Battery problem - 1983 Honda CH750

[JayT]

Hi all,
I'm new to this forum and figured it would be the best place for me to get help on this.

I bought a 1983 Honda CB750 a couple of days ago and started working on it,
When I went to see it, the guy fired it up for me, sounded great, a little shaky but nothing a good tuneup won't fix.

The battery was dead so we had to boost it, therefore the first thing I did when I got it home was to go to my honda dealership and get a new battery for it. The guy charged it at the shop and I installed it without any problems but it's simply not working. there is NO power, no blinkers, lights and the bike won't fire up.

Any idea what it could be? I don't think it's the alternator because when we did fire it up, we didn't have to keep charging it, it worked fine and I rode it for a while.

Any help or thoughts would be appreciated, Thanks!

[TOOLS1]

Welcome to the forum. We'll sure try to help you out. First I would check the battery cables, and their connections. Then I would check the main fuse, and wires. You will need a test light, and maybe a ohm meeter. If you do not have them. You can get them at any auto parts store, Sears, or hardware store. They are not very expensive, and very handy to have. Also you should have a shop manual. There might be one still available for download in our manual section, but we have been having problems, so I don't know if it is still there.
TOOLS

[doughboy]

Try cleaning the cable ends with a wire brush or flat file.  Clean the new battery posts the same.  Make sure your bolts are also replaced.

[LukeM]

I also recommend a Battery Tender or similar device to keep the battery in tiptop charge.  They supply about an amp or so to charge, then drop down to a trickle charge to keep it topped up.  It wouldn't hurt to get some battery post protector gel/spray to seal things up, once you get all the charging/battery issues sorted out. ONLY use distilled water when adding water to the battery cells.

Typically, a battery at rest in the bike should have between 12.5 and 13.5 volts. When running, the alternator supplies about 14.5 volts. Assuming the charging system is in good shape, you won't see any significant current from the system until the engine gets above 2000 rpm.  Then the charging begins. Per the FSM, the alternator supplies 6 amps at 1500 rpm, and 18 amps at 5000 rpm.  These levels are regulated by the rectifier/regulator so as not to overcharge the battery too quickly. Charging rate for the battery is 1.4 amps maximum.

Luke M

[mikefootusa]

Check out this "trickle charger" work-around.  Plan on hooking up one of these to a cigarette plug end and be able to just plug it into the new cigarette outlet I installed in my toolbox today.

http://cycletips.blogspot.com/2007/04/trickle-charger-simplicity.html

[sgtslag]

A couple of caveats on using these 'free' chargers... They are likely not regulated, which means their output voltage can vary, depending upon the load they're connected to.  Applying too high of a charging voltage can damage the plates within the battery, shortening its life dramatically.  Secondly, they can boil off the electrolyte, if you leave them connected for weeks, or longer, such as can occur during Winter storage.

Smart trickle chargers, such as the Battery Tender Jr. (a 0.75 amp charger), are microprocessor controlled; they monitor the level of the battery's charge, auto-magically adjusting the charging voltage applied, to properly, and fully, charge the lead sponge plates within the battery, without damaging them.  The Battery Tender Jr. can be purchased, on sale, for around $28, or less.  For me, it is better to do it properly, even if I have to spend more cash.

WebBikeWorld.com did an article on smart chargers.  They plug their bikes into Battery Tender Jr. chargers, after every ride.  By doing so, they have achieved 5+ years of service out of their lead-acid, flooded batteries -- normal life-expectancy for such batteries tends to be more like 2-3 years...

The Battery Tender Jr. (link) is one of the older smart chargers:

Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell).

Complete 4-step charging program (Initialization, Bulk Charge, Absorption Mode, Float Mode).

Automatically switches to float / maintenance voltage after fully charging the battery.

If the battery voltage drops too far under load, full charger output power resumes.

Solid state two color LED indicates stage of charger.

Spark proof.

Reverse polarity protected.

12' output cord.

5 year warranty

For me, the features listed above, are worth the cost.  I am in favor of recycling, and re-using, but this is a serious matter, due to the potential for the fumes to explode should there be a spark from me connecting the charger, and because I want to plug in my batteries for the Winter, and forget them until Spring, without worrying about boiling off their electrolyte.  However you proceed, I wish you the best.  Cheers!

[rich]

I installed a Battery Tender JR on my bike this weekend. Plug and play. The connector tucks away between the side cover and the seat but it's easy enough to get to. Just roll it into its parking space in the garage and plug it in. Easy as pie. I'd like to find another connector that I could use to tap into the battery to charge a cell phone while I'm riding (phone would be in the saddle bag). Have you seen the connectors sold separately?

[sgtslag]

I thought they offered them separately, in the past, but I haven't looked in quite a while.  Have you searched on e-Bay?   I believe I have seen them listed there.  Otherwise, try www.batterytender.com to see what they offer.

If that doesn't work out, you can always install a cigarette lighter type outlet on your bike's battery posts:  make sure you install an in-line fuse holder with a fuse large enough for your charging needs, but not much larger (go one amp more than what you will need), and route it out the back, and side, of your seat, at a convenient location.  Be sure to prevent the wires from getting pinched!  That could lead to shorting the battery...  Keep the in-line fuse holder close to the battery, itself.  Cheers!

[Piute]

Radio shack have the same set-up

[rich]

rich wrote

I installed a Battery Tender JR on my bike this weekend. Plug and play. The connector tucks away between the side cover and the seat but it's easy enough to get to. Just roll it into its parking space in the garage and plug it in. Easy as pie. I'd like to find another connector that I could use to tap into the battery to charge a cell phone while I'm riding (phone would be in the saddle bag). Have you seen the connectors sold separately?

I found a connector at O'Reilly Auto Parts the other day. It's a standard cigarette lighter socket / power port that's made to attach to trailer lights! I noticed the connector looks the same as the battery tender connector coming off the bike's battery so I thought I'd give it a try. It plugs right in and the polarity is correct. It's item number 10722 and it was $4.99.

I took a spin today and used it to charge my camera. The connector is long enough to reach my saddle bags so everything is stowed safely.

[sgtslag]

Double-check to make sure there is a fuse on that circuit!  Without a fuse, you could draw too much current, and the wires could heat up, and start a fire.

I believe there is a 1A(?) fuse inline with the Battery Tender Jr.'s connector, so as long as your accessory (camera, in this particular case) does not draw more current than the fuse can handle, it will work.  I would not recommend installing a larger fuse in the BT Jr.'s connector:  the wires were designed for 750 mA continuous current flow; if you run more current through them, you may heat them up...  Cheers!

[rich]

Thanks for the tip! I'll have to keep that it mind, I don't want to be using that port for anything but a USB device.

The wires are the same gauge on both the power port and the battery tender connector. Most USB devices are 500 mA @5 volts so I'm well under the 750 mA. Just don't want to go sticking a cigarette lighter in there!

[Piute]

 Very nice to have