Flat battery - why?

[psyguy]

UPDATE: YOU CAN GO DIRECTLY TO POST #107 FOR A SUMMARY OF THE PROBLEM. thanks



i started the engine multiple times during today's ride over a period of a few hours and a few hundred kms - and then all of a sudden i had a flat battery.
it happened once before (a few months ago, but i thought that was due to the battery being old, so i put a new battery in).




so:

• the battery is new and was on a charger til just before the ride
• the battery holds the charge overnight all right
• i recently tested the charging system and it was fine.
• most of the accessible electrical connections were cleaned and greased (other than those within the switches).

what do i do next?

[chef1366]

Recheck the charging system.

[errorcauser]

I'm sitting here trying to think of something, because I would figure you've got you're charging system in order, as chef mentioned and you mentioned.

Could it possibly be a shorted starter armature ? You start and start and start until the brushes land on the shorted section (like russian roulette), then press the start button...click dead battery ? If you're sure it's not the charging system, I'd swap out the starter for awhile and see what happens.

I don't know man, what I'm suggesting may be a silly ideal. But those windings can short out, I'd say. I'm just not sure what the result would be. <shrugs>

[posplayr]

to measure is to know. Get a VOM

[psyguy]

i'll re-check the charging system tomorrow, so i have a reliable information to start from.

[Steve]

Is your battery a wet-cell battery?

Have you checked the electrolyte level?

Constant charging of a wet-cell batter can lower the electrolyte level, leaving very little in reserve. If it has been dry for a while, there is not much chance of bringing it back up to snuff. If you have to change the battery, consider an AGM battery.

.

[psyguy]

latest data

battery is on a maintenance charger that charges the battery only when the voltage drops below certain level


today's readings:

• electrolyte level ok
• fresh off the charger battery reads 13.3V
• then it settles at 12.8V (ignition off)
• with the ignition ON: 12.5V across battery terminals
• honda rr with the sense wire spliced into the main orange wire going to the fuse block - voltage at that sense wire and battery neg 11.8V (i.e. 0.7V drop compared to the battery itself)
• charging voltage at 2000rpm 13.2V
• charging voltage at 5000rpm 14.4V

so, that's all ok, right?

[psyguy]

Could it possibly be a shorted starter armature ? You start and start and start until the brushes land on the shorted section (like russian roulette), then press the start button...click dead battery ?

would this cause the battery to immediately go flat? without any fuse going off?

[posplayr]

battery is on a maintenance charger that charges the battery only when the voltage drops below certain level



today's readings:

• electrolyte level ok
• fresh off the charger battery reads 13.3V
• then it settles at 12.8V (ignition off)
• with the ignition ON: 12.5V across battery terminals
• honda rr with the sense wire spliced into the main orange wire going to the fuse block - voltage at that sense wire and battery neg 11.8V (i.e. 0.7V drop compared to the battery itself)
• charging voltage at 2000rpm 13.2V
• charging voltage at 5000rpm 14.4V

so, that's all ok, right?

0.7V drop is high, but it seems to balance out to just about perfect charging at 14.4V

[posplayr]

would this cause the battery to immediately go flat? without any fuse going off?

battery can't just go dead without some smoke and flames. If you go key off 12.8V and 12.5V key on that is an indication battery is still good. Started could be open but the energy can not be either created or destroyed. All the charge in the battery cant just disappear.

The R/R sense wire is supposed to be switched. Some tell tales of pulling the battery down with the sense wire. Have you tried hooking it to something switched? I'm Too lazy to figure out is Orange wire is switched or not.

Pos

[psyguy]

0.7V drop is high

i assume this would be due to the coroded connections within the ignition switch (as this is the only switch on the thick orange wire), right?

is there any way of fixing this?

[errorcauser]

would this cause the battery to immediately go flat? without any fuse going off?

I'd imagine it could, but as you've brought up, it would probably blow a fuse. But, then again, anything's possible, I've seen some strange things before.

To be honest, I was grasping at straws in an attempt to try and help you, give you something to go with or check. I've seen your posts before, and I'm sure you know your way around one of these bikes. So, I figured you had the charging system in order, and not to much left to look for, you know ?

Steve, Bill, or Jim would be a lot better at helping you figure this out, I'm sure.

Like I said, my ideal with the starter may be silly. I'm sure they can short out, just not sure what one would do, or not do when it shorted.

[psyguy]

I'm Too lazy to figure out is Orange wire is switched or not.

Pos

the thick orange wire IS switched - it is the main wire coming back from the ignition

[psyguy]

To be honest, I was grasping at straws in an attempt to try and help you, give you something to go with or check. I've seen your posts before, and I'm sure you know your way around one of these bikes. So, I figured you had the charging system in order, and not to much left to look for, you know ?

thanks mate, i'm pulling my hair at the moment, as it unnerving to know you can loose your battery just like that - with no fried wires/fuses/etc.

[psyguy]

oh, btw, all connectors related to the charging system have been replaced with new ones and i have re-checked them today and nothing seemed loose
i was thinking i may have a loose connection somewhere so the charging system hooks off for a while, let the battery go empty during the ride, but this doesnt seem to be the case