battery issue. possible solution?

[bagoony]

Last year I bought my '82 CB 750F from a previous owner who had just bought a new battery for the bike. The only thing is, it dies rather easily and can possibly last a whole days of riding with a full charge. One time the battery died on me at a red light and i had to walk my bike to the closest gas station about .5 miles (thank god).

Im not sure if its like this for older CBs but the guy told me not to ride slow otherwise the battery dies faster. I was thinking that the alternator could be the issue but the guy said it was in good condition. The previous owner also had a constant charger on the battery to help amplify the charge while the bike was on. I have no idea what it was, but he didnt sell it to me with the bike.

Any advice? I want to ride with peace of mind instead of constant paranoia of my battery dying .

Much Obliged

[Hellbilly429]

Charging systems are weak in the dohc cb 750s, I would check that first. Easiest way to check to see if it's charging properly is to take a dmm or voltage meter to it (in dc mode) and run the bike up over 3k rpms and check to see if the voltage goes above 13 volts. If it does, then I'd take the battery to the nearest parts store and have them check it to makd sure it's not just a dud.

[shinyribs]

Battery tenders, or maintainers, are pretty cheap. The one harbor freight sells for $10 have held up well for me.

Best thing to do is just check your charging system. Its true that the bike wont produce any charge at idle, but by 2000-2500rpms it should be putting out at least 13.5-14 volts measured at the battery terminals. Once again, the cheap $5 volt meters at harbor frieght work fine for this.

Check your voltage at idle with the key off, then start and Rev the bike to see what you have. It may be faulty components or it could just be loose or corroded connections on the charging harness connections.

[shinyribs]

Hellbilly ninja'd me! I'm going back to work and let him handle this. LOL

[Hellbilly429]

Lol. Sorry ribs, you were much more helpful than I was

[TOOLS1]

The PO was full of BS!!!! You should not have to ride fast to keep the battery charged! You should not have to keep a charger on the bike at all times when not riding!!!! The DOHC bikes are known for bad charging systems! You can download the Factory Service Manual for free from the manual thread at the top of the home page here. It has detailed instructions on testing the charging system.
TOOLS

[bagoony]

Thanks everyone. Going to do some testing once I get home tonight! I'll give an update once I figure out the solution.

[Truck]

Also take a good look at your connectors. I am having the same problem, and every time I pull apart and clean a connection it gets a little better.

[sgtslag]

Hooking up a smart charger, like the Battery Tender Jr., between rides, is a very good idea:  it tops off the battery's charge; it prolongs the life of the battery by keeping it at 100% charge, all of the time; it will keep your battery healthy, even if you forget about it, and leave your bike sitting for longer than you had planned.  I would also recommend an AGM battery, if the current one is bad:  maintenance free, no electrolyte to top off, higher starting voltage, and they usually last 6+ years.  I've only had conventional batteries last me 2 years...  The AGM will cost about twice as much, but it should last three times as long -- they're a better investment over time.

I would also recommend installing a volt meter on your bike.  It can tell you at a glance, if your charging system is working -- that "piece of mind", you are looking for.  They range from $4 to $50+, depending on what type you get.  Cheers!

[bagoony]

Update: So it turns out it was my stator. Took a look at it and the coils were pitch black...also the gasket was missing.