Driving Lights Drain My Battery

[RevRoy]

I just installed a pair of halogen driving lights on my '80 GS550E. Everything was fine Friday as I rode it to and from work. Today, I ran several errands, which involved several stops. After the fourth stop, my engine died at a red light (which never happens) and it would not start. It turned over slow because the battery was low. I pushed it off the street, gave it 10 minutes, and it started.

I rode it home, about four miles, and the engine died in my driveway as I waited for the remote-garage door to open. The bike would not start or even turn over. I jump-started it off my car. The rest of the day, I did not turn on the new lights and the engine started every time and the bike performed as normal. Ergo, the new lights are overpowering my charging system.

My battery is six weeks old, so I know it is not that. Anyone have any ideas on how to get my alternator/battery to handle the extra amps? I really enjoy the lights, especially at night, but if they drain my battery what I like really does not matter.

Thanks.

 

[Grandpa]

You have two choices:

1. Remove the driving lights, and face the fact that your ancient GS was not designed to take the added load when it was new, let alone when it's a quarter-century old.

2. Get yourself a Gold Wing or a modern sports tourer with the alternator capacity.

Installing driving lights on a GS is a bad idea. Period.

 

[RevRoy]

I was afraid you'd say that.

 

[earlfor]

Driving lights are usually about 55 watts each. The stator
/alternator does not have sufficient output to run those lights.
Stator output is about 240 watts. The bike consumes 160 watts normally with the stock headlight off. The stock headlight consumes 55 watts, so your average/normal consumption is around 215 watts which leaves 25 watts to charge the battery. Forget the added driving lights. You can replace your stock headlight bulb with an Isram Silverstar which draws the same power as a stock bulb but increases light output over stock by about 50%.

Earl

 

[earlfor]

Or, you can buy a Bandit12 which has a 50 amp, variable output, automotive type alternator.

Earl

You have two choices:

1. Remove the driving lights, and face the fact that your ancient GS was not designed to take the added load when it was new, let alone when it's a quarter-century old.

2. Get yourself a Gold Wing or a modern sports tourer with the alternator capacity.

Installing driving lights on a GS is a bad idea. Period.

 

[RevRoy]

I'll check into the headlight. I bought a "halogen" headlight from Advance Auto, but I have figured out that the pattern is much different for bikes. Thanks for the suggestion, Earlfor. The driving lights are sweet, but I think I'll put them on my '78 Thunderbird (rust-free, no-door dings -- God help the person responsible for the first one -- 62,000 miles ... as new).

 

[Steve]

Or, you can buy a Bandit12 which has a 50 amp, variable output, automotive type alternator.

Earl

Really? That's more than a stock GoldWing alternator.

Fortunately, the previous owner of my Wing saw fit to replace the original with a 90 amp unit. \\/

.

 

[Matchless]

I have heard that rewiring the stator (to slightly higher specs -more copper) and replacing the regulator (beefier one) can give some improvement on the maximum wattage or current available. Some GS alternators are rated for 18A which translates to 216 watts, where two riding lights will add 110 watts @ 55w each, meaning you need additional alternator output capacity of at least 9-10 amps.
Maybe someone else on the forum knows the maximum that can be gained in this way.

earlfor, thanks for the tip on the Osram Silverstar lamps I see they say:
"Exceptional specifications
Thanks to their special technology OSRAM SILVERSTAR lamps illuminate the road with an up to 50% brighter light in the crucial zone 50 to 75 m in front of the vehicle than a corresponding standard halogen lamp (depending on the headlight). The fact that the cone of light is up to 20 metres longer offers even greater safety. Obstacles and other dangers can be seen sooner and better, as can road signs and markings."

 

[Grandpa]

Or, you can buy a Bandit12 which has a 50 amp, variable output, automotive type alternator.

Earl

That would be a smart thing to do, Earl!

 

[Steve]

You can replace your stock headlight bulb with an Isram Silverstar which draws the same power as a stock bulb but increases light output over stock by about 50%.

Please note that this is the Osram Silverstar, not the Sylvania Silverstar bulbs you find in the auto parts stores.

The Silverstar bulbs that Sylvania sells have a blue coating on the bulbs to make them look like expensive HID bulbs. Looks just don't cut it when trying to produce light. The Osram bulbs are built to European specs which prohibit the blue coating, which gives a better light. The Osram bulbs are frequently available on eBay. You are looking for H4 bulbs for your bike.


.

 

[tomm]

I added a PIAA 004X lamp kit (Dennis Kirk: 21-1010) to my 78 GS750E at the beginning of this year and have not had any problems. 60 watts of output out of 35 watts of power. I only use them on roads where I can generally keep the revs at 4K or better, and suspect I might have a problem if I used them around town, but they work great work the way I use them and they add a lot of light. I do not shut them off at traffic lights and short stops. Primarily have them because of the prevalence of moose and deer around where I live and ride.
I have the stock stator, but the Electrosport R&R replacement. I have also replaced much of the bike's critical wiring, and added additional grounding.