Modifying The 36-Amp Megawatt List Of Materials

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Know before you go...

If moi can pull the circuit board with one good hand, then anything superior to a primate has an excellent chance to do it as well. I fully intend to cover the tight fit of the circuit board. It's merely a matter of wiggling it out. The 5 screws holding the board to the case bottom are wide open to view. Frustration is breaking the pull tab off on the final brewskie. Frustration is getting a car jack stowed just right. Doing the mods to a Mega would be a challenge for an Attention Disorder suffering lumberjack with fingers the size of my wrist. Also folks suffering from acute DT's might find the soldering a bit of a speed bump.

Perhaps presenting a good better best approach for differing skill/ comfort levels.

For example,
Pulling the circuit board from the casing might be a deal breaker for some, and a one time setting unloaded voltage on original trimpot to ~ 15v, then adding the intermatic timer on the AC side, would be more than adequate for some.

A really good how-to guide, makes the user very comfortable all along the way.

Do yourself a HUGE favor.

Buy a 15-30 watt pencil tip soldering iron NOW, not later. Radio Shack solder is good enough. Let's get you soldering correctly right away. As a matter of fact an entire thread devoted to soldering and soldering tips is more than called-for. I think it was SCV Jeff, that embarrassed me into remembering that fine strand wire works as good as any de-soldering braid. I cannot express enough gratitude for his polite cheek reddening tip. It, of course, worked superbly. Thank you señor.

Count me in. But pictures, lots of pictures

Hmmm I do have a volunteer here ready with a Meanwell fixer-upper photo guide.

The Mega drops to 11.2 volts and tops at 15.83

Remember the DC to DC DROK booster connected through a 50 watt 12 volt bulb for 110 amp hour equalizing or through a 100 watt bulb for 6 cell golf car equalizing. The amperage throttling through the light bulb is crucial.

I like having to spin the 10 turn pot to change voltage. It means I can have sloppy fingers and worry about twitchy adjusters.

Only military grade pots are made so a user can play Wheel Of Fortune on the dial. Usually a person has an interest in doing a specific job like top charging. Filling in the blank area smart chargers fail to charge.

A battery that could be filled in say 2 hours at 14.8 volts yawns at an extra hour at 14.8 so exact timing is not life-or-death. Hominid erectus should have the capability of getting a feel for how much is enough. The rate of bubbles tells the story. Unless a person is the type who fell 52,000 times before learni g how to ride a bicycle getting the feel for a dial Mega is a snap. This ain't no stinking regular battery charger! Regular manual chargers do not have a voltage limiter. The dial Mega does. Dial a volt and dial the time makes a programmed in Calcutta Smart Charger look ludicrous. Remember Charger and Converter have different letters within.

Mex, what is the lowest voltage a MegaWatt will goto with a 500 OHM potentiometer?

I get that these will mostly be in thee 14.5v range where the losing some bottom end does will not matter, but I'd personally hate to not be able to go as low as the low 13's.

When I replaced the 1K ohm pot( measured at 973 ohms) with a 10 turn pot(1024 ohms) On my Meanwell, my minimum voltage dropped from 13.23 to 13.12v. More resistance = lower voltage, Zero resistance = max voltage.

I think I would lose the lower end of My MeanWell voltage range with a 500 ohm pot, making it useless floating flooded batteries, perhaps even too high for my AGM.

I feel the 10 turns pot 1K ohm is precise enough I can dial in voltage to 0.01v easily enough, and The Meanwell rsp-500-15 has a 6+ volt range of adjustment with a 1K ohm pot.

What is the max voltage of the Megawatt? Trojan now specs 16.2v equalization voltage.

Perhaps those wanting more than 15.5v for flooded battery Equalization, might want a Meanwell rsp-500-15. 40 amps, power factor corrected, and a 13.12 to 19.23 voltage range, but also twice the price of the Megawatt.

The only thing clubby about this is a wish to have a freakin' battery charger that does what the name implies. I will say this: A decent pencil type solder iron is needed. Radio Shack solder will do fine and that third hand gizmo (really cheap at Harbor Freight online) is almost essential.

Dig up a short length of twin lead tiny wire somewhere. Off a computer muffin fan or junk plug-in wall adapter. This will be the connection between the tabs on the existing potentiometer and the new one. Also you need something to glop onto these wires where they're soldered onto the pot's tabs. Don't want them breaking off after an "oops, clumsy me".

I am going to do the 4-hour Intermatic timer thing. Your decision yes or no. For battery charging having the Mega shut off means faster way faster charging when using a generator for power. The Intermatics do not have a "hold" setting but they do click off by timer or by twisting the dial.

A big recommendation is to start ordering this stuff right away. The heat sink compound will take nearly a month to arrive from China. Same for the 10 turn pot.

And don't sweat getting Shanghai'ed into a project you can't handle. When I wrote instructions I got kudos. I know what confusion and unclear E=MC2 means. None of that here. The most technical things will get is finding 2 of the three terminals you need on the new pot. 0-500 ohms range. Big deal. The meter will also help you set the new pot and the you'll lock it with it's thumb lever.

And yeah when you're done you'll have a 36 amp charger that a wimpy 500 watt Honda won't gag on. Dial the voltage setting back until the generator stays running then every half hour or so bump it up until the generator starts loading down. Yeah I'd -love- to see a smart battery charger do THAT.

I want to know what became Megawatt so I'll be here.