bonvanroulez said:
But in searching I've read Sternwake say it will do 45 amps at 14.8 volts, getting up toward 700 watts? That's getting close to the Sportsman's 800 watts.
My wattmeter will hit just over 600 watts total output, and in general the max amperage is 40 amps at ANY chosen voltage between 13.12 and 19.23v, not 45amps.
My wattmeter on my Meanwell output will pretty much max out at 40.97 amps at any voltage, and my DC clampmeter, before the most recent set of AAA lithium duracell batteries, stopped at 40 amp almost on the dot. The new AAA's claim the Meanwell is doing 43.5 though the wattmeter still says 40.97amps. I am disappointed that the Clampmeter's readings changed so drastically with the AAA lithium batteries, and this could be due to their slightly higher voltage and perhaps retaining much more voltage under the load the clampmeter presents to them. A guess. i know not. I could test with regular AAA's, but .....
When I first got it I tried to use NiMh AAA's and accuracy was pitiful on voltage and amperage.
I have not put my clampmeter over the AC wiring to see just how much AC input it requires. I should borrow my friends Kill a watt for some data on that, but he can't find it and I'm too cheap to get my own.
The thing with these adjustable voltage power supplies, is that they are manual chargers, requiring human input and observation and control.
IF the powersupply can stall the generator when set to 14.8v and hooked to a depleted battery, well the likely solution is starting the powersupply at a much lower voltage, and raising the voltage until the generator struggles. One can control amperage by the voltage. The rsp-500-15 minimum with the stock pot (973 ohm) was 13.23 volts. My bourns 10 turn pot OHmed out at 1027 and minimum voltage dropped to 13.12. It is possible 13.23 or .12 could still overpower the generator on initial hook up to a depleted battery. Only way to know is to try it.
The 36 amp Megawatt voltage can be turned lower than 13.12 thus lowering the voltage delta and thus the amp flow when first hooked to a depleted battery.
http://www.12voltpowersupplies.us/
But the voltage dial which comes with the meanwell/megawatt requires a jeweler's screwdriver and a steady hand to adjust precisely, and is not rated for many cycles, 25 to 50. it will not take kindly to repeated and often voltage changes and when worn might have voltage kind of YOYO in a certain range or just not be controllable at all depending on how it wears.
A powersupply without the modified voltage potentiometer should really be set once to 14.8v, or similar, and adjusted as little as possible for fear of wearing out the provided mini potentiometer.
Modification of the potentiometer required me to disassemble the meanwell, lifting the circuit board from the casing, which is used as a heatsink. The transistors are bolted to the casing, and have a thermal pad and grease to help transfer heat, but also keep the transistors electrically isolated from the casing.
It is easy to disassemble, and soldering in the wires is not all that hard, but it was stressful as I was pretty new to soldering on circuit boards and soldering in general.
Perhaps the stock pot legs could be snipped without disassembly and wires soldered to a better potentiometer, but access is limited and I feel more soldering skill would be required to pull this off, as well as some nippers which could get in there and cut the pot legs close to the underside of the pot, leaving enough of the leg to solder wires to.
This should not be difficult for an experienced electronics repair tech. I most certainly did not and do not qualify, but I pulled it off, and could do it faster and cleaner today haveing had a lot more experience since september of 2014 when i did pull it off.
The MEanwell is PFC, powerfactor corrected, meaning it uses less ACwattage to make the DC output wattage, The Megawatt is not, so if one is at the limit of a generator, a PFC charger should support higher output amps into battery before stalling the generator.
Really this is a lot of supposition and theory, and the proof is in the pudding by someone actually doing it, not someone who has just read about it or 'thinks' it should work according to what they think they know.
I have never run a charger from a generator, and thus have no experience in this specific matter, so do not take my suppositions and theories as fact, please.
More data is required, and that requires actual testing by someone with the knowledge and measurement tools and experience, and common sense, and the Desire, to do so.
