battery boost

[Thufir Hawat]

Do those 400 amp battery boosters work for motorcycles?


http://www.walmart.com/ip/Schumacher-Instant-Power-500-Peak-Amp-Jump-
Starter/13005748


this one is 500 amp, but I've seen 400 amp. Will too many amps fry the
motorcycle?


thanks,

Thufir

[Rob Kleinschmidt]

Answer: it all depends. I wouldn't expect to have
trouble unless I had a short in the bike's electrical
system. If I did have a short or other serious loss
of electrics, I might expect to have some trouble(s).

If the battery is low but still shows signs of life,
a jump should be OK.

If the battery is old or won't take a charge, I'd just
replace it.

If the battery very suddenly went flat, I'd try to find
out why before I did anything else.

In any case, exercise caution when doing the initial
hookup and be prepared to disconnect quickly if need be.

[Mark Olson]

No. It's just a sealed lead acid battery in a plastic case, with
a integral low current (less than 10A) battery charger to recharge
its own battery. So it's exactly like jump starting your bike from
another bike battery. If you don't reverse the polarity of the
cables, it will be fine.

Hint: follow the directions carefully- it's a good idea to connect
the positive jumper cable to the positive battery post first, then
clamp the negative jumper cable to an exposed bare metal part of the
engine or frame, so that any sparks produced are not by the battery,
where hydrogen gas can be present. Your bike's battery SHOULD either
be sealed, or remotely vented, but I've seen plenty of bikes where
the vent hose is missing so any H2 gas coming out is near the battery
itself where it could be ignited by a stray spark. And when
disconnecting, remove the negative cable first, then the positive.

[David T. Ashley]

It won't do damage unless you have a pre-existing serious electrical
fault in the motorcycle; and in that case it will only do damage
_faster_ than a motorcycle battery would.

A battery is characterized by two things:

a)Its open-circuit voltage (determined by the chemistry and number of
cells).

b)Its internal resistance, i.e. how much its voltage drops with load.

The voltage output of such a device will be approximately identical to
your motorcycle battery ... just that when you load the battery (i.e.
take current from it), its voltage will drop less.

You might imagine this as just like the difference between a AAA-cell
and a D-cell. Both of them will read the same voltage on a voltmeter.
Just that the D cell can provide a lot more current for longer. You
can wire up a D-cell to be used in any application where an AAA-cell
could be used.

Now, in principle, you could construct a device that would be damaged
by too stiff of a battery (one with the same voltage but higher
ampacity), but in practice this won't happen. If you put an
automobile battery in your motorcycle, the most you would notice is
that the headlight is brighter and the starting is quicker. You won't
cause any damage with a "stiffer" battery of the same voltage.

However, there are two scenarios to be cautious of:

a)If you connect such a device to your bike, it is possible that a LOT
of current will flow into your motorcycle battery if it is discharged
or defective. You want to make the connection at the battery.

b)Any short circuit or electrical fault will be a disaster. These
devices provide enough current to arc weld.

DTA

[Eiron]

It's not just a good idea. It's essential that you connect the positive
lead first and disconnect it last. But not for that reason.
The chance of igniting hydrogen while jumpstarting a vehicle is about
one in a brazillion. The chance of accidentally touching some exposed
metal with the red clip is about one in a hundred; the consequences
can be severe if the ground wire is already connected.

While on the subject, here are some tricks you can try at home.
Jumpstart a piece of wire wool. (Search for 'wire wool battery' on Youtube.)
Throw a lit cigarette into a can of gas. (It never ignites.)
Use your phone while filling up. (That never ignites either.)


--
Eiron.

[Futility Man]

On Mon, 21 Jan 2013 21:16:17 -0800, David T. Ashley <das...@gmail.com> wrote:

>It won't do damage unless you have a pre-existing serious electrical
>fault in the motorcycle; and in that case it will only do damage
>_faster_ than a motorcycle battery would.

Not picking on you, DTA, but everyone has failed to realize that if a short
exists that would cause catastrophic harm to the bike, the bike's battery would
already be stone dead from that short circuit. Unless, of course, the lead from
the solenoid to the starter connection was grounded, in which case it would
release its internal smoke pretty much instantaneously when the start button is
pushed..

--
Futility Man

[David T. Ashley]

On Tue, 22 Jan 2013 07:36:02 -0500, Futility Man <nu...@futile.org>
wrote:

You are free to pick on me.

You are correct. Both a motorcycle battery and a jumper pack can
deliver more current than any wiring in the motorcycle can take,
including the starter motor wiring through the solenoid. So we are
talking "shades of instant".

It is the same question as whether I'd feel more pain being 12 inches
from an artillery shell detonating versus being at ground zero when a
nuclear weapon detonates. Both processes are effectively instant
("shades of instant"), so any distinction is minor. I don't think I'd
feel a lot in either case.

DTA

[David T. Ashley]

On Tue, 22 Jan 2013 08:19:07 +0000, Eiron <Evelyn....@live.com>
wrote:

Electricity can be major fun:

http://www.youtube.com/watch?v=E9tBXIbME5o

http://www.youtube.com/watch?v=mh7VHcuaPCg

DTA

[Tom $herman]

On 1/21/2013 11:16 PM, David T. Ashley wrote:
> b)Any short circuit or electrical fault will be a disaster. These
> devices provide enough current to arc weld.

Been there, done that (arc weld mark on a socket wrench) when
reinstalling a battery in a MG Midget. Come to think of it, I would
have been ahead if I had burned the car up. :(

Also charged the battery in my TW200 with an automotive charger on its
2-amp setting with no apparent issues (a bit of water came out of the
vent hose, but I may have overfilled it slightly with distilled water,
since it is hard to see the electrolyte level through the more
translucent than transparent case).

--
Tom $herman

[Thufir Hawat]

On Mon, 21 Jan 2013 19:14:46 -0600, Mark Olson wrote:


> Hint: follow the directions carefully- it's a good idea to connect the
> positive jumper cable to the positive battery post first, then clamp the
> negative jumper cable to an exposed bare metal part of the engine or
> frame, so that any sparks produced are not by the battery,
> where hydrogen gas can be present.

Is this also the proper procedure for jump-starting from a vehicle? It
seems like I've seen people connect the positive first, then negative,
and boost fine(?).



-Thufir

[Thufir Hawat]

On Mon, 21 Jan 2013 21:16:17 -0800, David T. Ashley wrote:

>>this one is 500 amp, but I've seen 400 amp. Will too many amps fry the
>>motorcycle?
>
> It won't do damage unless you have a pre-existing serious electrical
> fault in the motorcycle; and in that case it will only do damage
> _faster_ than a motorcycle battery would.

It's just a 50cc chinese Lifan scooter. The battery guy came buy and
recomended at YTX9BS would fit better (the battery in there is a bit
tall), but we checked that the battery was charged and that there wasn't
a draw draining the battery when the scooter was off, then it started up
fine.

Kinda weird, I can only guess that it was due to cold weather.
Everything is running fine now, I bought a trickle charger from the
battery guy.

He was going to rig up a secondary battery as a booster, because he said
that those booster packs are only good for a few starts before the
internal battery dies, and that they don't recharge properly(?). In any
event, that wasn't necessary, and, if I have problems in the future, I
can just charge the battery.


thanks for the responses,

Thufir