Help! Flat battery

**hamie1** · 4th June 2008, 22:05

My bike has been sitting behind mum and dads huge pile (and I mean f'n big) pile of fire wood in the garage and I can only now just get to it and I've been out of town for a few months and the battery is dead.

The bike is only about a year old. Argh

How do I restart it without buying a new battery?

Jump start it? Off a car possible?

Can I crash start it? How?

HELP.... PLEASE

**Ragingrob** · 4th June 2008, 22:08

How dead is it? Any signs of life? You can jump start it, just make sure the car isn't running. Crash start it by getting up some speed, chuck it into 2nd and drop the clutch.

Good luck

**hamie1** · 4th June 2008, 22:12

Still got a bit of life thanks.
Don't want to drive over to Katikati and find out I can't dump the car there and not ride the bike home.

**Ragingrob** · 4th June 2008, 22:29

Yeah that'd suck, should be able to bump start ok by the sounds of it. Then go for a nice long ride to charge it back up

**robinm** · 4th June 2008, 22:37

to jump start or crash start it, motorcycle charging systems, in general,are delicate things, designed to keep a battery charged, NOT to charge a flat battery. The problems that you MAY have if you jump or crash start it include a fried voltage regulator, a burnt out alternator, burnt out wiring or if you are lucky, no problem at all. The best thing you can do is take a charger over there and charge the battery up before starting the bike. Ideally a bike battery likes a slow charge of about 1 to 2 amps to bring it up correctly but that can take more than 24 hours for a well flat battery, so you may have to give it a short higher amp charge, say 6 amps for 4 hours, not ideal but it should bring it up enough to fire it up.

**FilthyLuka** · 4th June 2008, 22:42

Originally Posted by robinm

say 6 amps for 4 hours

make sure you keep an eye on the battery temperature if you do this

**CookMySock** · 4th June 2008, 22:51

you can jumperlead it off a car no worries.

Can you get some help to push it up a nearby slope ? Then hop on and point it down the slope, choke on, ign on, kill off, select 2nd gear, pull clutch in, get a push up to jogging speed, crack throttle open slightly, stand up, and simultaneously let the clutch out and sit down hard on the seat. Be ready for it to zoom off. Don't drop the bike !!

Really the smartest thing to do is to boof a charger on it all night and start it normally.

DB

**HungusMaximist** · 4th June 2008, 22:53

Originally Posted by FilthyLuka

make sure you keep an eye on the battery temperature if you do this

Best thing to do is get yourself a trickle charger which charges at 0.5 amps an hour or even better, a smart charger where it will maintain & test the battery, charge it and will know when to stop charging to avoid over charging.

If you do decide to use a car charger (which has a high charging rate) like Luka said, just keep an eye on it, as it could over charge it and (not likely) but some tend to explode..

One critical thing you need to do is to determine if your battery is dead or not. It will most certainly hold charge if you bump start it and keeping the revs up but the last thing you want is not knowing you've got a dead battery in your bike and suddenly cuts out at the most random places (roundabout

)

**robinm** · 4th June 2008, 22:53

I neglected to add that.

**FilthyLuka** · 4th June 2008, 23:16

Originally Posted by HungusMaximist

If you do decide to use a car charger (which has a high charging rate) like Luka said, just keep an eye on it, as it could over charge it and (not likely) but some tend to explode..

Yeah, it happens...

The battery acid is a bitch to clean up.

Just use a trickle charger, put it on in the morning, take it off the next morning and robert is your aunties husband.

**rphenix** · 9th June 2008, 17:10

Originally Posted by DangerousBastard

you can jumperlead it off a car no worries.

Can you get some help to push it up a nearby slope ? Then hop on and point it down the slope, choke on, ign on, kill off, select 2nd gear, pull clutch in, get a push up to jogging speed, crack throttle open slightly, stand up, and simultaneously let the clutch out and sit down hard on the seat. Be ready for it to zoom off. Don't drop the bike !!

Really the smartest thing to do is to boof a charger on it all night and start it normally.

DB

No doubt charging and/or replacing battery is a good thing but I do recommend a run start if nothing more than the experience the advantage is you can then ride the bike instantly.

Personally I reckon everyone should be able to run start a bike at home so they know what to do when they have a flat battery out in the whops.

After owning an XR for years that sometimes sat inside the shed for awhile (I had more than one) I was a master of the run start

If your worried about run starting then do so in an easier gear than say second, 3rd/4th or something? that will make the engage much smoother but also means it requires a bit extra length to run. The advantage of 2nd is however you can run it while in neutral, jump onto the bike quickly click it up a gear into second (with the clutch in) and let the clutch out easily. Saves you having to get the bike up to speed by pushing it with the clutch engaged which takes a fair bit more work esp with bike gear on.

**davereid** · 9th June 2008, 17:30

Originally Posted by DangerousBastard

you can jumperlead it off a car no worries.

Your motorcycle has a shunt regulator. You can jump it off a car, but you have to remember a few things.

The MOST IMPORTANT thing is NEVER start the car !

If you start the car, its alternator will be able to produce 60 to 80 amps. This current is intended to go into the cars battery, but, if you are connected by jumper leads, it will go into the bike battery too.

And your bikes shunt regulator will attempt to regulate the cars alternator.

When it loses, you get to buy a new regulator. If you are really lucky you can buy a new stator too.

So.. Ideally, (At least from the bikers point of view !) to jump a bike off a car, disconnect the cars earth strap first, then connect bike and car batteries in parallel.

This can cause a bit of grief in the car, central locking might lock the car, security radios lock, fuel pump crash relays can go into crash mode.

So, connect NEG to NEG both batteries, both vehicles OFF, car keys OUT and DRIVERS DOOR OPEN.

Then POS to POS.

Wait a bit - car battery will be charging bike battery.

Start bike.

Wait a bit - shunt regulator, rectifier and stator are being given a rest as bike alternator attempts to charge dodgy bike battery, assisted by car battery.

Don't let an aircooled bike overheat, but leave connected as long as you can.

Stop bike, disco leads, restart bike, go home.

**CookMySock** · 9th June 2008, 20:52

Originally Posted by davereid

Your motorcycle has a shunt regulator. You can jump it off a car, but you have to remember a few things. [snip]

Many thanks davereid. That would have got me.

Remember people, the GT250R is a massive bike. Push starting an XR200 is one thing, a full size road bike is something quite different.

I tried to push start my GT650R down my slightly inclined driveway - total failure! Its just too big and heavy. If I had a helper, yes.

DB

**ynot slow** · 9th June 2008, 22:09

Agree with the XR200 and my older TS and ER 185,if crash starting would push in neutral,jump on sidesaddle,flick gear lever into 2nd without clutch,usually fired up clutch in and throw leg over,was impressive to watch,and easy as to look impressive.The sidesaddle wat was shown to me by neighbour into mx,he used technique on his RM125.
Mate used to travel monday to Palmy leaving about 6.00am,usually got call about 6.10am to help start,used tow rope once behind the car(no leads)was hard to push a GSX750 25ys ago lol,many a time cursed him,bike would be ok on friday returning in afternoon,but monday it would flood and no go.Worst thing was he was a sparky,could suss out low voltage in charging system,but never got a battery.