I wonder if it's possible to start a bike using a charger. By that I mean removing the battery completely, bolting the various wires that go to each terminal together [keeping each side separate of course] and plug them to the 'clips' of a charger. Would this start and run the engine ? I don't see why it wouldn't but am prepared to be educated...b.

 

is it possible, sure. is it plausible??? well maybe.

the issue i see is the charger itself. cheap chargers can use transformer or diode array and you will get a dc like current but with high ripple which can screw with electronics. on the more expensive or professional models, they filter the ripple and shunt the ac to ground make a very smooth dc current.

whoooooa!! you say, my motorcycle does not have a filter capacitor and the regulator changes ac from stator to dc so what's the diff??? simply this, the battery acts like a giant capacitor and filters the ac component out.
now will the machine run on the charger??? yep to a degree. when the battery is charged on the machine, it actually runs off the regulator and the battery only fills in the short fall. now if the charger can not sense the line voltage and adj current, then it over powers the regulator and it basically shuts off, so now the machine runs on an unregulated current.

so the answer is yes and no, soooo many choices and soooo little time???

 

i wouldn't do this ! you'll end up screwing up something on your bike like the regulator.

 

You'll need a high output charger - something that can supply around 50A, 60A, or 70A; whatever is needed to spin the starter motor on your bike.

There are jump starter modules available - search for "Antigravity Micro Start XP-10". These are a better tool than chargers for jumping a dead battery.

Hope this helps,
John

 

I would certainly be more likely to try that on an ancient bike that has no fuel injection or electronics than a newer model.

 

'Judge' that is exactly what I was going to try it on...an old Suzuki my son has had lying about for some years ! Don't want to shell out $100 plus on a model specific battery unless I know it was going to start the bike. Engine could be seized. Thanks guys I will keep you posted if I try it...b.

 

Make sure the battery has fluid in it if you can. Put it on a 2 amp charger for a couple hours and see if it maintains three of four volts for maybe 30 seconds after you shut the charger off. If it does, you can start the bike with a charger and use the dead battery as a capacitor. I've done this a few times on old junk batteries in cars, bikes and lawnmowers.

keep two things in mind. The charger I've got is a 200 amp Schumacher, and there is a chance of the battery blowing up, and spraying acid all over everything within 30 feet of it, in all directions. If a battery won't fully charge there is no cheap way of knowing if there is a shorted cell.

​​​​​​​FWIW, a slow charge can blow up a battery too, but you're usually not standing right beside it when it does.

 

how old is old, has manual foot?? if so, a dry cell 12v battery will start it or two 6v lantern batteries in series, i used to run a honda 305 pretty much over built (another story) but i had a dry cell 12v battery in it to save weight. actually, with the pmg system, could be push started. use a battery from a rider mower.

 

HD starter motor is 1.5kw. So, it draws about 125 Amps. You'd need a battery charger about the size of a small refrigerator to generate that kind of power.

Disconnect a charged car battery, and try to jump it with that.

 

No conventional battery charger is going to work in place of a battery, to start a bike, IMHO. A battery is a powerhouse designed to deliver a brief big surge of power, a charger is designed to supply, relatively speaking, a trickle of continuous low power. There is a gulf of difference! As TriGeezer suggests, use a charged car battery.