Battery keeps draining

[godminus]

Hi!

FZ6 2005, battery rather new. I drive DAILY from home to work, and about two days a week out of town, about 60 miles each day.

I'm on a vicious cycle: each tuesday, before I go out of town, the battery appears to be almost DEAD. Starter spins slowly, bike refuses to start, and eventually after 2 tries, bike is DEAD.

After I drive those 60 miles each day for two days - battery is like new - so charging is super fine I guess.

but then again, by the time I reach tuesday again - each day I can actually feel it battery is weaker, getting weaker and weaker every day!!

I have no alarm on my bike.

What can cause such a drainage??
Maybe bad battery?

 

[Humperdinkel]

I'm not real good at explaining electrical systems but I'm sure Motogiro will be along soon enough & he is a guru

It could be a bad battery but my guess is a regulator/rectifier :thumbup:... Providing there are no other sources of drainage, ie a GPS ??

 

[godminus]

No other power consumers whatsoever! no alarm, no gps, nothing!

As I mentioned before: charging is fine! when after the battery drained out completely, a 60 mile trip recharges it just fine (starter sounds healthy and spins fast)

 

[Solarservant]

I work with batteries frequently, and have come to learn their idiosyncrasies. I also dealt with the same issue back in my scooter days.

I'd say first off, your charging system is fooling you. If your battery is already in a weakened state (which it is, right? You say it's been absolutely dead a few times now.) It won't take much of a charge for that battery to "spring back" to what looks like a full state of charge. You will go a few days with enough juice to crank the engine and then you're back to nothing.

Check out your charging system. I agree with the earlier post. You've got a bad voltage regulator/rectifier. Not sure what the FZ has, but it's probably an easy swap with an OEM part.

Then, replace that battery. It's toast. Once you've lowered the voltage to "dead," it will never be able to be charged completely again, and you'll just continue to be frustrated by it.

Good luck!

 

[godminus]

The mechanic over the garage tested the charging system several times and he said it's perfectly fine, he also checked the electrical coils and everything looks fine!

 

[FIZZER6]

Sounds like the battery is shot. I agree with the earlier poster, once a battery goes completely dead a time or 2 it's toast and will never hold a full charge again.

I had a similar issue with my lawn tractor battery last week, it would start fine if I had run it in the last day but wait a week and the battery was fully dead. Thought maybe it was the charging system but it ended up being the battery. Batteries on motorcycles don't usually last as long as daily driven car batteries unless you store them in climate control and run a trickle charger when not using them for a week or more.

 

[Motogiro]

Load testing the battery is the best way to see if the battery has "depth of charge" Some new batteries depending on technology will need time on a charger before it is put into service. If this is not done the new battery can experience poor performance and early failure. Make sure the new battery is fully charged!
Fully charge your present battery and have it load tested. This does not negate the fact that you may have a problem with the charging system and hence have a leaky diode that allows the system to drain or is not rectifying power that is needed at the proper rate. Too often we get the voltmeter out and voltage is not the only reading that tells us what rate or current the charging system is providing or capable of. Voltage measurement is a fairly good way to ascertain the charging system is good but there other factors that should be considered for a healthy charging system.

I agree if a volt meter shows good voltage 13.5-14 vdc at 2000 rpm your charging system is probably fine and a new battery may be the cure. If you experience the same failure after the new battery, the system needs to be leak tested to find out if there is a drain on the battery.

 

[godminus]

I asked the mechanic if it's possible there's a leak in the system (i.e when the bike is not running, something is draining the battery) and he said no

Anyhow the battery is still on warranty so hopefully they'll replace it free of charge...

I guess this is the best option I currently have as the charging system was already tested...

 

[Solarservant]

Man, sounds like you are dealing with a real hassle here.

At the very least, when you replace the battery, you'll find out if something is wrong with the charging. Wanted to say that I agree with Motogiro 100% about only checking voltage out of the system. That can be misleading also.

Don't forget that problems that are rooted in a short love to act intermittently, making them that much harder to diagnose.

 

[regder]

Just cause the battery is recent does not guarantee that it's good, I've seen many batteries fail shortly after install.

In the mean time, you can check the current draw. Perhaps something is staying on when it should be turning off, draining the battery.

 

[lkea]

I would suggest to have a battery load test to check the battery state and charging unit. It could be the rectifier or the stator it self that is the culprit.

 

[FinalImpact]

What are you charging it with? Trickle charging is OK to maintain a full battery, but restoring a depleted battery should come from something cable of matching the ten amp hour rating. Slowly charging doesn't create enough chemical change inside the battery to stop the internal resistance from draining itself.

Battery Spec:
Model GT12B-4
Voltage, capacity 12 V, 10.0 Ah
Specific gravity 1.320
Manufacturer GYM
Ten hour rate amperage 1.00 A

Upstream someone mentioned testing for drain. With a volt meter and a 1 ohm resistor, you can calculate system drain. If you have DMM capable of directly measuring current of an Amp or so, place it in between the one of the battery leads. You should see no current. Like less than 0.005 Amps.
Something as small as 25mA (0.025A) will drain a battery in 7 days.

If you want to check this and need more details on how to verify drain, ask and someone will chime in.

As for battery life; my bike has the original battery from 2008-01. Bike was manufactured in 2008-06. It has never been on a charger since I took ownership in early 2011 and it sits for FOUR MONTHS in winter with no charger but one lead disconnected. It has started just fine every time.

When I park it; its 12.99v. When I went to start it, 12.96v. Very little internal resistance as the battery is not killing itself. Its plates are not sulfated, and its fully charged all on it's own. There is no need to trickle charge.

 

[oaks]

The first post is similar to how my battery failed a couple months ago. It finally got to where it didn't hold enough of a charge to start the bike after it sat overnight.

The battery was the original Yuasa GT12B4-GS, only about 2.5 years old, and I kept it on a maintainer if it sat more than a few weeks. I don't know why it wore out so quickly.

I replaced it with a Yuasa YT12B-BS, about USD 100 at a local shop, and charged it fully with a maintainer before first use. (The shop owner said that would extend the life of the battery.) No problems since.