Battery problems any suggestions?

[Thunder]

Ok bit of a mystery so time to pick the collective brains for some ideas.

Went out to take the bike out for a run on Wednesday but when I went to start it not enough power from the battery, click click from the solenoid and the clock reset indicating a drained battery.

"Oh deary deary me" says I only not in those exact words cause only 6 weeks ago I replaced the stock battery with a lovely new Odessey Gel battery to provide more get up and go went I wanted to get up and begone!

As I still wanted to get out I popped the tank off and refitted the original battery (which had not been faulty it has to be said) but it lacked enough power to get the bike going having been sitting dormant.

Resigning myself that the 1150 GSA was going no where I took the 100 PD for a run instead and left the 1150 with an Optimate plugged into an accessory socket to charge the battery overnight.

Thursday morning dawned bright and clear with the Optimate showing a green fully charged reading. "Excellent" says I, unplugged the Optimate and went to start the bike. Started churned for a second then the clock reset and all indications of a dead battery. " Deary, deary me" says I "What a palaver! Now what?"

Now what was the connection of an auxiliary power pack to the external jump start connections of the GSA and another try, a clean of the main plugs and the bike fired first push of the button.

Took it out for a run, sweet as a nut then back to base. Left the bike for 10 minutes while making a cuppa, went back hit the starter and the dreaded churning again. Fitted the external power pack, button, brum, brum.

Repeated the exercise a number of times and it's the same story, no sign of the red charging light when running, connecting the Optimate throguh either the accessory socket or the external jump points and within 5 minutes it shows a green light for a fully charged battery, checked the voltage of the battery and it's 13 volts so what's the problem?

Totally stumped, any ideas? Dodgy starter motor requiring additional voltage?

Any thoughts?

 

[wilbjr21]

It would appear that you have a high resistance connection (or lead) between the battery and the starter motor.

This part of the starting circuit won't be used with your "emergency connection" and thus the bike starts OK from your starting device.

 

[Thunder]

It would appear that you have a high resistance connection (or lead) between the battery and the starter motor.

This part of the starting circuit won't be used with your "emergency connection" and thus the bike starts OK from your starting device.

Thanks for the input?

Any suggestions how to identify such a connection or how it may have happened?

 

[wilbjr21]

The usual thing would be dirty (or slack) connections - althought this would be unusual on one of your bikes (I've seen the pictures).

It would be the best place start though......... the technical way would be to try and measure the volts drop across the connections when trying to start - a high resistance will drop more volts.

 

[Thunder]

Thanks for that, I'll pull the tank off when I get back on Sunday and have a look.

Keep em coming chaps

 

[DollyRocket]

If you measure the voltage from a good earth point and the jump start terminal (which should be directly connected to the starter solenoid) when you turn over the engine the voltage shouldn't drop too much from quiescent. If it is below 11V from a fully charged battery then the starter is probably pulling more current than is available. Batteries are also quite dependant on temperature, changes of about 20C can influence the capacity of a battery by 50%

Lead acid cells should have a cell voltage of about 2.1V per cell {6 cells in a 12V array) = 12.6V when fully charged but rested. This should drop to no less than 10.5V upon load (if it does there is either a high resistance path or the battery capacity is not sufficient to supply the current).

The main bulk charge should take the battery voltage 14.4V with float charge sitting around 13.8V. If it goes to trickle in 5 mins it would suggest that the capacity is next to nothing! When you changed the battery did you make sure the leads were clean and uncorroded, when you dismantle the terminals you may have got grease or water in between the lead and battery post, this is a sure fire way to give you a high resistance path. (also explain the short charging time since hardly any power was actually drawn).

To make perfectly sure, take the battery off the bike and charge it on a bench and see how long it takes to charge - it may be worth to also measure the start, float and end voltages over time to see if it is 'taking charge'.

I have just bought one of the new oximiser chargers with a current read out, this way you can determine a lot more about the state of the battery based on the current it draws on charge and on float (trickle).

Sorry to be a bore, but I spend all day every day trying to perfect the chemistry of batteries

 

[ELIMINATOR]

http://www.yuasa-battery.co.uk/automotive/technical.asp#allyouneedtoknow

May be of some use.