How do I know if I need a new alternator?

[ismatts]

Hello,

2001 600 Katana (Yellow)
Since I have owned my bike the last 3 years, the battery drain has always been an issue for me and i have to charge it alot. Last year I bought a new battery. The new battery was good for about 2 months and then the battery drain started happening again. I do not have any lights or LED light installed anywhere and nothing hooked upto the battery posts like aux lighter or something.

any ideas on how I can test this?

thanks

[Chilli99katana]

I recently figured out I needed a new alternator, because I was having the same problem...what I did to figure this out takes a little time, but it isn't that hard if you want to get it done yourself.
First, I took off the fairings and gas tank and airbox. Then I took a multimeter and disconnected the negative cable. Connect one lead of the multimeter to the negative cable, the other lead should be connected to the negative post on the battery. As long as you don't have something that is a constant power draw, (like a clock) then you should have a reading of zero.
I started to disconnect each electrical connection on the bike one by one. Started with the connections for the gauges and continued towards the back of the bike, ending with the tail light and rear signals. Make sure that you don't forget the ones under the air box. After that, I pulled the fuses one by one. I followed one wire to the alternator, and when I disconnected the alternator, the power draw went away.
Make sure that when you check each connection, reconnect it.
That's what I did, so Good Luck. I'm sure that someone can answer any ohter questions. I'm just learning myself.

[None2Slow]

Start the bike and put a volt meter on the battery. you should see somewhere around 13.2v. If its below 13, check all the connections from the alt to the battery and make sure there clean. If they are and its still below 13, then its time to start looking for a new 1.

[chemomche]

well man here in BG most of my friends jave charging problems
however,in most cases they are due to the regulator/rectifier relay that is a weak please for all suzukis, may checked it first before buying a new alternator

[The CyberPoet]

This might help:
CyberPoet's Katana (or general motorcycle) Electrical/Battery/Charging Systems Diagnostics & Repairs webpage

Meanwhile, my advice: buy a motorcycle-specific battery float/trickle charger (800 milliamp-hour charger with the ability to control the flow itself to shutdown to keep from overcharging), and leave it connected whenever you're parked. In the USA, I recommend the Deltran BatteryTender WaterProof 800 model

Cheers
=-= The CyberPoet

[ismatts]

Thanks for the input. this is the battery tender I have currently. Do you think this one is ok? or should I get a new one? it seems to work well, and does turn off when at full charge.

[STULER]

just from the symptoms you gave sounds like a alternator problem

[ismatts]

I will also pick up a multimeter. Man doing all this work myself is not only saving me money, but filling my toolbox rather quickly

[GytRDunKat]

It gets cheaper as you go, vs having a stealership do it for you

[The CyberPoet]

Thanks for the input. this is the battery tender I have currently. Do you think this one is ok? or should I get a new one? it seems to work well, and does turn off when at full charge.

In theory, charging with this 2-amp-hour/1.2-amp-hour/0-amp-hour charger can/does exceed the 98+ battery's ability to take a charge without damages. While it does have a float ability, it does not have a particularly low-output trickle setting, and it is designed for typical cars parked in storage (I've recommended/bought several of this particular model for friends' cars).
Is it responsible for lowering your battery-life? Possibly, esp. if you often have a heavily drained battery before you get around to hooking it up...

Question: Are you riding a California model?

Cheers
=-= The CyberPoet

[ismatts]

In theory, charging with this 2-amp-hour/1.2-amp-hour/0-amp-hour charger can/does exceed the 98+ battery's ability to take a charge without damages. While it does have a float ability, it does not have a particularly low-output trickle setting, and it is designed for typical cars parked in storage (I've recommended/bought several of this particular model for friends' cars).
Is it responsible for lowering your battery-life? Possibly, esp. if you often have a heavily drained battery before you get around to hooking it up...

Question: Are you riding a California model?

Cheers
=-= The CyberPoet

Ok, I will pick up a new one and stop using this one. I have used it on a pretty drained battery. I will also have the battery tested to see if it is bad. I do not think I have the california model. quick checks to tell, I will search.

thanks!

[GytRDunKat]

Question: Are you riding a California model?

I was just thinking the same thing.

[ismatts]

I was just thinking the same thing.

I am not with the bike right now, but I do know that the original dealer that this was purchased from was in Wisconsin. But I suppose that doesnt matter too much.

[The CyberPoet]

I do not think I have the california model. quick checks to tell, I will search.

California model has an electric fan on the left side of the engine, designed to run after the engine shuts down for a certain amount of time to blow cool air across the carbs (preventing the fuel in the carbs from boiling/evaporating as readily -- a pollution control system as it were). The fan running anywhere from 5 to 60 minutes after each use of the bike tends to suck a lot of juice from the battery.
Disconnecting that fan resolves that massive drain source, and does not change the operating nature of the motorcycle.

Cheers
=-= The CyberPoet

[ismatts]

I do not think I have a fan on the bike. but I will double check for sure when I get home.