Battery chargers

[sawguy21]

Yesterday, I had a customer looking for a 12VDC 100 amp gas drive generator. He looked at a 110W a/c portable trying to figure out how to rewire it. Then he told me he wanted to charge his 100 amp hour trolling motor battery in one hour instead of ten hours with a ten amp charger ??? I gave him a brochure and wriggled out.
He determined he needed 2.4 hp to produce the power so next thing I knew, he had the partsman pinned looking for a brushcutter or chainsaw engine to drive a truck generator. I hope nobody else is in the neighborhood when he fires that contraption. :D

[Tom]

That has been common here for years.  Dyed-in-the-wool fisherman who camp on the reservoir build a little generator that they roll around on a hand cart to charge their trolling  motor batteries when they come back to camp.  It's an Auto alternator/generator that is driven by a little 3 horse Clinton or Tecumseh.  It's actually a pretty good idea if you find yourself away from facilities.  I wouldn't mind having one myself. ;D :D

[sawguy21]

Fine Tom, that is common here too but don't throw a hunnert amps at it. The least of his problems will be a battery boiled dry and buckled plates. That thing could grenade.

[rebocardo]

I have used portable generators that can easily put out 100-400 amps to charge semi tractors. The trucks usually have 4-8 large 650 CCA batteries. The question is how long the battery is going to last and how much of a chance you want to take on an explosion. You fast charge a battery and bits start flaking off and settling to the bottom from the plates, which means less of a charge and more chance on a cell shorting out.

Myself, I would usually remove the batteries and slow charge them while I put a fresh set into the truck.
Because I know fast charging destroys batteries.

The real solution is a second battery called $110 Red Top or $150 Yellow Top Optima from Advance Auto Parts to use while you slow charge the other trolling battery.

The worse part about rapid charging batteries is the battery is most likely to fail quickly under load, usually in the middle of a lake or ocean  :D

> I had a customer looking for a 12VDC 100 amp gas drive generator

If he insists, Handy Industries

http://www.handyindustries.com/

makes them and will be 100% content to sell him something to destroy his batteries. You can also buy portable gas generators from northern toolhttps://forestryforum.com/board/index.php?action=position"> Note:Please read the Forestry Forum's postion on this company that start at $500. The portable Hondas with the 12V output start about $700 and will run about 5 hours on one gallon of gas.

[Ianab]

Hopefully he will be hooking it up with a proper automotive regulator that will limit the charge voltage to the normal 13.8v. Then the actual current into the battery will be something reasonable (determined by the battery itself) Of course it may only be 30 or 40 amps not the 100 he wants.  :
But if's he's hopped up the voltage to force more current in.. then yes a melted battery is probably the best scenario 

2 batteries does sound easier doesn't it?

Ian