what could cause my battery 2 run down after I've installed a new alternator and had the battery checked?

Question

My gszr1100 runs after the battery has been charged but after a while the lights get dim and my bike dies.

Answer 1

some people have already sort of answered this question previously there is some good advice but its a little bit complicated if you dont know much about electrics.
so i will try to simplify it.
get a multimeter a cheap one will do or borrow one,

To test is the bike is charging just set the multimeter to the dc voltage position (20 volts dc ) connect the red wire to positive on the battery and the black wire to negative, read the voltage without the engine running, then start the engine turn on the lights and measure the battery voltage again with the engine running at 3500rpm, if the voltage stays the same then its not charging, the reading on the meter should go to around 13.5 volts


if the above test finds it is charging you this shows both that the alternator is working and that the regulator is cutting the current off at 13.5 volts so you have either a bad battery which wont hold a charge, or the charge is leaking back through the rectifier (or possibly some other short circuit but i doubt it as if it was flattening the battery this quickly it should blow the fuse first)

to check if it is leaking back through the rectifier you will need to locate the earth from the rectifier and disconnect it from the chassis then connect the voltmeter to the earth on the rectifier to your frame if there is a reading without the engine running its faulty.

If connecting a voltmeter to the battery with the engine running (as described in first passage) finds that the voltage doesnt go up when the engine is running at 3500rpm then you have either a faulty regulator rectifier unit or a faulty alternator. on a conventional bike it is possible to check the alternator by connecting the voltmeter set to ac volts to the 3 white or yellow wires that lead to the rectifier and measuring the output set meter to 100v scale its often around 30 - 40 volts (however i see from one of the other answers that this bike has the rectifier built in to the alternator) This would mean that testing the alternator seperately could only be done if it was dismantled and the rectifier bit removed or disconnected (without seeing it i wouldnt know if it is possible to get at the ac wires)

so to sum up just connect the meter to the battery check voltage with and without engine running if no difference check all your wires.
well i tried to simplify it but its not easy it should take a competent mechanic no more than ten minutes to decide if your bike is charging or not, simply changing the battery would be the easy option to see if it is still the same borrow one from another bike as long as its the same voltage it wont damage your bike as it will only draw the current it needs, for example a car battery ccan be used to start a bike with no ill effect.
I would say its probably not charging or battery has had it.

Answer 2

--The alternator is just an AC generator. It generates alternating current of over 100 volts.
The charging system needs a way to turn AC voltage into DC volts - a "rectifier". Without a rectifier, AC voltage is useless in a DC electrical system. Your bike's battery needs DC voltage to charge it. If the rectifier is defective, then the battery will continue to discharge (go dead).
--Your bike also needs a "regulator". The regulator only allows approximately 15 volts of the massive amount of voltage put out by the alternator. Any excess voltage is sent to ground. If the regulator was defective, it might send all voltage to ground and the battery would get zero volts.
--Enough with the science class - if you haven't checked or changed the "regulator / rectifier", that could be your problem.
Another possible problem - if the battery has been discharged enough times, it won't have enough strength to "hold a charge". The battery should be checked with a "load tester" or "hydrometer".
--If you have a shop manual and multi-meter, you'll have the specifications, testing procedure and equipment to check your charging system. If you don't have the tools or knowledge, bring it to a shop for further diagnosis.

Answer 3

well in this bike the altenator and the retifier regulator are the same unit like an automotive style what you need to check first is called a key off drain hook up a multimeter in amps to the battery in series that means take off the negitive cable put the black test lead on the cabl and the red on the neg side of the battery and see how many amps is beign pulled with the key off it should be 0 unless the bike has an alarm if not thats what keeps draining the battery but u still need to make sure the batt charge wire is not broken or not connected

Answer 4

I had a mysterious power drain once on a Ford Taurus, and it was the alternator, but not in the way you are thinking. The alternator was charging well when the vehicle was running but the controller continued to bleed power through the field windings. Try disconnecting the wires that feed the field windings on your alternator when it's not running. Hook it up just before starting. If it's a one-wire disconnect the one wire. If it starts to work correctly that way then the alternator may need to be replaced.

Answer 5

I'm a little confused as to how somebody who doesn't know how to check a battery would try to install an alternator.

Answer 6

Something is still wrong with the alternator. You need someone to check that it is charging the battery with an Ammeter (Amp meter).

Something inline is open... you don't have a short, most likely... an "open."

Answer 7

It's called a direct short. check for shorts in the fuse box with a test lite and the ground wire {connect the test lite to the cable and probe the post if lite comes on there's a short pull fuses til it goes out that fuse will bee where you short is} note; key off during test

Answer 8

Do you still have a plastic plate or something similar to rest the battery on. Could also be a short, broken wire. The best thing to do is to test, test, test. Continuity...

Answer 9

You might have an electrical problem eating the battery. My car had that same problem and it ended up being my radio pulling the charge.

Answer 10

Did you have the voltage regulator checked out?