Flat Battery on my bike

[chunkolini]

The bike is a 25 year old Honda Africa twin.
When I got it the battery would not hold a charge so I replaced it.
That was a couple of months and a few thousand miles ago. I have not used it for about four days, I came to start it today and click goes the starter solenoid.
The only thing that can be draining the battery is a tiny LED light in my 12v charger for phone etc that is plumbed into the battery directly. Might this cause enough drain to flatten the battery?
Since fitting the battery it has started on the button, no struggling or any of that nonsense.
Might it be the dreaded dead regulator?

 

[wristpin]

Know nothing about bikes but a bit about ride-on lawn mowers! Does it have a diode or something to stop the battery discharging back through the alternator?

 

[roofman]

The bike is a 25 year old Honda Africa twin.
When I got it the battery would not hold a charge so I replaced it.
That was a couple of months and a few thousand miles ago. I have not used it for about four days, I came to start it today and click goes the starter solenoid.
The only thing that can be draining the battery is a tiny LED light in my 12v charger for phone etc that is plumbed into the battery directly. Might this cause enough drain to flatten the battery?
Since fitting the battery it has started on the button, no struggling or any of that nonsense.
Might it be the dreaded dead regulator?

silly question but are you 100% sure the batt is dead...could be a starter playing up otherwise

 

[DanielW]

It would take a few weeks/months for the led to drain the battery providing the bikes not used.

I suspect something else? is draining the battery unless the battery is duff to begin with despite it being new? maybe the reg is not charging the battery when bike is in use? or the stator windings are not delivering a current to the reg?

 

[pedrobedro]

The only way to check it is to start it with a jump battery then check if it's charging with a meter. Across the terminals it should give about 14.8v if the regulator rectifier is working properly.

 

[barracuda816]

After that check the drain with multimeter (on milli amp range) in series with the battery. The LED wont drain it that quickly but the charger may still draw current, worth a 20 min check.

 

[chunkolini]

I will have a look at the solenoid in the morning.
I have been piling on the miles lately, this is the longest it has sat since I have bought it, and it is ancient. Then I will attempt to measure the voltage across the terminals.
I doubt it is the regulator has it has been starting first flick of the button everytime. Duff reg would not charge the battery??

 

[chunkolini]

It must be the battery, Turn the ignition on, lights are feeble, add indicators and they glow pathetically.
Typical my battery charger has a blown fuse, I will change that am, put it on charge and see if I can get my head around my cheapo meter.

 

[outofthefire]

Do you think its karma for all the bad things you've done to folks bicycles in the name of sport good luck I hate bike electrics

 

[mike os]

right sort of age for faulty reg/altenator.....

 

[mike 109444]

It must be the battery, Turn the ignition on, lights are feeble, add indicators and they glow pathetically.
Typical my battery charger has a blown fuse, I will change that am, put it on charge and see if I can get my head around my cheapo meter.

Post a pic of your meter and plenty on here will advise what setting for what test.

 

[mike 109444]

Your phone is not a period one to match the age of the bike is it ?

 

[dobbslc]

right sort of age for faulty reg/altenator.....

Plus its a honda....
Seriously a duff reg rec could drain the battery, try testing with a meter set on the 10amp range. Disconnect the positive lead from the battery then put the leads between the battery terminal and the disconnect lead, this will give you the currant draw on the battery.
DON'T touch the starter button or you'll bugger the meter!
If you see a currant drain then pull out the fuses one by one to see what stops the drain. If that doesn't stop it try pulling apart the block connectors to various parts of the bike like the reg rec until you see the currant drain stop.
It could be a bit of knackered insulation somewhere on an old bike like that.
Also might be worth checking for the dreaded Honda "earth block fungus"
Quite a few Honda's have a big sealed earth connector block hidden under the side panels that corroded and causes all sorts of problems, it's used at the factory as a test point then sealed up with tape the only thing is it gets wet eventually.
Rob

 

[brightspark]

well the 1st thing id do is charge the battery. put it back on the bike and check it with a battery tester . if its ok start the engine and it should show about 14 volts if the alternator is charging . if all ok take one lead of battery and stroke it across the terminal if it sparks u are using power and it needs investigating where the loss is

 

[chunkolini]

I have avoided going over the wiring loom.
it has all worked so far. I have spotted a few random unconnected wires, the cooling fan is turned on via the kill switch. etc etc.
So connect a charged battery, and check the voltage across the battery terminals when the motor is running?
I will try and fine my five quid meter and get a photo of it. Typically everything I own is packed for moving soon.

 

[Shox Dr]

AT are known for frying Rectifiers. One with the correct round plug are 120quid plus. All you need is a 5wire, and mod the connectors, they can be picked up on the net for 25-30quid.

And buy an optimate or similar, and use it.

 

[chunkolini]

Yep!
And maybe a soldering iron and learn how to use it.
Trouble is I am mid house move and need to be mobile. May have to go SH for now.

 

[chunkolini]

Mr Fuzzy, nice link. So many connectors and so many prices. I reckon go mid range and take a punt on it.
I will investigate further.
it is shocking that this is still the traditional thing to go wrong on bikes even on 21st century bikes.
Edit, there is one on there for forty five quid that looks to fit.
If I need one that will do for now.

 

[voipio]

The phone charger current drain will be more than just the LED, as the regulator circuit will also draw current. I have a 12V to 5V fairly low current phone charger that consumes 20mA on standby. It doesn't seem much, but multiply that by 4 days (96 hours) gives 1920mAh. That's a fair chunk of the battery's capacity, and certainly enough to take the edge off the battery's engine starting performance. If the charger draws any more than that, then the loss of capacity will be correspondingly greater. Add to that any of the additional problems mentioned by the other posters. It's also worth checking the battery's terminal voltage whilst the engine is running, headlights off, after having had the bike out on a run of a few miles. It should be around 13.8-14.4V. Anything outside that range will be a clue. Using headlights when riding could contribute. They could be quite a drain, especially if there's a lot of low rev motoring, such as stopping and starting in traffic.

.

 

[pedrobedro]

If you need to charge a phone fit a cigarette lighter type accessory point and plug a USB charger in it and take it back out when you've finished. A 10amp inline fuse is a good idea, you could fit a fuse in your present charger and take it out to kill it when you are not using it. but it's a lot of fiddling if it's under the seat.