How to Jump Start a Motorcycle Battery From a Car

[e-beach]

Manufacturers do not recommend attempting to jump start a motorcycle battery from a car.
The reason is that car batteries are much larger and have a much higher amperage (more power) and can damage a motorcycle battery.
Life doesn't always cooperate, however, and you may find yourself with little alternative.
Can anyone here give some advice ?
how to jump start a motorcycle battery from a car without damaging the bike and with little risk to the battery??

One thing I have learned around her is the volts are volts....

When I used to do that I never had any problems jump starting from a good car battery to a dead motorcycle battery. I would just run jumper cables from the car battery to my motorcycle battery and let it sit for a time. 30 minutes or more if I could. Then without starting the car I would start my motorcycle. No need to start the car because of the higher Ah in the car battery allowed my to pour some of that into my motorcycle battery. . Provided, or course, both batteries were the same voltage ie: 12 volts.

Unless the car battery is weak, then start the car, let the car idle while the car battery and the motorcycle battery are jumpered together and let the car charge your motorcycle battery.

Once your motorcycle is running again, then I would figure out why my motorcycle battery was drained.

Anyway that is what I used to do.

 

[potatorage]

Unless the voltages were different then I can't imagine why it would not work.

 

[Hillhater]

Many modern car manufacturers do not recommend jump starting from other cars either ??
I dont understand why, other than possible sensitive computer gear on modern vehicles.
however it has never stopped me on several occasions to help family /friend out of "dead battery" syndrome

Incidentally..in the past few years i have encountered more failed batteries in cars, than in the previous 50 years of fooling with vehicles. ?? It seems that 3 yrs is about the most you can expect from a lead cell before it dies.
I literally have a collection of 8-10 (lost count) of wasted 12 v lead car batteries in my garage at the moment !

 

[ZOMGVTEK]

Most everything does not recommend being jump started, or started while connected to a battery charger. It's mostly just to protect the manufacturer from people screwing it up, or really odd issues. If the battery is internally shorted, and you jump it with a good car battery, very high currents can really bubble up the electrolyte. If you leave the jumper cables connected for a very long time like this, for whatever reason, the case of the battery could melt or deform enough from the heating to pour the electrolyte everywhere. If the battery was internally open, or nearly, an older battery charger could put relatively high voltage on the electrical system when unloaded, or extremely high noise due to the largely cheap unfiltered nature of car battery chargers/starters.

For the average situation, where the battery being jumped is OK (which might not always be the best assumption if the battery needs a jump), it won't care at all. Just don't leave the cables connected much longer than required, and don't reverse them. If you see a very large spark when you connect the cables, something might be wrong.

Never assume an alternator will recharge a battery after it's been deep discharged. They do fine with keeping a relatively full battery topped off, but thats about it. It will likely charge it enough to restart fine, but might be only at 60-80% SOC. You really need a very long low current charge to bring it back up.

 

[ohzee]

I literally have a collection of 8-10 (lost count) of wasted 12 v lead car batteries in my garage at the moment !

I had something similar from using lead for trolling motors. Not long ago I found a local place that takes cores and they
paid 5-10 each depending on what kind of shape they are in. So if nothing you have a free dinner sitting there.

 

[Takemehome]

Manufacturers do not recommend attempting to jump start a motorcycle battery from a car.
The reason is that car batteries are much larger and have a much higher amperage (more power) and can damage a motorcycle battery.
Life doesn't always cooperate, however, and you may find yourself with little alternative.
Can anyone here give some advice ?
how to jump start a motorcycle battery from a car without damaging the bike and with little risk to the battery??

Negative is on the frame.
Disconnect the negative from the motorcycle bat.
Jumpstart with positive on positive and negative on frame.
When the motorcycle is running remove jumpers and reconnect the negative.

 

[Dauntless]

Had the motorcycle repair class, people brought in bikes that hadn't run in years but didn't want to replace batteries until AFTER that bike was running. We jumped from a car BATTERY all the time. Not a running car. After years of working in film/tv/video I've learned that a reluctant battery often responds better to having another battery connected to it than it does to charging. So I'd hook these old batteries up to a car battery without the car running, they often came back to life. Er, for a little while. Doing this for a time before actually trying to start the bike often meant the battery would be okay about as soon as the bike was running. Again, for a little while. You'd need a new one before long.

 

[Sunder]

A significant number of bikes use 6v batteries rather than 12v batteries, so that's one thing to check for.

To be safe, I reckon the way to do it is:

1. Remove battery from bike.

2. Hook up bike battery to car battery

3. Stay there to ensure battery does not get warm or gas

4. Give it a couple minutes to charge

5. Reattach to bike

6. Start bike

7. Let the bike's alternator finish the job off.

I wouldn't risk jumping directly. There's very little advantage, when bike batteries weigh like 3kg tops, and can be removed in less than 30 seconds, usually.

That said, bike batteries are so small, I've gone from won't even crank, to starting up in less than 2 minutes on a 6A charger.

 

[dogman dan]

I'm such a doofus, I always just used the kick starter. I suppose by now bikes come without one, but a push start should be quite easy too if you have a second person for a big bike. Once home, I might put the bike on a battery recharger.

 

[itchynackers]

Cant you just push it and pop the clutch?

 

[e-beach]

I'm such a doofus, I always just used the kick starter. I suppose by now bikes come without one, but a push start should be quite easy too if you have a second person for a big bike. Once home, I might put the bike on a battery recharger.

A kick starter was always a good thing on my motorcycles. If for some reason the battery went dead...stomp..stomp...stomp until the engine started. Being able to roll it down a hill for an easy start was always a luxury. But, my bikes were never over 500cc.

ice_robin, how many cc's is you motorcycle?

 

[Dauntless]

I'm such a doofus, I always just used the kick starter.

No, it's the Chinese doofus that replaced the kickstarter with the fragile recoil start. Rope breaks in 3 pulls, now what do you do?

 

[dogman dan]

Or maybe even something that can't be push started? I never tried it with my scooter, that had an automatic transmission. Don't know if it would even push start at all. I used to push start a moped all the time, but that was easy. It was quicker than doing the pedal start thing.

 

[pdf]

I've started dang near everything from a car battery; 4 wheelers, motorcycles, jetskis (hard to get car to float, but OK after that). No problems there.

The one time I had a problem was trying to jump a diesel tractor from a car. Tractor batteries are huge. The starter drew so much current, the jumper cables got very hot. Don't recommend that. So volts are volts, but you need to make sure your cables, battery can handle the amps. Going from a car battery to a smaller battery; no problem. The other way round, not so much.

EDIT: By "smaller battery" I mean fewer cranking amps. Clearly the voltage needs to be the same. ALWAYS check the voltage before jumping anything.

 

[Punx0r]

I have a car surge protector (recommended for jump starting and welding) that *claims* it allows a 12V vehicle to be jump started from a 24V one. I've not dared try it...

 

[e-beach]

The one time I had a problem was trying to jump a diesel tractor from a car. Tractor batteries are huge. The starter drew so much current, the jumper cables got very hot. Don't recommend that. So volts are volts, but you need to make sure your cables, battery can handle the amps.

Very good point!!!

It triggered a memory of when I put a 1965 v8 Mustang engine into my 1955 Ford F150. After all the modifications, everything in it's place, I bolted the original 1955 ground strap from the truck body to the block of the V8. But when I turned the ignition key, nothing happened except the ground strap started smoking and melting.

Fortuitously, one of my friends knew the head mechanic of a local Ford dealership. I got his number and called him up. He understood immediately. "Your ground strap isn't hefty enough."

"What?" I said. "It is only 12 volts."

"Yea, but you are drawing enough amps to melt your ground strap. You need a heavier ground strap, or maybe a few more the same size that you have." "In any case your amp draw is too much for what you have."

I went to a junk yard and got a heftier ground strap and got my truck going.

In the end he was right because if you are drawing amps, you need enough metal in your wires to do the job without melting your wiring.

Thanks for reminding me!

 

[Dauntless]

I have a car surge protector (recommended for jump starting and welding) that *claims* it allows a 12V vehicle to be jump started from a 24V one. I've not dared try it...

Oh, we're all dying to read your report on using this fascinating device. I for one will be watching right here from the safety of my computer.

 

[Punx0r]

I hope I never have to try it... I can't see how it could do it apart from trying to pull the 24V battery down nearer to 12V, which would make an instant fire... The model I have is no longer sold, this may be a clue as to why

 

[e-beach]

I hope I never have to try it... I can't see how it could do it apart from trying to pull the 24V battery down nearer to 12V, which would make an instant fire... The model I have is no longer sold, this may be a clue as to why

Or it just has a built in dc to dc converter.

 

[Hillhater]

I hope I never have to try it... I can't see how it could do it apart from trying to pull the 24V battery down nearer to 12V, which would make an instant fire... The model I have is no longer sold, this may be a clue as to why

Or it just has a built in dc to dc converter.

...capeable of 300-500 A ?

..A BIG MoFo resistor ( heater element) able to drop 12v would do the trick !

 

[Punx0r]

This is it:

http://www.amazon.co.uk/Draper-39107-12-Volt-Voltage-Protector/dp/B0001K9U9Q

I might have a look inside the case later, just out of interest

 

[Alastor]

Another idea is to use the car's cigarette lighter (180 watt max load) and have a small 12volt battery charger and charge the battery.Only thing you might need is an extra outlet for the charger.

I cant think of a cheaper and safer way to go if the manufacturer forbids jump start from a car.

 

[lpbman]

I picked up 2 Schumacher XP400 from Walmart $20 per, on sale. best impulse buy ever as I used one lead acid bat to replace a busted Harley fxdwg stock battery and the other is my go-to 12v power source. The battery is just big enough for the job, but I keep it topped off with a solar panel and in cold weather I connect the second xp400 when starting. I found upon taking the donor pack apart that the wires between the battery and the jumper cables is very thin, so for the other I added 14 gauge x2 speaker wire I had lying around to reduce voltage drop a bit.

All that to say is a few of these lying around can really come in handy and it's perfect for motorcycles.

http://www.ebay.com/itm/LOT-4-SCHUMACHER-400-AMP-CAR-BATTERY-JUMP-BOX-STARTER-BOOSTER-CHARGER-12-V-XP400-/390466986983?pt=Motors_Car_Truck_Parts_Accessories&hash=item5ae9a563e7&vxp=mtr

tl;dr booster packs are handy