removed from the order list but she didn't know why.
Are the larger, 1000w and 1200w, inverters made by Vector, they go by the MAXX title, defective? I would hate to buy a defective unit or, even worse, smoke my truck. Has anyone heard anything about these units? Any ideas?
Just checked Google w/ "Recall Vector" There is a recall:
http://www.cpsc.gov/cpscpub/prerel/prhtml02/02095.html
But it does not seem to cover the model/s I'm interested in. It is only units with a GFI on the output. No such nicety on what I'm thinking about. I didn't want a GFI. GFIs are delicate and I would rather plug one of my own in so it can be replaced easily when it fails.
has anyone heard about any other problems with these units? Especially this brand?