Electrical Wiring Question: To Chassis-ground or not .... (Aux Battery hookup)

[ChrisNYC]

To all you 'lectrical experts ...

 

I've got a 1977 KZ400 that barely puts out enough juice to blink its own blinkers. Many times I have put a spare (rechargeable) 12v battery on the luggage-rack, and used it to (separately) power a Gerbings jacket liner for short trips around the city in the cold. I always just plugged the Gerbings straight to this Aux.battery, and never had any problems.

 

Lately I've been using the KZ a lot more at night in the city. I've been thinking about adding a better/additional driving light (for those dark underpasses in Manhattan that hide a rider's best friends, you know: deep potholes, steel plates laid down at acute angles etc. )

 

Would it be ok to connect the lights similar to the Gerbings (I'd probably buy a fuse block for this 2nd battery, so the Gerbings and lights would be seperately fused ...), or should I be "grounding" this 2nd battery to the chassis somehow? I have no desire to try to "beef up" the bike's stock electrical system to handle lights and Gerbings, and no desire to "integrate" this 2nd battery into the bike's system. I want it totally separate ..

 

 

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Chris (aka Tender Vittles )

Little '77 KZ400 in the Big Apple

Black '99 RT for Everywhere Else, such as ...

[kioolt]

It would be alright to ground the second battery and fuse it for the lights and Gerbing. By just hooking up just the ground side of the second battery you would not be charging it with the bikes charging system. It is not necessary to ground the battery for what you are trying but it won't hurt anything either.

[Ken H.]

You could indeed, but I'm not sure I see the reason. You're going to have to run a wire back to your aux. battery for the positive anyway, why not just run the ground to the battery at the same time? Instead of having to mess around with finding good frame grounds, the connectors, potential corrosion points, etc.

[Art..]

It might be cheaper and cleaner to get someone to rewind the stator.

[Global_Rider]

Why not find out how many watts the stock alternator is capable of supplying.

 

Then do a load calculation.

 

Then check to see if Electrex would be of any help.

 

I can't believe an alternator not being able to handle an extra 77 watts. I'd check the performance of your stock system and see if it is up to spec.

[ChrisNYC]

Thanks for the responses, folks.

 

Global_Rider said Then check to see if Electrex would be of any help.

 

Thanks for the link, Alex. I emailed Electrex, they do not have anything for my bike . I'll check the the rest of electrical system and make sure it's up to OEM snuff, but I seem to remember nearly killing the stock battery when I hooked add'l load to it. Time for more testing ..

 

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Chris (aka Tender Vittles )

Little '77 KZ400 in the Big Apple

Black '99 RT for Everywhere Else, such as ...

[UberXY]

Chris: just for fun, get a fairly chunky piece of wire and run it directly from the negative terminal on the battery to a bolt on the engine case. This might help with your lights and turn signals. Sometimes on old bikes it just doesn't pay to assume that the engine is as well grounded as it would appear to be. Old cars, either.

[Rags]

Not specific to the issue, but I think this is great stuff for connections, bimetal contact or tough to get at splices..

 

 

http://home.comcast.net/%7Egregorbill/liquid.jpg

[ChrisNYC]

UberXY said Sometimes on old bikes it just doesn't pay to assume that the engine is as well grounded as it would appear to be.

 

I'd agree with that, Steve. I've actually been considering replacing the (very old and decrepit) oem ground cable with something a little more substantial ...

 

 

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Chris (aka Tender Vittles )

Little '77 KZ400 in the Big Apple

Black '99 RT for Everywhere Else, such as ...