Get Home with Failed Battery.

[magg]

A suggestion if ever caught out by a failed battery. By failed battery I mean, you have stopped for lunch on your weekend ride and when you return to your bike and press the starter button the engine fails to crank and the instrument panel lamps go dim.

First option is to attempt to push start the bike. If it starts and idles but dies when you try to rev it, try switching on your headlights and/or the stop lights. The additional electrical load could improve the engine performance, but do not expect a miracle, just a bike that runs to maybe 5000rpm and will get you home.

Second option if the bike will not push start is a bit more complicated but worth a try to avoid a tow etc. You need to disconnect the battery (that's the complication) and try push starting again. If successful, reconnect the battery while the engine is running and then add electrical load as needed to extend the rpm range of the engine.

[amorti]

A suggestion if ever caught out by a failed battery. By failed battery I mean, you have stopped for lunch on your weekend ride and when you return to your bike and press the starter button the engine fails to crank and the instrument panel lamps go dim.

First option is to attempt to push start the bike. If it starts and idles but dies when you try to rev it, try switching on your headlights and/or the stop lights. The additional electrical load could improve the engine performance, but do not expect a miracle, just a bike that runs to maybe 5000rpm and will get you home.

Second option if the bike will not push start is a bit more complicated but worth a try to avoid a tow etc. You need to disconnect the battery (that's the complication) and try push starting again. If successful, reconnect the battery while the engine is running and then add electrical load as needed to extend the rpm range of the engine.

Bad advice.

If the battery has failed while you are riding, there are very strong odds it is because the regulator has cooked it, or because the regulator* has failed and the battery is not being charged. If the former, then riding the bike any further will mean continuing riding at 19v, which may blow your dash bulbs, then headlight bulb, then CDI. If the latter, then you will get 0v and you are only going to get a few more metres until the bike stops again.

The only "get you home" method is if you are really lucky and happen to be riding with a mate who has a compatible battery and a healthy bike. If you are, then swap batteries over, and unplug your regulator. He has to bump start his bike, but due to the healthy charging system he will be able to make it home on the power from the alternator. The battery if dead becomes just a big capacitor, if you are lucky it might even charge a little. You should push start your bike, ride with lights off. Typically you can get at least 40-50 miles on the electricity stored in the battery when it's just powering minimal lights (brake and signal) and ignition.

The only reason you might be right is if the battery has failed, which is to say the entire charging system is healthy and giving sensible voltage, but the battery has just died of old age anyway. This is, IMHO, unlikely. Reason being, they will almost invariably fail in winter, and by the method of just not starting in the morning when it's been cold over night.

Quite apart from that, I would love to see you try and start a bike with no battery in it, never mind keep that bike running long enough to get the battery back in Here's my advice - keep your guesses for yourself.

*or alternator or other part of charging system

[magg]

Not a guess, it works as I used it to get home myself. Batteries do die without a failed rect/reg as the cause and do not always wait for a cold morning in the garage and you may not have a mate with you to share a good battery.

If the reg has failed then the over-voltage issue is accommodated by the added electrical load of headlight once the engine is started. Even a good rect/reg will need the added electrical load to consume some of the charging system output, to stop the reg pulling the output below 12 volts. Yes the charging system has enough power to run the ignition system during a push start.

The decision to try my suggestion is up to each individual but with the choice between being stranded on a isolated country road and attempting to get to somewhere better, I took the latter.

[Neosophist]

Not a guess, it works as I used it to get home myself. Batteries do die without a failed rect/reg as the cause and do not always wait for a cold morning in the garage and you may not have a mate with you to share a good battery.

If the reg has failed then the over-voltage issue is accommodated by the added electrical load of headlight once the engine is started. Even a good rect/reg will need the added electrical load to consume some of the charging system output, to stop the reg pulling the output below 12 volts. Yes the charging system has enough power to run the ignition system during a push start.

The decision to try my suggestion is up to each individual but with the choice between being stranded on a isolated country road and attempting to get to somewhere better, I took the latter.

I have to go with amorti on this one, he's spot on.

Unless you have a multi-meter with you to diagnose charging problem then NEVER ever run a bike, let alone ride it with a suspected charging problem.

If it's over-charging you can boil away all the acid.. on a wet cell this will leak out and if you dont' have a vent tube it'll go all over the frame and eat away everything.

If you have a sealed battery it will leak too and you probably don't have a vent tube so it'll go everywhere.

Worst of all the battery can catch fire / explode (i've seen this happen! - not a pretty site)

If the reg has failed then the over-voltage issue is accommodated by the added electrical load of headlight once the engine is started.

I'm sorry but this is pure-gues work / speculation / wrong.

This isn't how electrics work... the headlights won't balance things out.. they will consume some amps and may stop the battery over-chraging if the genny is putting out low amps.

Voltage is another issue.. the headlights are 12v.. they'll work upto about 16v give or take.

The genny puts out at least 50v AC at 5000rpm.. 50v is going to kill the ECU / headlights among other things..

Best advice is what amorti said. if your with a friend and you can fit their battery then do so. Unplug genny and reg-rec and ride without lights.. this will get you quite far.

I keep a small multimeter under the pillion seat to check for such things (as well have having an ammeter on my NC24 )

Do not guess the charging system, you can go from bike dying to destroying most things by keeping on riding.
Their charging system will charge your old battery if it's not goosed or it'll just act as a capacitor and smooth things provided it isn't totally fubared.

[magg]

I could take issue with the reasoning behind the concerns expressed about my "get home" suggestion but as it was my intention only to assist anyone caught in this situation, I will let the matter rest. Further discussion would become technical without benefit to anyone, although I would suggest a voltmeter, instead of an ammeter, is the best method to detect overcharging of the battery.

[Matchlessman]

Breakdown cover and a phone?

[amorti]

I could take issue with the reasoning behind the concerns expressed about my "get home" suggestion but as it was my intention only to assist anyone caught in this situation, I will let the matter rest. Further discussion would become technical without benefit to anyone, although I would suggest a voltmeter, instead of an ammeter, is the best method to detect overcharging of the battery.

I see what you are trying to do, but what your tip really would do, would be catch out those that don't know better, who then don't get much further, but their bike is in much worse condition than it could've been saved at.

[Neosophist]

I could take issue with the reasoning behind the concerns expressed about my "get home" suggestion but as it was my intention only to assist anyone caught in this situation, I will let the matter rest. Further discussion would become technical without benefit to anyone, although I would suggest a voltmeter, instead of an ammeter, is the best method to detect overcharging of the battery.

I see what you are trying to do, but what your tip really would do, would be catch out those that don't know better, who then don't get much further, but their bike is in much worse condition than it could've been saved at.

Exactly this.

It's good to help people but sometimes, even the best intentions can have really bad consequences... plus you have learned something now?

While your plan of action got you home it isn't the best thing to do... doing it in the same circumstances but with the reg-rec gone the other way, as often happens and could happen to somebody heeding this advice and you risk much more serious damage.

Please don't take it personal the fact i'm going to correct you twice, as I really do like your sentiment of trying to help others but a correctly installed ammeter really is the best way to see if your bike is charging or discharging.

Ammeters provide a real-time view of charge / discharge... the one in my NC24 has -12 0 +12 (discharge / charge in amps)

A voltmeter can be considered 'stale' it is only useful if your reg/rec decides to seriously over-volt and you get a huge spike... (if the excess juice doesn't blow your fuses / dials in which case you'll know anyway!) It isn't so useful in detetcing a drop in charge.. especially if it's only subtle.. the difference between charge and discharge in voltage terms is minor. And if you have a gradual drop in charge rate, such as a dying battery, you'll notice it a long time before it takes out the reg-rec.

In your case where everything was ok but it just died you'd clock it with an ammeter straight away.

Have a read of this website, hopefully it'll clarify how an ammeter works.

http://www.motorcycleproject.com/motorc ... meter.html

While i'm feeling all philosophical about things.

I think it's better to have tried and failed a 1000 times and learned something each time than to succeed once without learning a thing.

Peace out.

[magg]

Lets say we agree to disagree.

[Cammo]

Off track a bit, but check out what the faulty charging system did to my cdi:



That wasn't actually the worst of the damage - the cdi casing had caught fire. Not a nice sight when you have a single seat unit fitted and no tools on you!

I pretty quickly got the seat unit off using the ignition key...