48V Battery Charging w/GM-90-16/1 & MARS Motor

[Incredilion]

I did it!
 I FINALLY got my 16/1 done, and connected to a MARS (Etek) Motor, to use as a generator AND starter for my big old 16/1.

Here's the story;
I have a good sized house (3000SF+) that I took off the grid last summer. Have 1105 AH Forklift battery.
I have a Magnum Inverter/Charger that puts out about 60 Amps charging current, which isn't enough for the battery to charge efficiently.
So; I got a MARS Motor, this is a motor used in electric driven vehicles, golf carts, motorcycles, etc.
Long story made short:
This motor driven at about 2800-3000 RPM produces about 120 Amps @ 48-55VDC, so it charges my batteries MUCH better than the 60 amos from the 12KW generaotr head/Magnum Inverter's charger.
ALSO.....
I connected it to a 12V car battery, installed a solenoid & switch, and the same generator that gives me power (LOTS O POWER) also starts the 16/1 for me!!! (BONUS).

Anyways, the motor/generator cost about $485.000, I had to install a 150A fuse & a set of diodes to syop power from backfeeding from the battery, so altogether I'm around $550.00, not including the little mount I welded together for it, and the alternator bracket that cost $7.00.

This works really good, hope it helps any of you who need to charge large batterys.
Chris
 

[LowGear]

Overcharging?  Or is this a myth?

50 Amps @ 50 Volts = 2.5 KW  Does anything get warm?

Casey

[Incredilion]

Casey, forklift batteries like to be charged (are most efficiently charged) at a minimum of 10% of their rated capacity. So; for my battery, it's an 1105AH battery, so it needs 110 Amps to charge it efficiently.
As to getting warm, no, the cables feeding it the 110+ amps are #1 welding cable, about 20 feet long, and I'm putting a lot more than 2.%KW into them from the generaotr alone, more like 6KW, or 6,000 watts, at the same time, my solar will input up to 117 Amps if the sun's out full. This mornng, as an example, I had about 35-45 amps coming from solar (cloudy day) at the same time I was charging with the MARS Motor. I was charging at about 135 amps, as the house was using about 10 amps. Battery got all the way up to 70 degrees.

Overcharging for my battery/s would be somehwere above 180 amps at whatever the voltage is on the batts.

[Jetpilot]

Got any pictures??

[Incredilion]

No pics yet; I'll be posting an article on my website later on it, soon as I have some time to write it. Without putting up a link to my website, the name of my company is my posting name, with "Realty" on the end, and I'm in Idaho.

[LowGear]

I learn so much stuff on this site - neat!  Is that 10% pretty much a rule of thumb for most lead-acid batteries?

Casey

[Incredilion]

Casey, I'm not sure about all lead acid batteries, but I do know that if you undercharge them current wise, it still works fine & doesn't damage them, it just takes a LOT more overall power to get to the state of a full charge.
Agree with you totally on how much a person can learn at a place like this, I've picked up tons of info here, and thankful for all of it.

Oh yeah, and my bad, I used the Incredilion one on this one, my comapny's name is Revolutionary. (Realty)

[mike90045]

Generally, most lead acid batteries like a charge between 5 - 15% of Capacity "C".  10% of C is easy to calculate in your head.

Below 5%, and you risk both stratification (where the bubbles don't stir the electrolyte around, and it layers out - acid at bottom, water at top) and sulfation, where a <5% charge takes too long to recharge, and the sulfur crystals start hardening up.

Too high of rate, they heat up, and unless your charger has temperature compensation, you get into thermal runaway and plate warp.

http://tinyurl.com/LMR-Solar
http://tinyurl.com/LMR-BigLug
http://tinyurl.com/LMR-NiFe