How do I check the charging circuit?

I got some really useful information when I posted this (http://forums.sv650.org/viewtopic.php?t=49216) yesterday. It looks like I may need a new battery but as suggested in the replies I thought it might be worth checking my charging circuit before I part with my money.
Does anyone know how to check this?

I can check that the batery is sittting at or around 12v but surely this doesn't prove that it has charged properly. Do I not need to check the current supplied by the charging circuit?

Any ideas?
Chris

[Sid Squid]

Originally Posted by I Previously

First charge the battery and check the voltage across the battery terminals, (not immediately after disconnecting the charger, you'll get a falsely high reading), should be about 13V, much less and the battery is past it's best, do this first as some supposed charging system faults are duff batteries.

With the lights on and the engine spinning at 5000rpm there should be a reading of between 13.5 and 15V at the battery, if the reading is above 15V the regulator doesn't, if it's below 13.5V either the regulator is toasted or the alternator or wiring is goosed. This is a good rule of thumb test, but does assume that your meter is reasonably accurate, if you're not convinced your meter is accurate try this:
Ensure the battery is fully charged, start the engine, turn on the lights and rev the motor to about 5000rpm, what you're looking for is a rise in the reading of at least a volt, and when the engine speed falls back to tickover that it's still either equal to or preferably a bit above whatever reading you got from the battery alone.

i told u in ur last thred

[Viney]

And hes been told in this one. Now let that be the last of it

Originally Posted by Sid Squid

if the battery is only half charged, will you get a reading of 6.5V ?

im not fooling around, just trying to get my head around voltage, amps, watts, and multi meters and stuff.

No, if you ever get that it's completely flat or has a dead cell.

Read this http://en.wikipedia.org/wiki/Ohm's_law

and this http://auto.howstuffworks.com/question324.htm

and this too http://en.wikipedia.org/wiki/Lead-acid_batteries

Originally Posted by Sid Squid

so why have i got to wait until the battery is fully charged before i carry out this test ?

and approx how long would it take me to charge the battery (riding time, with lights on, no other electric device attached )

Originally Posted by Warren

so why have i got to wait until the battery is fully charged before i carry out this test ?

and approx how long would it take me to charge the battery (riding time, with lights on, no other electric device attached )

what measurement is needed to tell how much drain an electrical application will have on a battery ? ie. heated grips.

Originally Posted by Warren

what measurement is needed to tell how much drain an electrical application will have on a battery ? ie. heated grips.

That would be Amps (Ampere's). The amount of electricity per second.

Heated grips IIRC, draw 4Amps (max) at 12volts, could be wrong on that though. Your starter motor, draws around 75Amps.

You need to put the system under load to get an Ampere reading though. So fire her up & stick the lights on.

I can't remember the specific values, but I did post somewhere on the forum. If you haven't found it by morning, I'll try find it. Basically, I went to town one day with my bike, and stuck the multimeter everywhere I could (oooeeerrr) under different conditions.

But now, is home time...

aah baph to my rescue

so your saying that i could find out how much charge is remaining in my battery using a multi meter ?