[Closed] can you use a car to jump a motorbikes flat battery?

If it's all 12V then yes you can, and you shouldn't fry it.

Before that I'd try checking that the spark plug has a spark (it should be easy enough to tun over by hand with the plug out) and bump starting it (I'm guessing that being a modern one it doesn't have a kickstart)

If it's making a 'clunk' on the button then yes, a flat battery is most likely, that or a dead starter motor or starter relay.

Just be glad it's not a 22 year old two stroke like the one I've just got in from the garage from!

think it may be a bit too heavy for him to run down the street and then jump on it, and not sure how you 'turn it over by hand with no plug' (i dont do engines) 🙂

thanks a lot, ill try the jump leads tomorrow.

Push-starting a bike is fairly simple, especially if you've a slope you can ride down. Ignition on, get a run up, pull in the clutch, pop it into 2nd and let the clutch out.

Yes as above both are 12v bike just lower capacity. Think about the AA bloke he comes with a mahoosive battery in the back of the van for jumping cars, still just 12v

Embarrassingly I bumped my R6 for nearly a year as I was too tight to stump up for a new battery. No bikes are too heavy if they're balanced. Just run down the road, hop on and as your arse hits the seat drop the clutch in second. Course, in the end, my battery was so ineffectual that it wouldn't keep the engine fireing and would only run for half mile or so without a rest. Replace the batttery before you get to that point or prepare to be very tired...........

There are real risks here - the smaller battery could explode - you could ignite fuel vapour - you could short or damage the car or bike electrical system.
BTW the AA man :
a- knows what he is doing and will check the battery before jumping .
b- has a jump kit that detects shorts and has remote switch to avoid sparks
when connecting terminals .

You should : (info available on web - just not here..)

Check the battery - connections - fuse - voltage - electrolyte level if possible.
Charge the battery with a suitably rated charger rather than just jump it and expect it to carry on working.

Bump start. It should be a breeze on a VanVan, the cylinders are teeny!!!

Contrary to the above - not all bikes are easy to do so on! I had enough fun getting a 955 Speed Triple to bump on a not overly long hill... the 1200 Griso involved freewheeling down from the brow of the hill above Little Langdale to the Three Shires and dumping the clutch as I passed.

It only just did it!

The hard part was pushing the bloody thing up the half mile from the ford to the brow of the hill, on a hot day. Took about an hour and I wasn't going to have a second attempt!!!!

A new battery is only going to be 20 - 30 quid I would think, so you could just replace it and not worry....

http://www.ebay.co.uk/itm/58000mAh-Portable-Car-Jump-Start-Starter-Pack-Booster-Charger-Battery-Power-Bank-/311432632573?hash=item4882d4d8fd:g:LNoAAOSw~OVWxxyS

These sort of things are WAY better than you'd ever exepct. Used it to jump start 2 dead cars that wouldn't start of jump leads. They're small, light and very very handy to have. Mine isn't that exact one, just one i found on ebay, but mine was also an ebay jobbie.

I'd be more tempted by a battery charger than the jump starting unit - even a pretty cheap one will tell you if the bike battery is fried and will top the voltage up in a controlled fashion.

An ocassional jump start off the car shouldn't cause any major issues provided the battery isn't too dead (if it tries to turn over it's probably over 8V) just don't leave the leads on for too long once the bike has started.

My biker mates disconnect the positive battery lead when their bikes are laid up for a while

If you can wait till Sunday - borrow a charger if you can , and have a Lidl
nearby they have a charger with jump start which will do everything you need for
a very reasonable price , they also have the portable jump battery for the same price - although this is jump only not charge as well so the charger/jump is a better long term buy being a corded tool it will not be flat/dead battery when you need it it 4 years time.

Contrary to the above - not all bikes are easy to do so on! I had enough fun getting a 955 Speed Triple to bump on a not overly long hill... the 1200 Griso involved freewheeling down from the brow of the hill above Little Langdale to the Three Shires and dumping the clutch as I passed.

You should come to my house and try kick starting my 1978 Goldwing!!

To the op, yes it'll be fine but bump starting it may be an easier option.

thanks chaps. luckily the bike started this morning so hes gone to work on it, so the 15/20 min journey should help somewhat.

i didnt know these jump/starter things existed, so ill look into getting one thanks. firstly does the unit need to be plugged in to work, or can you take it to a stranded vehicle out in the country say? and what stops the unit from losing its own charge if not used for a long time?

yes, we do have a lidl nearby, so ill have a look in there too. any pics of the right lidl unit so i dont buy the wrong one if i see it? not sure i wouldnt end up walking out with a jump battery that doesnt charge, feeling all smug at my new purchase 😀

thanks again

The big blue and white one is the charger/starter - corded :
this will not work without the mains connected

http://www.lidl.co.uk/en/our-offers-2491.htm?action=showDetail&id=39457

I would get this one - in terms of practicality a flat battery parked on your drive is a pain to jump start if you cannot get another car next to yours to jump start - thats when a mains unit is handy - and obviously it will be a charger for years - long term - that one also has a diagnostic - I would guess that it shows battery voltage = more.

If you have a flat battery in the countryside - you can just use jump leads as access is often easier - not always obviously!

The small red one is obviously portable - can be used to charge devices via USB - handy - but its a disposable device life limited by its battery.
http://www.lidl.co.uk/en/our-offers-2491.htm?action=showDetail&id=39459

Basically the bare minimum is jump leads - get you going
next is having a charger - recover from leaving lights on by accident

portable Jumper pack - handy - but how often do you use it? And how long does it last?

There are real risks here - the smaller battery could explode - you could ignite fuel vapour - you could short or damage the car or bike electrical system.

How?

How do they explode ? - spark from jump lead connection ignites hydrogen/air mix from battery or in battery box if unvented or vent blocked or there are situations where water vapor boils if battery is shorted.
Fuel vapor accumulates from failed attempts to start - again spark ignites

Shorts/surges easily damage modern "clever" charging/monitoring systems - even when you switch off a modern car it may be "live" for some time.
Car manual should give procedure and point to jump connection points.

The biggest risk is from a battery that has been overcharged/boiled = lots of hydrogen around - note that this may present as a flat battery ie. it was running OK and then will not re-start.

They are real risks, but on a 125cc motorbike they're very small ones.

Right.. so those issues are common to all lead acid batteries and all jump startings.

I thought you meant specifically due to jumping from a car.

Bike batteries are often tricky to get jump leads onto - there is much more risk of a short/spark , size of battery exploding does not matter if its at arms length the acid goes everywhere - the top usually blows off.
Its happened to me with a bike battery - lucky I was wearing a helmet at the time - the acid made a mess of clothes/bike.

Ahhhh, user error then.

Yep - and I knew the risks , worked at a garage at the time but was in a hurry.

To the OP - you did the right thing to ask .

Those portable power pack/jump starters, does anyone know if they will jump start a 2.5 deisel van ?

I would buy one, but just can't see it working for some reason.

From flat no - from not quite enough juice in battery - yes if lucky.

nealglover - Member

Those portable power pack/jump starters, does anyone know if they will jump start a 2.5 deisel van ?

Maybe... But it's just a small car battery with convenient jump leads and a built in trickle charger. Mine died, so I nicked the leads off it and fitted them to a tired battery I took out of my mondeo, it sits in the garage on charge... Much better.