Gas-Powered Battery Charger
By Benjamen Johnson
Sure you can run a battery charger with a portable generator, but why not cut out the middle man, especially if you’re off the beaten path where you don’t want to haul around a large generator? This would be especially great for charging up an electric trolling motor battery or camper battery when you’re 150 miles from the nearest outlet.
Weighing in at 26 lbs, this 2.5hp generator can charge a 12V battery up to 55 amps an hour. It uses a 55cc 4-stroke Honda engine to drive a Bosch alternator. The generator consumes about 1/5 of a gallon an hour and has a tank large enough to run for an hour and a half. The panel features an LED readout and a switch to choose between low and high charge rates.
This little generator is made in Australia and it isn’t cheap. It ships with 10 foot leads terminated with alligator clips and runs $1350 AUS, or about $1200 US. If anybody knows of a little gas-powered charger like this that’s made a little closer to North America, let us know in the comments.
Outback Battery Chargers [Christie Engineering]
Outback Battery Chargers [Energy Matters]
September 22nd, 2009 at 8:43 am
Sweetness
September 22nd, 2009 at 9:09 am
Here’s a 2-beer project … round up an old gas mower and some junk yard parts and make something similar yourself for much less money–
http://www.theepicenter.com/tow082099.html
These guys even already sell the brackets and parts.
You’ll want to add a small 12V battery to this so that you don’t burn out the alternator w/o one, but @ $1200 for the unit above, I bet you can round up quite a few junk yard units as replacements.
September 22nd, 2009 at 9:16 am
No idea how good this unit is, but for low $ and 8 hrs run time it’s a consideration…
http://www.heartlandamerica.com/browse/item.asp?product=1000w-factory-gas-generator&PIN=70382&GUID=8B8F638E-15B7-4AF5-8E92-A243826C978B&DL=IVS5#
September 22nd, 2009 at 10:15 am
Gil L. Braverman Says: Sweetness
I think the one submitted by Emis is sweeter by about a kilobuck.
(now if I can just find a B&S 5HP Quantum motor that isn’t doing anything)
I suspect the super cheap import would end up being a waste of money.
September 22nd, 2009 at 10:51 am
The Honda generators already do this.
September 22nd, 2009 at 11:33 am
@Bob:
I can only find 1 generator they sell that does 12V DC charging and it weighs 68lbs.
http://www.hondapowerequipment.com/products/modeldetail.aspx?page=modeldetail§ion=P2GG&modelname=EB3000&modelid=EB3000CKAN
Or am I missing something?
@Emis:
Cool!
September 22nd, 2009 at 11:37 am
Benjamen Johnson Says:
I can only find 1 generator they sell that does 12V DC charging and it weighs 68lbs.
…and would you want to leave a $1600 generator sitting in the back of your truck?
September 22nd, 2009 at 12:29 pm
You need to look harder Honda EU1000iA at 12V - 8A DC output at Dry Weight of 29 lbs and
DC Charging Cord for EU1000, EU2000, EU3000is, EU3000 Handi,
Charge any 12V automotive type battery.
September 22nd, 2009 at 12:45 pm
Leave a generator in the back of the truck? Sure, just bolt it down….or…chain it to something heavy: I usually have a welder in my truck so I just chain smaller things to it.
If you’re going to go the homebrew route and want something truly reliable then consider incorporating something to limit current so you don’t bog down your engine or cook your alternator. A small battery will help to a point but not with extended high-load situations. A task like resurrecting a dead battery bank on a boat or RV can be quite a job for a little alternator.
September 22nd, 2009 at 12:50 pm
@fredb:
Thanks, I was only looking at the summary pages for the generators. I figured that 12V charging would be a feature that you’d want in the summary especially for generators in the play category, but I guess I was wrong.
Am I reading the specs right that even the Honda EU3000iSA only puts out 12A? It’s going to take over 4 times as long to charge a battery as the one I posted.
September 22nd, 2009 at 1:08 pm
Cameron Watt Says:
Leave a generator in the back of the truck? Sure, just bolt it down….or…chain it to something heavy…
You’re right, I have seen plenty of tradesman with generators bolted to the bed (usually truck mechanics), but these guys usually aren’t far from their trucks. I was thinking of the guy who puts his boat in the water for a day of fishing and leaves the truck back at the dock.
…consider incorporating something to limit current so you don’t bog down your engine or cook your alternator…
Any suggestions?
By the by, isn’t your a welder a generator and don’t they have inverter outputs for power tools? Just seems like that would be the case.
September 22nd, 2009 at 2:01 pm
@ Toolhearty
Our truck-mounted Miller Trailblazer welder has a dual generator system so as not to bog down the welder with a parasitic draw. I think the auxilliary out put is something like 10kW - but this isn’t a tool we haul around to charge batteries.
September 22nd, 2009 at 2:39 pm
I know a few people who have used the Chinese $129 special, and it works really well. I’ve seen them on sale for as low as $99 Candian(!). 2-stroke, so a tad noisy, but not that bad. I also know a guy who had his EU2000 stolen. He wasn’t happy.
“…consider incorporating something to limit current so you don’t bog down your engine or cook your alternator…
Any suggestions?”
A lightbulb, or a big resistor.
September 22nd, 2009 at 5:58 pm
The neatest version I saw was made by a guy who had to maintain a fleet scattered around a big complex. He mounted an old alternator to a mini-bike and used the mini-bike engine to drive it. I’m hazy on the details, but I think he drove both the alternator and the rear wheel simultaneously - with no electrical load the alternator didn’t bog down the engine for driving, and when charging he propped up the rear on the kick stand and just let the wheel spin. Pretty simple.
September 22nd, 2009 at 9:46 pm
You’re very unlikely to burn out an alternator. The current limiting device is the design of the alternator. It simply can’t output more current than its rated output.
September 23rd, 2009 at 12:05 am
@Toolhearty: Use an externally regulated alternator and a voltage/current regulator or just a current sensing relay to cut field current when the load gets to be too much. It doesn’t need to be too fancy.
I have auxiliary AC on my machine but it’s not inverted. By the way, I’ve seen old Lincoln Pipeliners that produce DC and run it to a household outlet; if you’re just running a grinder with a universal motor then it’s not an issue.
@fred: I’ve put a few hours on a Trailblazer 302; it’s a good power supply. You can put a fair bit of load on the AC outlets without effecting weld performance. I was doing a handrail job with one and we plugged a Miller Maxstar to the auxilliary power plug; each running 3/32″ electrodes; a dual-operator set on the cheap! It wasn’t too demanding but would never work on my old Hobart; nice though it is.
As for the seperate windings to generate weld and auxiliary power, it’s a great idea. Independant windings solve a couple of problems but if they’re connected to the same engine and a heavy load on one drags its speed down, then the other will be effected….but for most work the issue is purely academic.
@rMeasureOnceCutTwice: The mini-bike idea is the coolest thing I’ve heard of in a while! I’m jealous that I didn’t think of it myself. I used to do maintenance in a distribution centre with a large fleet and I was thinking of wiring in a DC coupler so I could just plug-in a set of jumpers rather than open up the hood each time….never did. If I had heard of the mini-bike idea years ago, I would have used it for sure! …however…It’s bad enough when guys “borrow” tools but that would be one good for a joyride.
@ambush: Not all alternators are created equally. There can be quite a difference between an alternator’s maximum rated output and what it can generate continuously.
September 27th, 2009 at 1:11 am
Small engine plus 1 wire alternator plus small battery is the win!, But seriously why not just carry a jumper box, you can get one for about $29, for $60 you can get one with a nice sized battery in it, a 12 outlet, a flashlight and a compressor, you don’t have to worry about gas going bad, leaking… just charge it a couple times a year.
September 27th, 2009 at 8:17 pm
The jump boxes only work to a point. I have Diesel pickup that will not start with a jump box because the don’t have enough current to get the glow plugs hot and then turn over the engine.