Battery

DevonCbx · Post by **DevonCbx** » Thu Feb 21, 2008 9:06 pm

I have a very used battery that really does not hold charge. If the bike is warmed up I will get one start out of it. I am in the process of purchasing another battery. My question is: I noticed my charging system does not charge the battery. If the battery is at the end of its life, will it not take a charge. If I had a fresh battery, would that possibly correct the problem fo the charging system not functioning? Also while the bike was warming up, it seems the volt meter on the bike was slightly increasing.

Thanks Duane

Terry · Post by **Terry** » Thu Feb 21, 2008 9:23 pm

My volt meter doesn't work reliably until the revs pass 3,000. After a good warmup, it does register a bit lower at idle but quickly comes up to 13+ after the revs go up. Most bike alternators don't recharge the battery until the revs are higher than an idle. That's yet another reason not to just warm the bike up in the garage for a few minutes once a month during the winter months. They need riding to stay charged, or a good battery tender, that is of course, if all the other necessary items are in good shape, alt clutch plates and brushes etc.

alimey4u2 · Post by **alimey4u2** » Fri Feb 22, 2008 3:14 am

Duane, to add to Terrys most excellent advice, the CBX does not have a permanent magnet as the rotor. It therefore needs power to excite the magnetic field. If your battery is dead flat or even poor, the field may never be generated (or be marginal) & the charging system will not function.

Rick Pope · Post by **Rick Pope** » Fri Feb 22, 2008 8:02 am

Duane, I posted here a while back about using an ammeter rather than the volt meter to check whether the alternator is doing it's job. Imagine that the battery is a bucket of "juice". The volt meter tells you the level of juice, while the ammeter tells you how fast it's filling, or draining.

While the volt meter is fine for keeping an eye on things, once you have a problem, you really need an ammeter to see what's going on. I use a simple inductive ammeter from K-D Tools. See if there is current flow at idle and again at 3-4000 rpm to tell whether you are charging.

Just after start-up, it's normal for the volt meter to indicate slightly low voltage, since you just drained out some juice. And since the volt meter doesn't indicate current flow, it takes a while to really tell whether you are charging or not.

Mike Nixon · Post by **Mike Nixon** » Fri Feb 22, 2008 10:35 pm

Rick Pope wrote:Duane, I posted here a while back about using an ammeter rather than the volt meter to check whether the alternator is doing it's job. Imagine that the battery is a bucket of "juice". The volt meter tells you the level of juice, while the ammeter tells you how fast it's filling, or draining.

Rick, you mean like this? :)

Rick Pope · Post by **Rick Pope** » Sat Feb 23, 2008 5:48 pm

Yup, that's a very good picture of what I was trying to say. I can't believe how many times I've seen folks trying to diagnose an electrical problem using only the volt meter. Duh......

The K-D inductive amp meter is only a few $ and saves soooooo much time.