Pickup Truck as Charger Supply. . .

[klhoard]

I have an F-250 diesel. . . two big batteries up front. Does anyone have experience using these as power supplies for charging big LiPo's at the field? Any gotchas? (other than the obvious -> don't drain them all the way without a buddy to jump start.)
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Specifically, will I need to install a heavy duty alternator? Is there a way to use both batteries either in parallel or separately? Any specific truck battery voltage that you don't let it get below while charging?
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I would prefer a solution that has power outlets at the rear of the truck bed so I don't have to try to charge batteries with the hood open.
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Thanks!!

[Kiwi]

Keith,

If your batteries are in good condition you wont have any problems mate. I have a 2500 RAM with a Cummins in it. YOu can charge BIG LIPO packs off it all day and she still cranks up OK.

If you get a bit worried mate you can start her up while your charging but it wont need it.

Kiwi

[Edge 540]

How many lipos are you charging?

[Kiwi]

Who??

Keith or myself??

I have charged 10 amps for an hour or so into two packs that were running on four big Hackers.

Prolly three charges in a day and no problems.

Good truck batteries are about 100 amp hour batteries. Two of them give you 200 amps for an hour. Say your charging 10 amps max for three hours you will consume 30 amp/hours. Not even a blink inthe capacity of good truck batteries.

[rede2fly]

	Quote: Originally Posted by klhoard
	I have an F-250 diesel. . . two big batteries up front. Does anyone have experience using these as power Any gotchas? Specifically, will I need to install a heavy duty alternator? Is there a way to use both batteries either in parallel or separately? I would prefer a solution that has power outlets at the rear of the truck bed so I don't have to try to charge batteries with the hood open. Thanks!!

ok dude go to your local walmart and buy a battery switch that would be used on a boat. this way you can turn only 1 battery on and use the crap out of it. then when your ready to leave turn it to the other battery to start the motor and then switch it to both batteries for charging and then go to home depot and buy a little 10ga romex. hook up the black to ground. or to any metal part frame,ect and the other to pos on the battery. use wire ties to strap it on the frame along the bottome of the truck (out of sight) get it to the bed of the truck and you now have 12 volts at the bed. tada oh yea ya dont need another alternator

[plane]

I just use the powerport inside the cab. I never really thought about battery drain with 2 batteries. I have been able to charge 3 - 2200mah 3S Lipos at the same time on the Great Planes 4 port Lipo charger. I'm sure I could do all 4 ports but I can't quite fly that much. LOL.

[klhoard]

	Quote: Originally Posted by Kiwi
	. . .<snip> . . I have charged 10 amps for an hour or so into two packs that were running on four big Hackers. . . .<snip>. ..

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Well, that's all I need to know!! Thanks!!
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[Matchless]

Keith, a buddy that works at a truck shop suggested I run a special plug off of the round trailer plug on the back of my Chevy. He commented that I needed to use a multimeter to find the hot wire and then wire from it to a box with either a cigarette adapter style plug or two posts to clamp aligator clips to (dangerous version for obvious reasons.)

The nice thing about the box is that it allows you to remote charge from the vehicle.

Frankly, if you're charging the stuff I last saw you flying, then you could just go from the cigarette lighter.

You've seen my truck, and I charge 2100's all day off of it through the cigarette lighter with a remote box and never have any problems....

[klhoard]

Well, like everything R/C, I've found my LiPo's getting bigger and bigger. I have already ran a 12-gauge wire to the back of the bed and have it connected to a couple cigarrette power outlets in the bed with a 30 amp fuse. I'm considering expanding my outlet capacity so I can run more than one charger at a time while flying.
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My LiPo's are up to 2100Mah now, but I could easily see myself moving up to the 5000 Mah F3A packs in a couple years. If I could avoid having to maintain / drag out to the field a Honda generator for charging, that would be great.
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Does anyone know if the batteries are connected in series or parallel in the F-250?
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[klhoard]

	Quote: Originally Posted by Matchless
	Keith, a buddy that works at a truck shop suggested I run a special plug off of the round trailer plug on the back of my Chevy. . .<snip>....

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Did he say how many amp you can draw (safely) thru that plug?
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[Edge 540]

If you are worried just go buy a lawn mower battery. Mine was $30 and has 320 amps or 270 cold. I bought it and used it most of the summer before I bothered recharging it. If you are running a lot if big lipos you'd still be good for a weekend at least. We used one to run 2 laptops, a tv, 3 chargers, and both telemetry and video receivers through an inverter all afternoon.

[Kiwi]

Most pickups have a 20 amp fuse on the cigar lighter circuit. You can easily drop a 30 amp fuse in it if you like but 30 amps continuous might get a few things way too hot. 20 amps will do a heck of a big battery pack.

I have used motor bike batteries before as well and they last a weekend without too much trouble on the likes of 2100 packs.

If your going for those 10S5P 6000 MaH packs then I think you might need to look hard at what you use to recharge them with. I need to do the numbers to see what you could actually drag out of a battery with these.

[klhoard]

I called my local truck shop and confirmed that the batteries are wired in parallel. . . so I'm not concerned about hooking up 2 or 3 chargers simultaneously at the field.
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Thanks for the help guys!!
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[Marty]

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[toprudder]

If it were me and I were going to make a regular habit out of charging large lipos, I would do what someone suggested and buy a battery disconnect (knife-blade type, for instance) so I could disconnect one battery and use that one to charge from. Also, once the 12v battery dies, I would also seriously consider getting a deep-cycle type battery. A car battery does not last as long when used in a deep-cycle type application, which lipo charging would tend to mimick.

Also, driving too/from the field might not fully charge a depleted battery, that could take several hours to fully top off. Of course, if you drive the vehicle several times between trips to the field, that would probably do it.

I don't think there is a need for a high output alternator. The initial high-rate charge does not last very long after cranking, after that the alternator charges at a constant voltage and the current tapers off.

I just bought a couple of 15w solar panels from Northern Tool. They put out about an amp each, not enough to charge anything but very small lipos, but they do keep my portable battery topped of enough between charging lipos so I don't have to worry about depleting my charge battery. Of course, this requires sunlight....

Bob R.