Forum Discussion
67 Replies
- BendExplorer
landyacht318 wrote:
Idling to recharge is wasteful.
But, If one employs thick copper between distant battery and alternator, 50 to 80% can be achieved fairly quickly, IF the alternator can output 60+ amps at Idle without damage from overheating, and If the voltage regulator is seeking mid 14's instead of 13.6v. 80% to 100% takes hours no matter what.
Lots of 'If's' up there.
Use a 500 amp winch connector and 2awg cable, disconnect when camping, no Diode/isolator/solenoid required:
...
I was able to get 100+ amps at idle into a single group31 50% depleted lifeline AGM battery through 2awg cable, that 500 amp winch connector and about 25 feet total circuit length from alternator to Lifeline's posts.
The '160 amp' alternator quickly heated to 220F and output then maxed out at 86 amps while voltage was still in the mid 13's, indicating the battery could have accepted higher amps.WyoTraveler wrote:
old guy wrote:
at a lot of star parties in Oregon the forest service controls the use of generators. so many do charge their batteries by running the tow vehicles. no other way to do it on the years that genns are not allowed
Think that is differnt though. When I had a TT and was dry camping I would turn my truck around and charge my house batteries using jumper cables directly to the battery in the PU in the morning before I got a solar panel.
If you REALLY want to commit to this as plan “B” or plan "C" for battery charging or a DC high amp source for a large inverter, MEX has already provided the best solution. The fuel cost of using the TV as a power source is bwtn .5-.75 gal per hour.
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26303825/srt/pa/pging/1/page/1
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28015670.cfm
I'm currently building one and will report on it this coming summer. - WyoTravelerExplorer
old guy wrote:
at a lot of star parties in Oregon the forest service controls the use of generators. so many do charge their batteries by running the tow vehicles. no other way to do it on the years that genns are not allowed
Think that is differnt though. When I had a TT and was dry camping I would turn my truck around and charge my house batteries using jumper cables directly to the battery in the PU in the morning before I got a solar panel. - fitznjExplorerI tried this once in a pinch when I was boondocking.
I ran the TV for 3 hours and had just enough electricity
for one evening of light.
Bought a Yamaha generator and I had to run it 4-5 hours/day to top up the
batteries. I changed over to a 165?W solar panel and this is enough to replenish the batteries - even during a cloudy day. - Golden_HVACExplorer
Flatfive wrote:
Okay. Got it. That's what I thought. We have switched to LED lights. We'll probably get a portable solar set-up soon.
What is WyoTraveler talking about: " a diode and 10 ft of wire"?
If you have a motorhome, and tow a car, sometimes the towed car battery can go dead while towing it. So running some wire to the towed car will charge it's battery while towing. Really has nothing to do with your situation, and will not keep your car battery full while you are towing a trailer with a pickup
LED lights are great. However your RV will still consume 35 AH daily to run the CO and propane detectors, refrigerator. The lights, furnace and things like a inverter to run a TV or laptop will consume even more power.
The water pump is actually insignificant, it will pump 2 GPM for 1 hour while consuming 7 amp hours, and empty a 120 gallon tank for 7 AH.
What you really need if you like dry camping is a 140 watt solar panel - it will replace around 45 AH daily per panel. This place had them for $229 a few weeks ago, with aluminum frame, and 12 volt nominal output (actually about 22 volts open circuit, but considered 14 volts under load). Add a PWM controller rated at about 20 amps, and you are set.
Some grey UV rated wire from Home Depot and 4 each 6" long 2" angle aluminum brackets to mount each panel to the roof, some rubber roof sealant to seal all the screw holes, you are set.
Run the wire down the back of the refrigerator, through the roof vent into that space, to the controller, then to the battery. I am using #10 wire for a pair of 120 watt panels, and another run of #10 wire for a pair of 45 watt and a single 75 watt panel.
While #10 wire is rated at 30 amps maximum in house use, the 15 amps that I am running through my run is considered a high load for this small of wire when run in DC applications, and larger wire might be recommended, but still I am charged by 3 pm, so I don't care to much about voltage drop, as it is working fine for me, full timing over 4 years.. .
SUnElec.com
If I where to run the truck engine while charging the RV battery, I would first hook up jumper cables from the truck to the RV battery and let it charge for say 15 minutes. Then start the engine, and let it idle for say 15 minutes and then shut it off for another 15 minutes - cables still hooked up. It will suck come more amps from the truck batteries, but not enough to draw them down to far. After 15 minutes, then idle the truck again for 15 minutes, and after shutting it off, disconnect the jumper cables within 10 minutes, so the battery in the truck stay full.
As stated above, if the alternator is rated at 160 amps, once warmed up, the output will go way down. His ability to charge at 86 amps indicated he was running very large wire, and it looks like he was using a forklift battery connector - those are rated for a maximum of about 350 amps, with very large and low voltage drop terminals inside it.
It is 'bad' on a engine to sit idle. There is not enough oil flow to the heads, and the pushrods will not get enough lubrication. At over 1,000 RPM, then the engine will see many quarts of oil going to the heads, and pushrods will lube fine. Also carbon will build up in a diesel engine. 10 - 15 minutes will not be to bad, but still if you get a flat cam, it is normally due to someone who sits in the truck with the engine idling to keep the A/C on while they do paperwork, or on a van with a lift attached to it, that is left running to run the crane lift hydraulic motor.
Good luck with your system.
Fred. - landyacht318ExplorerIdling to recharge is wasteful.
But, If one employs thick copper between distant battery and alternator, 50 to 80% can be achieved fairly quickly, IF the alternator can output 60+ amps at Idle without damage from overheating, and If the voltage regulator is seeking mid 14's instead of 13.6v. 80% to 100% takes hours no matter what.
Lots of 'If's' up there.
Use a 500 amp winch connector and 2awg cable, disconnect when camping, no Diode/isolator/solenoid required:
http://www.amazon.com/Superwinch-2236-commercial-terminals-capacity/dp/B000C7LYYM/ref=pd_sbs_263_2?ie=UTF8&refRID=1J8H2NJ0BYB8BASQRABX
I was able to get 100+ amps at idle into a single group31 50% depleted lifeline AGM battery through 2awg cable, that 500 amp winch connector and about 25 feet total circuit length from alternator to Lifeline's posts.
The '160 amp' alternator quickly heated to 220F and output then maxed out at 86 amps while voltage was still in the mid 13's, indicating the battery could have accepted higher amps. - AlmotExplorer IIIAre we talking about trailer battery? If so, - the wire in 7-pin plug from tow vehicle can support 10A only, as I recall.
At that rate, 2*T105 will need 7 hours to bring them from 50% to 80%. Running a truck any longer won't be too smart because the battery acceptance rate drops as it's nearing 100%. So, after you've spent all day to bring it to 80%, you'll have to idle for another day to bring it to 100%, because the charging process slows down.
Solar is perfect for those last 15-20%. If your energy needs are modest, 300W solar on the roof will keep it fully charged on most days, without ever running a generator or truck. As long as there isn't much rain or shade. - boogie_4wheelExplorerUsually, the tow vehicle will already be charging the trailer battery(s) when connected via the 7 (or 6 pole) plug. YOUR vehicle will determine if the tow vehicle 12V supply is powered while the ignition is in the off position.
Tow vehicle trailer plugs are usually fused or have a circuit breaker at 30A.
I have left my truck plugged in for awhile before bedtime to assist the trailer battery during colder camping while running the propane heater. I've also hooked a car to the trailer using jumper cables and left the car idling overnight to keep the furnace running when power was lost in the trailer park (and it was -20*F). - FlatfiveNomadOkay. Got it. That's what I thought. We have switched to LED lights. We'll probably get a portable solar set-up soon. What is WyoTraveler talking about: " a diode and 10 ft of wire"?
- In a pinch fine but I would not have idling as my primary charging source.
200 watts of solar will go a long way. Don't ignore conservation with LED lighting. - old_guyExplorerat a lot of star parties in Oregon the forest service controls the use of generators. so many do charge their batteries by running the tow vehicles. no other way to do it on the years that genns are not allowed
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