I've installed dual 6v golf cart batteries, a 2300 watt inverter, and two 100 Watt solar panels on my travel trailer. Sometimes if my campsite is shaded after a few days my batteries can't handle making my coffee with my 1500 Watt Keurig. My temporary solution the other day was to idle my truck and run my jumpers to the batteries to make my coffee. Only took about 4 minutes of idling.My question is does anyone do this to charge their batteries completely? I have a F-150 Ecoboost. How much current can I charge in to the batteries at idle? How long would this take? My thinking is that my truck is honestly just as quiet as a Honda 2000 and I'd only need to do this a couple of times a year. If this works well maybe I'll do some nice electrical work to avoid using jumper cables.

Some people do it. Don't see it causing much harm. I wouldn't idle my truck for much more than 25 minutes at a time though.

at idle most charging systems can only produce 30 percent Max. you are mostly using the battery in the truck to run your coffee pot.if you could run the truck engine at 1,500 to 2,000 then you would be charging your trailer batteries.

first of all , why do you need to use a keruig coffee maker ...have you ever used a 'percolator 'coffee maker on your gas stove ... thats what I use when I camp with out power...camping does not always require electricity...imop

Other than putting one heck of a load on your alternator by asking it to do something it was not designed for, I don't think you are getting much accomplished. As the previous poster mentioned, @ idle not much charging is going on. I guess that in an emergency situation or in a pinch, it would be decent. But for something like this to be employed as habit, you are asking a lot from your truck's electrical system. Also, someone who knows cars more than me might contend that connecting and disconnecting dissimilar electrical circuits is bad for the truck's computers. I don't know how much more robust computers in vehicles are now when compared to one 10 years ago, I do know that in the past, it was always frowned upon from the mechanics that I spoke with.

When boondocking I connect a battery charger to my trailer batteries (2 x 12V in parallel) powered by a 400W inverter from a cig lighter in the truck for keeping the batteries topped off. We do not use an inverter to create 120V for anything in the trailer so we are very frugal with battery draw. A tea kettle is used to boil water for instant coffee, tea, & cocoa.I now have a quiet 2KW generator the wife can use for her hair dryer rather than borrow power from a fellow camper in a motorhome so this winter will be different. I need 120v to inflate an airbed couch daily when guests bunk with us.

Using Truck Alternator to Charge House Batteries

jaycocreek
Explorer II
May 09, 2014
Hooking up the truck to the camper batteries via jumper cables is the way the Forest Service crews keep there camper batteries charged in these parts.

Works just dandy!
AH64ID
Explorer
May 09, 2014
Hybridhunter wrote:
ah64id wrote:
Even with jumper cables I doubt you get the power you need to make it worthwhile in fuel and time.

But an ammeter would tell the story.

An all night ir conditioner run verified it works. 8hrs drawing 700 watts. That was through 4 ga booster cables.

Works and worthwhile are not always the same.

Is that 700w of AC after inverting? If so that is closer to 70A of DC pre-inverting and I don't think you will get that at idle and if you do the alternator isn't going to be happy with that output at low rpms for 8 hours.
pianotuna
Nomad III
May 09, 2014
Hi,

700 watts represents about 53 amps of load on the alternator. I'd prefer to not push it quite that hard.
John___Angela
Explorer
May 09, 2014
Nvr2loud wrote:
harley4275 wrote:
first of all , why do you need to use a keruig coffee maker ...have you ever used a 'percolator 'coffee maker on your gas stove ... thats what I use when I camp with out power...camping does not always require electricity...imop

I look forward to camping just for the percolator coffee... it just seems so much nicer on a chilly morning outside to have a 'roughing-it' coffee!

Well, it aint campin without the kuerig. :) Going out tomorrow for the weekend and it was first on our make sure its in there list. :)
Hybridhunter
Explorer
May 08, 2014
RJCorazza wrote:
but IMHO show it's a viable option to eek out a day or two of boondocking. Really a better method would be to use a small 1000w generator and either the trailers converter or a 40a automotive battery charger.

Thing is you then have to carry an extra charger, a genset, gas etc. And as soon as you go up in altitude, things act up. Our 1200 watt genny was near useless at 8000+ feet. I am looking forward to my next trip without all the hassle. Had I save a $200 and not bought a genset, I would be ahead.
To each his own, but it can work, as you said!
Hybridhunter
Explorer
May 08, 2014
ah64id wrote:
Even with jumper cables I doubt you get the power you need to make it worthwhile in fuel and time.

But an ammeter would tell the story.

An all night ir conditioner run verified it works. 8hrs drawing 700 watts. That was through 4 ga booster cables.
Hybridhunter
Explorer
May 08, 2014
pianotuna wrote:
Hi Hybridhunter,

What inverter were you using? Thanks in advance.

Hybridhunter wrote:
The alternator has such high output at low rpm, I was able to run our window AC off of it (via our hard wired inverter)all night, burning about 2ltrs an hour of fuel.

Hmmm. I believe it's a Xantrex MSW 1500watter? Not positive on that though. Hardwired, and due to a design overhaul, its 12'from the battery bank. Wired with parallel 2ga I believe.

In the Toyota, we ran the OEM inverter, and plugged in the (different camper) OEM converter. That was a slick setup, just plug and play.
(Otherwise the Tacoma was a terrible all around vehicle)
AH64ID
Explorer
May 08, 2014
Even with jumper cables I doubt you get the power you need to make it worthwhile in fuel and time.

But an ammeter would tell the story.
Nvr2loud
Explorer II
May 08, 2014
harley4275 wrote:
first of all , why do you need to use a keruig coffee maker ...have you ever used a 'percolator 'coffee maker on your gas stove ... thats what I use when I camp with out power...camping does not always require electricity...imop

I look forward to camping just for the percolator coffee... it just seems so much nicer on a chilly morning outside to have a 'roughing-it' coffee!
RJCorazza
Explorer
May 08, 2014
I would not hesitate to occasionally boost house batteries via large cables from my truck alternator. As far as alternator speed and output, my F250 155a alternator is capable of providing about 90 amps at 650 engine rpm (2000 rpm alternator). I hacked into the PTO harness and have a high idle switch set at 1450 rpm, which would provide about 150a of charging amps at 80 deg. I didn't measure the current, but got my numbers from Ford's alternator specs for the 6.2l 155a alternator output curve.
To get my modest 230ah bank from 50% to 80% at idle is going to require running the truck for about an hour, 30 min at high idle. That last 20% to 100% is not feasible. These are ballpark numbers - but IMHO show it's a viable option to eek out a day or two of boondocking. Really a better method would be to use a small 1000w generator and either the trailers converter or a 40a automotive battery charger.