How many miles to recharge battery after starting the engine?

FatBob

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If I ride 30 miles to work while running the headlight, BMW spot lights, heated grips on low and an autocom, will the ride be enough to recover the charge used to start the bike in the first place?

What if I also run a heated jacket (the DIY one other people have posted about) which draws about 5A i think - can't be much more than that because it runs from the aux socket under the seat which I think has a 5A limit?

Juts wondering if all the winter gadgets are going to kill the battery and leave me stranded at work!
 
Don't know the answer exactly but advice elsewhere was to switch off aux lights and grips a mile or so before arrival to give a chance for some charge to go back into battery.
 
FatBob said:
If I ride 30 miles to work while running the headlight, BMW spot lights, heated grips on low and an autocom, will the ride be enough to recover the charge used to start the bike in the first place?

What if I also run a heated jacket (the DIY one other people have posted about) which draws about 5A i think - can't be much more than that because it runs from the aux socket under the seat which I think has a 5A limit?

Juts wondering if all the winter gadgets are going to kill the battery and leave me stranded at work!
Click to expand...

Depends. Why not buy a battery charger and never have to worry?
 
My guess is that it'll be ok as long as you don't use the heated jacket. But I'd follow the suggestion of charging the battery up overnight to make sure it starts easily and on the first push of the button. 1200's aren't exactly renowned for having large capacity batteries and alternators.

One way to help would be to use a battery powered heated jacket, like the Keis etc ones. Then you can be warm and have a bike that charges its battery :)
 
should do that easy IMO.

the 1200 has a pretty good alternator, especially the GSA and later GSs.
 
Lights 60/55w main + low
grips 4amps = 48w

spot lights 2* 35w

other lights 21w stop 5w tail instruments 5w

engine (not sure) but at guess 50w maybe 100w

so total = 60+55+48+70+21+5+100 = 359watts

Alternator = 720watts

may have missed quite a few out but plenty of spare capacity.

The GS / GSA seems to have one of the largest alternators of any bike I know
 
FatBob said:
If I ride 30 miles to work ...
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There are too many variables to give anything like an accurate answer.

Duration and revs are bigger factors than miles. But so is weather; time spent at a red light; health of your battery; tightness of the alternator belt; how much you use the winkers; what you had for breakfast etc etc.

Greg
 
i don't know for certain, but i'd expect the battery to be charging at tickover, or just over anyway.

it's not an airhead.
 
cookie said:
i don't know for certain, but i'd expect the battery to be charging at tickover, or just over anyway.

it's not an airhead.
Click to expand...

At tickover the alternator would be 'putting out' so to speak, but probably wouldn't cover the load on bare running (eg ignition, fuel pump and headlight). The battery would be taking up the slack during the idle period.

Greg
 
Greg Masters said:
At tickover the alternator would be 'putting out' so to speak, but probably wouldn't cover the load on bare running (eg ignition, fuel pump and headlight). The battery would be taking up the slack during the idle period.

Greg
Click to expand...


i'd be interested to know.

i may get the multimeter out tomorrow.
 
Greg Masters said:
At tickover the alternator would be 'putting out' so to speak, but probably wouldn't cover the load on bare running (eg ignition, fuel pump and headlight). The battery would be taking up the slack during the idle period.

Greg
Click to expand...

you sure about that? certainly true in the old days with a dynamo. I thought if the dash 'charge' light was out, then there was not a drain on battery.


you could always do a little test on your drive. turn everything on and measure the voltage. More than err um 12.6v (??) and you are charging.
 
Greg Masters said:
At tickover the alternator would be 'putting out' so to speak, but probably wouldn't cover the load on bare running (eg ignition, fuel pump and headlight). The battery would be taking up the slack during the idle period.

Greg
Click to expand...

I think it will cover these items at idle but not much else.
 
FatBob said:
If I ride 30 miles to work while running the headlight, BMW spot lights, heated grips on low and an autocom, will the ride be enough to recover the charge used to start the bike in the first place?

What if I also run a heated jacket (the DIY one other people have posted about) which draws about 5A i think - can't be much more than that because it runs from the aux socket under the seat which I think has a 5A limit?

Juts wondering if all the winter gadgets are going to kill the battery and leave me stranded at work!
Click to expand...

it all depends on the condition of the battery?


Hman
 
Does the bike have servo brakes. If so do you keep the brakes on whilst at junctions to ensure the brake light is illuminated?

Could be the straw etc.
 
John Armstrong said:
I think it's a voltage difference detector, ie generator producing more volts than battery = light off and light on if the battery is at a higher voltage.
Click to expand...

That's right. As soon as the voltage from the alternator matched the battery voltage, the light goes out. But in that state there is neither discharge nor charge of the battery.

:thumb

Greg
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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