electrical issues :(

[MaLicE]

ok car was running like a dream!

past couple days i have noticed that it doesnt turn over as quickly making me think the battery was a little dead...

anyway today driving along my greddy electronic gauges start dancing about on their own and the radio kept turning on and off, get to a set of lights, revs drop i try giving it some gas and it dies, not enough juice to even run the hazards... got recovered and delivered home, stuck a jumper pack on the battery and it started instantly, it revs etc fine, disconnected the bat pack and it still ran, left it a couple mins and noticed the gauges dancing about again then the radio turned off and it died again...

the battery is the stock trust battery that came with the car from japan so its old lol, im just wondering could it be the alternator?? where would i put the probes on a volt meter to check the voltage coming from the alt?? any other checks??

[batman]

check volts on battery with engine off should be constant 12 ish  then fire it up should run between 12 and 14 no more really  could be a bad earth dodgy alternator or charge relay chack all mate

[MaLicE]

where is the charge relay mate??

[batman]

i dunno some cars have them might be in a manual as a voltage control curcit or something