How to check to ensure my battery is charging?

My 12v battery is basically dead all the time now and even right now it seems to be charged up but the car is still freaking out when I try to start it up and it takes a few tries for the big orange triangle (dash display) to go away.

I have a new battery on order but I am wondering if I could have burnt up the inverter as well. Could I use a multimeter to test for voltage at the battery when the car is on (kinda like you would an alternator) or is there another way?

 

<div class='quotetop'>QUOTE(eagle33199 @ Sep 14 2006, 10:00 AM) [snapback]319559[/snapback]</div>

The battery has been drained and charge at least 3 times that I can remember. Its been on ongoing thing that started about a month or 2 after I installed a 4oow rpm amplifier. I am assuming the invterter does not recharge the 12v battery very quickly so I may just be playing the system too hard too often without much time to recharge the battery.

The car runs perfectly fine once you get it running so then that means the inverter is working ok?

I'm going to get a new battery today and lay off the system for a bit until I can come up with a better plan lol

 

<div class='quotetop'>QUOTE(galaxee @ Sep 14 2006, 10:06 AM) [snapback]319565[/snapback]</div>

Figured that would work.

I tried it right before posting this and the charger was saying the battery was full and with the car on I was seeing 11.52v and the interior lights were flickering really bad. The car may not have been fully on though as I still had the orange triangle wanring thing on. I had only tried to turn it on to open the trunk since the door locks didnt seem to have enough power to work.

 

<div class='quotetop'>QUOTE(galaxee @ Sep 14 2006, 10:29 AM) [snapback]319578[/snapback]</div>

That was with the stereo off.

I'm going to fiddle with it to get it into normal running mode (IE I could actually put it in gear and move it) then check the voltage with the stereo for sure off (ensuring the amp is off as well).

brb lol

 

Ok, with the car on and not in freak-out mode I am seeing 11.95v.

I did find out that the amp stays on even though the stereo is off. I got a call so didnt check to see if it was staying on with the car off but I had checked that when I first installed it.

Also with the car on the interior lights were at full power and not flickering so that is good news.

I'll pick up the new battery and report back

 

<div class='quotetop'>QUOTE(San_Carlos_Jeff @ Sep 14 2006, 10:56 AM) [snapback]319597[/snapback]</div>

That is my main concern. I disconnected the amplifier completely before taking those readings. I just wasnt sure if I should be seeing 13.8-14v like a normal car or not.

 

K.I.S.S


So yeah, I went and bought a new battery after thinking I checked everyhting. Turns out one of the grounds to the chassis was loose. Lose enough it sparked and burnt the tip of mu finger when I wiggled it. Not sure how it worked itself loose but it sits somewhat out of view so I didnt see it was part of the mattery ground. I thought it was to just the amplifier.

Voltage with car on is now 14.09 with or without the amp on.


Thank you for the responses and I'll just go bury my head in shame now.

 

Very true

I cant remember which wire we tapped for power. I thought it turned off with the radio but apparently it doesnt. Just turns off with the car so its basically an ignition source. I will have to change that. Even though ther amp doesnt draw much in idle mode its still a draw.