charging 48, 60, 72 volts

Nate · 02-07-2008, 11:46 PM

Buckmanmike, if you want to charge two 6V batteries in series you should have them close to each other as far as how discharged they are. For example: If your camera has an auto shut-off the two batteries would be in a very similar state of discharge. Then use the lowest amp setting, preferably around two amps to recharge.

Nate · 02-07-2008, 11:57 PM

Quote:

Originally Posted by killsumptin

Nate:

Now I'm curious. How did you convert the 12v charger with the 100a boost to 72v continuous

OK killsumptin it is not as difficult as it is going to sound. I have to use some technical terms to describe accurately though.

Schumacher used a transformer with two secondary windings each with center taps then charged using a full wave rectifier. The two secondary windings were isolated from each other so I was able to reconfigure. I put the two secondary windings in series then used a full wave "bridge" rectifier, which is double the voltage over center tapped full wave.

It sounds worse than it is; the fabrication was a heat sink for the bridge rectifier and fan.

scottyb · 02-08-2008, 12:30 AM

Dang, that was simple........Now where is that emoticom for ...
"right over all our heads?"

That, friend, is why you are the answer man....

killsumptin · 02-08-2008, 12:44 AM

So you effectively doubled the number of windings in the transformer by linking the 2 secondary windings in series?

Now "splain" me somethin', what is the difference in the full wave and the full wave bridge rectifier?

I guess I need to dig out my textbooks. You know how it is, if you don't use it, you loose it.

Nate · 02-08-2008, 12:58 AM

The primary to secondary ratio is the same; this determines your output voltage and amperage. Since the transformer had a 100A boost stage it had a higher output voltage on the secondary. They were run in parallel for the added amperage. (100A DC at 12V is only 10A on the AC side). Plus the full wave with center tap meant it was only half the voltage of the whole secondary winding.

Full wave means you use the whole AC wave. With a center tap you use two diodes on the top and bottom of the winding and use the center as a common. With a bridge you use four diodes and the whole secondary voltage and leave the center tap dis-connected.

I don't think I am explaining this very well, it still sounds complicated.

4vertical · 02-10-2008, 10:41 AM

sounds cool. no matter how you explain it, i think it will be way over my head!!

if i ever need one done i'll give YOU a call!! LOL

-Aaron

roady89 · 02-10-2008, 11:38 AM

Nate...Could you throw up a diagram and some part #'s. I'm pretty confident "I get it" but a simplified diagram would help.

Nate · 02-10-2008, 09:49 PM

One Schumacher automotive charger with 100A boost.
One Full wave bridge rectifier in the 20A range (I like overkill)
One heat sink and muffin fan.

I have pics but will have to shrink them so folks don't have to wait two hours for them to load.

buckmanmike · 02-12-2008, 05:00 PM

Back to my original question. I noticed the charger I was talking about is a manual model, so it is off my shopping list.

02-07-2008, 11:46 PM	#11
Nate Gone Wild Join Date: Dec 2006 Posts: 372	Re: charging 48, 60, 72 volts Buckmanmike, if you want to charge two 6V batteries in series you should have them close to each other as far as how discharged they are. For example: If your camera has an auto shut-off the two batteries would be in a very similar state of discharge. Then use the lowest amp setting, preferably around two amps to recharge.
Nate Gone Wild Join Date: Dec 2006 Posts: 372

02-08-2008, 12:30 AM	#13
scottyb lug nutz Join Date: Dec 2007 Location: So Cal Posts: 6,108	Re: charging 48, 60, 72 volts Dang, that was simple........Now where is that emoticom for ... "right over all our heads?" That, friend, is why you are the answer man....

02-08-2008, 12:44 AM	#14
killsumptin Getting Wild Join Date: Jan 2008 Location: Central Fla. Cocoa Posts: 111	Re: charging 48, 60, 72 volts So you effectively doubled the number of windings in the transformer by linking the 2 secondary windings in series? Now "splain" me somethin', what is the difference in the full wave and the full wave bridge rectifier? I guess I need to dig out my textbooks. You know how it is, if you don't use it, you loose it.

02-08-2008, 12:58 AM	#15
Nate Gone Wild Join Date: Dec 2006 Posts: 372	Re: charging 48, 60, 72 volts The primary to secondary ratio is the same; this determines your output voltage and amperage. Since the transformer had a 100A boost stage it had a higher output voltage on the secondary. They were run in parallel for the added amperage. (100A DC at 12V is only 10A on the AC side). Plus the full wave with center tap meant it was only half the voltage of the whole secondary winding. Full wave means you use the whole AC wave. With a center tap you use two diodes on the top and bottom of the winding and use the center as a common. With a bridge you use four diodes and the whole secondary voltage and leave the center tap dis-connected. I don't think I am explaining this very well, it still sounds complicated.
Nate Gone Wild Join Date: Dec 2006 Posts: 372

02-10-2008, 10:41 AM	#16
4vertical Gone Wild Join Date: Jan 2007 Location: La Porte Indiana Posts: 225	Re: charging 48, 60, 72 volts sounds cool. no matter how you explain it, i think it will be way over my head!! if i ever need one done i'll give YOU a call!! LOL -Aaron

02-10-2008, 11:38 AM	#17
roady89 Brkn it dwn BaRnEy StYlE Join Date: Jun 2007 Location: Kaufman, Texas Posts: 3,443	Re: charging 48, 60, 72 volts Nate...Could you throw up a diagram and some part #'s. I'm pretty confident "I get it" but a simplified diagram would help.
	Golf Carts \| Lifted Golf Carts \| Electric Golf Carts Custom EZGO \| B&S V-Twin \| All Sports Long Travel Lift \| 8:1 Gears \| 22" Titan AT489's \| \| \| \| \| \| \|

02-10-2008, 09:49 PM	#18
Nate Gone Wild Join Date: Dec 2006 Posts: 372	Re: charging 48, 60, 72 volts One Schumacher automotive charger with 100A boost. One Full wave bridge rectifier in the 20A range (I like overkill) One heat sink and muffin fan. I have pics but will have to shrink them so folks don't have to wait two hours for them to load.
Nate Gone Wild Join Date: Dec 2006 Posts: 372

02-12-2008, 05:00 PM	#19
buckmanmike Gone Wild Join Date: Oct 2007 Location: Snellville, Ga. Posts: 656	Re: charging 48, 60, 72 volts Back to my original question. I noticed the charger I was talking about is a manual model, so it is off my shopping list.

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