20 Amp 15-Volt Meanwell For Smaller Generators

That's what nice about the "micrometer" dial-in knobs I fitted to the Vishay pots. AGM batterues DEMAND to be charged at LOW bulk voltage set point until amperage decreases to ?1% of total amperr hour capacity before deflectimg to float. How ya gonna do that with a smart charger? In your dreams. If by some miracle I am alive to see the end of my Lifeline I would be 83. Treating any battery correctly leads to a phenomenal lifespan. I had 29 plate 8-D's that survived 1000 cycles before I gave up. Flooded Ramcar Philippine batteries. But that happened a quarter century ago.
You can PENDANT until you faint but any charging system that does not allow adjustable length of time spent at max voltage absorbsion limit is not acceptable. A huge flaw. In the case of AGM batteries it's that less than one percent goal. With flooded reaching 95% of full charge gravity is the goal as the lag over run chemical reaction will continue to raise SG

John,

My batteries only need two stages: Their specifications say to float at 13.6 volts to 13.8 volts, and charge at 14.5 volts to 14.9 volts.

I shopped specifically for batteries like this so that I could continue to use the stock RV converter for safely floating them, and also use the alternator for fast charging between campsites. Since they're AGM with very low internal resistance, they also most of the time charge fast enough for us when camping using the 13.6 volts of the converter.

A single voltae out unit like that is not really good for battery charging

you really need a 3-stage

I remember desoldering the pot and adding 22 awg wires for a remotely mounted 10 turn on the Cheapowatt to be pretty easy. Hardest part was getting the thermal grease off my fingers from the disassembly of heat sinks from casing.

Much more difficult and involved on the Meanwell with a much higher price for failure. I cursed up quite the storm getting the old pot out, and the holes for the wire insertion cleared. Much less room to work and a double sided circuit board to deal with.

Gave me confidence though. My soldering skills have improved since, just keep the bernzomatic electronics lead free solder away from my iron or gun.

A person dpes not need a small power supply with a small generator. Period. But all of the power supplies have fragile hypersensitive trimmer pots that defy easy use. Why they do not fit a 69 cent 10-turn cermet I do not know. But disassembling the power supply to solder in an alternative is not for everyone. Me included. But it has to be done. I purchased caliper dials to fit the 500 ohm Vishay pots so I can dial-in a voltage by numbers. The Borg has a pair. My latest quest is 4-1/2 digit voltmeter and ammeter with 1.1" LED segments. Lools like the 5-amp float will be 13.2 volts fixed.

The 90-amps potential is enough to satisfy any portable responsibility.

Landy sure found out about parchment thin starter battery plates and thermal gain.

With caliper dial and chart the power supplies become very user friendly. Yes mine has an Intermatic 7-hour spring wound timer. I can play this thing any way I want up to 6-hours then the float kicks in. The float is plenty to sustain my BiPAP.

Now I need someone who does electronic repairs to solder in the pots.

I just installed a couple of 115 AH AGM deep cycle coach batteries so don't know how they're going to act with our stock 13.6 volt converter under various charging start points.

The two 100 AH AGMs they replaced NEVER would draw anywhere near the full 45 amps available from the stock 13.6 volt converter, so I knew that 13.6 volts was not enough to make those AGMs guzzle high currents from a 12.2 volt SOC starting point. I'm expecting about the same behaviour from the new AGMs.

However, under the higher charging voltages from the alternator, the previous AGMs would begin to drink up the current.

The above scenarios full right in line with what everyone talks about - and the engineering graphs show - regarding how just a bit higher charging voltages can cause lead acid batteries to accept way more charging current .... hence charger faster with higher initial charging voltages.

The above realities of battery charging lead me to believe that by playing with any Megawatt's output voltage adjustment, one can tune it so as to get the best charging speed possible with about any size battery bank with just about any size generator available. Of course, the smaller the generator, the longer the charging time ... you can't tune your way out of that.

Your new AGMs depleted to 12.2 resting, will still suck everything the power supply can make, if you cannot lower the output voltage of the power supply to very close to that 12.2, then dial it up slowly until the generator starts struggling.

My Meanwell goes down only to 13.12v, not sure about the MegaWatt.

Either of my group 27 or 31 batteries will take 40 amps, but briefly, when the PS is first hooked up in the 85 to 90% charged range, even when set at 13.12v.
My watt meter records peak amps and minimum voltage.

Mex, why does one need a small adjustable output power supply to go with a small generator?

For example, why can't a 60 amp Meanwell be used with a Honda 1000i (or even with my Honda EX650) by merely turning the Meanwell's output down to some low enough value - like 14.1 volts - so that the little genny continues to hum along supplying whatever the batteries will accept with only 14.1 volts on their terminals? Just "tune" the power supplies output such that it just begins to load down the small generator but not kill it.

Doing this, one can buy a large Meanwell ... so as to be ready for charging when on hookups or charging whenever a larger generator is available ... but also use it with a small generator.

Aha! Explained.
Now I have to install a pair of caliper adjustment 10 turn pots on my Megas. Shaky, weak hands with crippled left hand. Ooooooo this going to be honorable butt-scratcher or fling power supply through window odyssey in frustration. I hate being old. It's a quad-core I7 brain coupled to a 286 operating system.

You are absolutely correct about the auto foldback feature making the 20-amp Meanwell virtally useless for battery charging. Well it's back to a Megawatt and starting out at 13.2 volts to keep the generator from hara-kiri. Thanks for correcting me.

Sorry Naio, did not mean to confuse. This was just a different observation of battery charging compared to what I have observed a hundred or more times now with my adjustable voltage Meanwell and its attached watt/volt/amp meter/counter.

I had the Meanwell set to 14.45v when I plugged it into the over depleted starting battery which had measured 9.23v on my multimeter when the owner dropped it off to me.

I am used to seeing a 50% depleted battery just slowly climb toward 14.X at a solid 40 amps until battery voltage approached the my desired 14.x set voltage of the meanwell, and then amps would taper.

This over discharged 3 year old starting battery instantly rose to 14.45V and it only required 23 amps to get there. But after 30 seconds to a minute of slapping this battery upside its head, the voltage had dropped as the battery decided to stop resisting the meanwell's full available current. It was like removing all the hair and junk obscuring the drain on a sink.

I had heard about this behavior on an over discharged battery, I had just never witnessed it, and it was neat having the tools to watch it occur in real time.

I did notice the battery getting hot at 40 amps, and I wound up dialing the MW voltage all the way down( 13.12v) in an attempt to lessen the amperage. It worked, and the rapidly climbing battery temperature levelled off and began to drop, with a fan on it. I just came back every 15 to 20 minutes and kept bumping up the voltage little by little trying to keep it under 25 amps. Soon it was at 14.45v and I just held that Constant voltage, Absorption stage, for about 6 hours, unmonitored as Friday night occurred. It was only taking 1.23 amps after those 6 hours at 14.45v.



And I will stand by my opinion that one desires constant current limiting on overload, rather than automatic shut down until overload is removed, or hiccup mode on current overload.

But if one is only starting this Meanwell after another charging source has gotten the battery to absorption voltage for a while, then that works too.

I personally wanted an All in one charger, equalizer, and float voltage converter. I got sick of weighing the compromises when comparing/researching other charging sources. I love the MeanWell's freakish ability to bend any LA battery to my will. It cost me 127$ delivered, but I put another ~30$ into it with quieter additional fans, and 1K ohm 10 turn potentiometer, and solder and the Wattmeter inline on 8awg with 45 amp powerpole, was another 25$ or so.

----Distant maniacial laughter fading-----

Thanks Mex, for turning me onto the possibility of a Powersupply as an adjustable voltage, Kick burro manual charger.