Converter vs Battery charger

rjxj wrote:

MEXICOWANDERER wrote:
If I had to put up with push button this and do that or something other four times and then watch for a blinking light...I'd put a couple of rounds in it.

I agree. That's why I like the Quick Charge. Flip the switch on and forget it. But now that I'm getting a Mega watt what will I need to do? I have 10 gauge wire run to the batteries. About four feet total.
Do you start out with the mega watt at 15v? What do you suggest?

I missed this entirely. Sorry.

It's a power supply so start it on a tabletop and tweak the trim pot back to 14.0. Connect to batteries, restart and see if the battery ends up at 14.0.

Playing teeter-totter charging while dry camping on a generator, the object is to safely replace as many amp hours as you can in the minimum amount of generator run time. I like 14.8 volts for this if the temperature isn't higher than 80F.

Go online, go to Amazon.com and search for INTERMATIC 6 HOUR or INTERMATIC 12 HOUR TIMER. A four hour timer is actually enough. Who cares as long as it's not a 1 hour and you have to wind it back up. A pain to have to remember.

The Intermatic fits into a duplex receptacle box. At Home Despot I choose the plastic one for obvious reasons. The Intermatic is a snap to connect (utterly basic wire pigtails to butt to) and fourth grade level hookup directions.

Now you have both amplitude (voltage set trimmer pot), and time command at your disposal. The timer is spring wound powered not motorized. A tough as nails customer.

2 Golf car batteries, somewhere around 50% state of charge. 110 amp hours to feed. MW has 33 mp capacity. A 55 amp smart charger is on board so you wisely let it run as long as it can before going insane and running away to join the circus. Then the MW is employed at 14.8 volts. Twist the timer and watch the volt meter in your rig. If it rapidly sproings to 14.8 volts you are within the 33 amp charge voltage limit range "WE HAVE ABSORBSION!" Keep a note of how much time you dialed in on the Intermatic it is important.

Take a peek at a couple of easy to get to battery cells. If they are bubbling vigorously at 14.8 the proscribed end of needed charging is near. With a Norman Bates converter, good luck with seeing vigorously bubbling cells right away. The cell has to bubble around 2-3 bubbles a second for this to be meaningful. Cells are now bubbling as per spec. OK how much time did it eat? The intermatic keeps good track of this while it is winding down.

GENERALLY speaking if there are no loads sucking power the battery voltage will ramp down to maybe 13.2 and then hit mud. From then on it'll decline slower and slower. You don't have time to watch it settle at 12.75 so grab a hydrometer this one time. Lets to have a look at the weak sister cell in the bank. First to fall last to rise.

Whewee, 1.280 temp corrected. Go pop a brewskie.

Next time around, dial the timer for a half hour less. See if that does the trick. This is a fast learning track.

Having an amp hour meter really simplifies this for the most obvious of reasons. The way I described it is hammer and chisel.

The MW fills in the missing upper 15% of the battery state of charge that SMART chargers are specifically designed to ignore on generator power.

"Hmmm, the smart charger goes offline, I dial in an hour and forty minutes at 14.8 with the MW and the batteries get charged. Pretty simple to remember."

Meanwhile back at the farm

Tweak time. Set the pot for 15.0 volts. Top charging. Once a month go out and twist the dial on the Intermatic for 30 minutes to an hour. I'd do the peeping Tom bit on weak sister the first couple of tries.

Equalize! Get those 12 volt light bulbs connected in parallel if for more than one battery. This is gonna take a couple of hours at least at 15.5 volts. Return occasionally and spy on the voltmeter. The light bulb restricts charging amperage hence voltage is going to rise slowly. With 4 golf car batteries equalization at 5 amps can take 10 hours. Get the point with the 12 hour timer model, now? Badly sulfated GC's can take 15 hours or more to equalize. 2 twists of the dial. Can;t have everything...

Trends and tendencies. The hydrometer is truth serum. Having instrumentation really helps as well.

The voltage adjustment pot

The timer

Volt and amp gauges

Truth serum verifier hydrometer for setup

Your brain

Compared to the best of SMART CHARGERS

It's like comparing the intelligence of Stephen Hawking to an iguana

Trends and tendencies. Voltage, time. It's so easy to learn and so thorough. Hmm, 12.18 volts this morning. Run converter for two and a half hours then the MW for an hour an 45 minutes. Actually I just described a case where a bigger converter would pay off.

Don't bother trying to run both the MW and your SMART CHARGER at the same time. Your smart charger will lean on a shovel and watch the MW work.

The object is to get those batteries to 14.8 (yesyesyeyes adjust for temperature) as fast a possible, My monster system goes to 29.6 volts instantaneously with 388 amperes input.

I am building my Ammo Box charger to use a pair of 40 amp MW power supplies. Yes it has an Intermatic and full compliment of instrumentation. Gotta rule in my lifestyle: When the generator starts, it goes to work. It is not a shovel leaner...