How Do I Jump My Battery

[alanmcorcoran]

If you have a sketchy battery, it is definitely worth investing 30 minutes or so into learning how to "push" start the bike. There are detailed instructions on here elsewhere, so I won't repeat them. The thing is, it's kind of tricky to know just how bad your battery is, and if it poops out when you aren't home, it's not so easy to hook up the charger, tender or jumper cables. A slight downhill is pretty much all you need. The pro's recommend using third gear to start it, but I was able to start mine in any of the first three after some practice. When mine was acting up and stalling, I used to routinely restart it without pressing the starter button to conserve the battery power.

I have also re-started the Strat this way, but it requires a steeper hill.

[kaput]

I have 3 chargers, I bought 1 and people keep giving them to me. One came with my GZ and its pretty nice, it will fully charge your battery in half an hour or so. it is called a "Husky Smart Battery Charger" and comes with instructions. Pretty cool and electronic as opposed to the old style with the needle that you can never tell if its 100 percent or 0 percent and you have to let go overnight.

If I were you I would push start it and drive it around with the headlight beams on low for an hour or so, that should charge it for the price of however much gas you burn in an hour or buy one of my old chargers.

[Easy Rider]

Originally Posted by kaput

If I were you I would push start it and drive it around with the headlight beams on low for an hour or so, that should charge it .........

You would think it would but experience tells me that it WON'T.....unless you take it out on the highway for an hour maybe. The electrical system just doesn't have the capacity to completely recharge a dead battery, at least not from just puttering around town.

Once your battery gets near to fully discharged it NEEDS to be fully recharged.....and the sooner the better.

AND despite what the charger maker might tell you, it is NOT a good ideal to completely recharge a dead battery in only a half an hour. You can't change the laws of physics and chemistry and charging that fast is HARD on the plates and can release enough gas to cause an explosion.

[alanmcorcoran]

One more tidbit on this - the battery tender people do not recommend you use a tender as a charger. I was kind of surprised about this as I assumed that, after a while a tender would "bring up" a battery to full charge, but they told me that once the battery is down a certain percentage (I forget the actual measurement) the tender won't work.

Based on their advice, I bought a charger to recharge my Strat battery after I left the headlight on for three days. That was months ago. So far so good. I used the low (2 amp?) setting and let it charge overnight.

[Jere]

Is it correct to say that simply applying a voltmeter to the battery will tell if the battery is good or not? What range am I looking for? 12 +/- 1/2V or so?

[mrlmd1]

12.8v is a fully charged battery. 12.0 is low, no good. 10v is 80+% discharged.
The only way to tell if a battery is good is to put it on a load tester - if you don't have one, after you charge it up overnight, take it to a battery store and have them test it.
If you get a new sealed 12v battery, make sure you charge it up fully before you put it into service, otherwise it'll die real quick.

[Easy Rider]

Originally Posted by mrlmd1

12.8v is a fully charged battery. 12.0 is low, no good. 10v is 80+% discharged.
The only way to tell if a battery is good is to put it on a load tester -

The basic answer is NO, you can't tell just by measuring the "no load" voltage.......unless it is in REALLY bad shape, as the 10V mentioned above.

It is 12.6, Doc. 2.1V X 6 cells.
But meter errors can give readings from 12.2 to 13 V. or so.....and immediately after charging, they can read slightly above 13 for a few minutes.

The headlight and starter are good load tests.
The voltage at the battery should drop no more than a couple of tenths with the lights on (but NOT running) and it should not drop much below 11V with the starter running.

Probably the best test of a battery is whether or not it still DOES what it is supposed to DO.