Charging Battery More Efficiently

Power supply amps output is "burden"
Think outside honorable box...

pnichols wrote:

NinerBikes wrote:
Your EX650 does not have an inverter. It has to maintain 3600 rpms to provide 60 cycles per second input. So what you are proposing is a bad idea with the generator you own. You can not drop the rpm's on it, under load.

Note that I said "burdened" ... not "slower". The EX650 gets louder under load, not slower. I would listen for a slightly louder sound from the little genny while turning the knob.

The EX650 will not slow up - it's circuit breaker will open when current load becomes too high. I guess instead of listening, I could use an AC watt-meter and stop the power supplly knob turning when the input to the power supply reached around 500 or so watts from the Honda .... or turn the knob until the circuit breaker opened ... several times to get an average. I'd then use a power supply output voltage knob setting a little less than the generator's "circuit breaker open" point.

well then, give it a try, and get back to us with a report with something new to add to the knowledge base.

NinerBikes wrote:
Your EX650 does not have an inverter. It has to maintain 3600 rpms to provide 60 cycles per second input. So what you are proposing is a bad idea with the generator you own. You can not drop the rpm's on it, under load.

Note that I said "burdened" ... not "slower". The EX650 gets louder under load, not slower. I would listen for a slightly louder sound from the little genny while turning the knob.

The EX650 will not slow up - it's circuit breaker will open when current load becomes too high. I guess instead of listening, I could use an AC watt-meter and stop the power supplly knob turning when the input to the power supply reached around 500 or so watts from the Honda .... or turn the knob until the circuit breaker opened ... several times to get an average. I'd then use a power supply output voltage knob setting a little less than the generator's "circuit breaker open" point.

pnichols wrote:

MrWizard wrote:
considering their "intended" use.. most likley was too be set once, and left alone
Not tinkered with and adjusted all the time

If I had one, I'd adjust it only once - but want to do it using a big ol' knob with graduations on it.

I'd adjust it with my coach battery bank reading around 12.0 volts at rest. Then I'd fire up the 650 watt Honda, plug the power supply into the Honda, then attach the power supply with big ol' wire to the battery bank with the voltage knob set to about 1/4 of maximum. Then I'd begin turning the knob in the higher voltage direction until the Honda just sounded burdened.

I'd leave the knob permanently at that setting for those particular batteries and that particular generator.

You can use that kind of burden technique on a motor that has an inverter and will give a full 60 cycles per second, regardless of engine rpm.

Your EX650 does not have an inverter. It has to maintain 3600 rpms to provide 60 cycles per second input. So what you are proposing is a bad idea with the generator you own. You can not drop the rpm's on it, under load.

MrWizard wrote:
considering their "intended" use.. most likley was too be set once, and left alone
Not tinkered with and adjusted all the time

If I had one, I'd adjust it only once - but want to do it using a big ol' knob with graduations on it.

I'd adjust it with my coach battery bank reading around 12.0 volts at rest. Then I'd fire up the 650 watt Honda, plug the power supply into the Honda, then attach the power supply with big ol' wire to the battery bank with the voltage knob set to about 1/4 of maximum. Then I'd begin turning the knob in the higher voltage direction until the Honda just sounded burdened.

I'd leave the knob permanently at that setting for those particular batteries and that particular generator.

I tried a three-quarter turn pot and it was just too touchy. I think a quality three turn pot would be about right for me but finding a good 500- ohm 3-turn pot gave me a headache.

Look folks. The Mega or the Meanwell fixed at 14.8 volts makes a HECK of a good generator charger. Naio, find an electrical shut-off timer at the hardware store that woulb be easy to set at 1- hour or three hours. It would then shut the charger off automatically.

You're in camp. You want to use the charger because your battery meter says 12.1 volts. Look at a clock. Pry off a battery cap and set aside. Start the generaror/ charger. A hour later with a flashlight go look down into the uncovered battery cells. Is the liquid bubbling? If yes, the battery is charged. Note the tine - of course one hour. If the battery needs two hours to start bybbling so be it. However long it takes the NEXT battery charge will take as long so set the timer for as long as it took. When a battery starts bubbling at 14.8 volts it is charged. Get a friend or neighbor to help you with connecting the power wires to the charger. Hardware stores sell 3-wire extension cords that will work perfect when the end not needed is cut off.

Go to a Big Lots store and buy a cheap pair of jumper cables. the jumper cable label will have a size for the cables make sure the size which is a number is not less than number 10. number 8 is too large use only number 10 jumper cables. on one end of the cables cut off the clamps and use that end of the jumple jumper cable pair to connect to the charger.

Clamp the jumper cables to the battery post
Plug in the charger to the timer and the timer to the generator.
Start the generator. Set the timer for TWO hours.

Go have a beer. Your checking of the battery will be an hour away. And every hour thereafter.

Once you know how long it takes your battery to charge back up then your watch or clock plus the timer makes this a snap.

I love having the opportunity here to read the differing opinions of knowledgeable, intelligent people!

Someday maybe I will know enough to decide who I agree with :). Right now sometimes I worry that whatever I do in my own rig, I will be offending someone I respect. This is giving me a bit of analysis paralysis.

Naio wrote:

So nobody makes an adjustable one that is meant to be adjusted all the time? In my dreams it would also have a timer, also easy to set.

Powermax makes adjustable voltage power supplies in various amp ratings, but there have been some hiccups regarding implementation that were detailed in the closed thread a page or 2 back.

The Meanwell I bought was never intended as a battery charger, and the adjustable voltage pot was not designed for continuous and simple adjustments. They are a power supply, designed to be set once and closed up within the device needing a certain DC voltage

The Adjustable voltage power supply used as a battery charger is for the over controlling type who does not trust a plug and play automatic charging source to the the job it claims to do, and to reduce generator run times, by forcing a high absorption voltage to be held as long as desired.

They are also not designed to be at max output for their whole time in use, which is what a depleted battery will do.. Increasing cooling when maxing them out is wise.

I too would not mind having mine on a timer, but so far have not bothered implementing one on the 120Vac side.

MeanWell also makes 24v power supplies of various amp ratings.

Some solar controllers do allow voltage charging parameters to be set, but do not allow one to directly limit amps.

pnichols wrote:

landyacht318 wrote:
The meanwell/megawatts have very small voltage adjustment dials requiring insertion of a jewelers screwdriver and a fine touch,

That's an inexcusable design flub right there. A 10-turn pot is not necessary ... a 3/4-turn one is OK ... with a large knob and a scale around the perimeter.

No, it's an inexcusable operator flub, when the person fiddles with the setting constantly, knowing it is originally designed as a power supply unit, but is being employed outside it's original design scope when being used as a charge controller instead, and as a bulk charging single stage charger, at that, strictly for bulk charging while dry camping, to get your flooded lead acid batteries to a 90% SOC, as quickly and as efficiently as a hard working generator burning expensive gasoline will allow. It's an operating parameter limitation, by design.

I would suggest in your case sticking with your free Honda EX650 and a 3 stage charger, if you are worried about the pot on a meanwell or a Mega Watt being inadequate, especially if after all these years, you don't comprehend what Mexicowanderer has been posting for over a year now about using PSU's as a dry camping single stage, bulk charging device only. Modify at your own peril, as landyacht has done, but he knows exactly what he is doing in these areas in attempting to recharge batteries.

mitch5252 wrote:
I have a single Group 27 battery. I love to dry camp. I have a Honda eu1000i generator and a wfco (?) 55 power center.

which is the most efficient way to charge the battery - connect the battery directly to the battery or plug the trailer into the generator, or neither is better - they would both charge at the same rate?

Thanks.

You have a single group 27 Deep cycle rated at what 85 to 90 Amp hours. Half of that is 45 amps, that is useable. You'd be better off with a group 27 not getting it discharged much below 60% SOC. .4 x 90 amps would be 36 amps used. You'll get to 90% SOC with some efficiency with your Eu1000i, so replacing .3 x 90 should be your goal if weekending it, with a full top off recharge to 15V or more when you get back from camping.

So you are looking at replacing 27 amps, maybe 36 if you did a 50% SOC discharge cycle.

What I would do is buy the MegaWatt 30 amp model, it already comes with a cord and an on off switch, set the voltage on it at 14.8 or just a hair above that, 14.9V, with it fully disconnected from the battery, make a set of charging cables, and install an inline RC watt meter to the charging cables. Run the Honda until you are at a 7 or 8 amp rate of charge take rate to the battery, and then shut the generator off. Do this while camping.




Plug in your WFCO when you get home to the trailer, and let that run for 3 days at 13.8V to top charge the battery, then disconnect the battery for full time storage, and also disconnect the trailer and it's electrical to the WFCO. You should be fine.

Every camper should own a digital multi meter and a hand held amp meter, as well as a good high industrial grade hydrometer for battery maintenance purposes.

When your group 27 dies,strongly consider replacing it with a pair of GC-2 6 volt golf cart batteries wired in series, if you do much dry camping off the grid, which it sounds like you do, if you already have the Honda EU1000i.