Since the installation of my car audio system I've had two batteries fail prematurely. Power amps consist of a JL Audio 300/2 and an old a/d/s 4 channel amp. When the car is off the 300/2 draws 1.5 mA and the a/d/s draws 45 mA.
I just wonder if this is normal or is there something wrong with the a/d/s amp.
Thanks, Mike
I just wonder if this is normal or is there something wrong with the a/d/s amp.
Thanks, Mike
Assuming that the batteries were in the vehicle for months (correct if wrong)...
If the engine started easily every time you used the vehicle, current draw from the amp isn't the problem. If you used the vehicle only a couple of times a month and the batteries were very nearly dead each time you started the engine, the current draw may have been an issue.
Batteries are most commonly damaged by excessive charging voltage, by remaining in a discharged state for an extended period of time or by vibration.
If the engine started easily every time you used the vehicle, current draw from the amp isn't the problem. If you used the vehicle only a couple of times a month and the batteries were very nearly dead each time you started the engine, the current draw may have been an issue.
Batteries are most commonly damaged by excessive charging voltage, by remaining in a discharged state for an extended period of time or by vibration.
Hi Mike,
You can try this for starters. Checking the amps one at a time, Make sure that the amps are both turned off. Disconnect the main ground cable from the amp (a/d/s). Place a volt meter's positive probe on the negative power terminal, and the negative probe on the ground cable's copper strands. You should see a reading of zero volts (0). Do the same w/the JL Audio amp in the exact same way.
If these amps are stealing from the battery with the power off, this method will tell you. If one of the amps is drawing a couple of volts, there's your problem. If not, do the same w/the main negative battery cable at the battery, and note the voltage reading; your going to have to find the culprit by pulling all of the fuses from the fuse box... one by one. Good luck!
rigtec, cheers
Perry and Rigtec,
Thanks for your replies. I measure 14.2 volts with the engine running so I think the charging system is OK. I just wonder if it is normal for power amps to draw current when the ignition is off. Perhaps the problem is the cheap batteries I have been buying from Fleet Farm (local big box store). The guy that gave me a jump last time told me to buy an Interstate battery.
Thanks for your replies. I measure 14.2 volts with the engine running so I think the charging system is OK. I just wonder if it is normal for power amps to draw current when the ignition is off. Perhaps the problem is the cheap batteries I have been buying from Fleet Farm (local big box store). The guy that gave me a jump last time told me to buy an Interstate battery.
Testing as you suggested will likely give a reading equal to the battery voltage for the amp drawing 45ma. He already knows that the amps are drawing current (which is normal for some amps and is not a problem for most vehicles).
With the 48ma of current draw, how long should it take for the battery to go dead enough not to start the vehicle? If it's significantly longer than the time between uses of the vehicle, the amps are not the problem.
With the 48ma of current draw, how long should it take for the battery to go dead enough not to start the vehicle? If it's significantly longer than the time between uses of the vehicle, the amps are not the problem.
Thanks Perry,
You have answered my question. I will purchase a better battery
Rigtec, Perhaps I did not make it clear but I have already made measurements as you suggested. The JL 300/2 draws 1.5 mA and the a/d/s amp draws 43mA. The car without the amps connected draws another 20mA. That makes a total of 64.5mA. This seems to be enough to run down my battery with the little amount that the car is driven.
Thanks for your replies.
Mike
You have answered my question. I will purchase a better battery
Rigtec, Perhaps I did not make it clear but I have already made measurements as you suggested. The JL 300/2 draws 1.5 mA and the a/d/s amp draws 43mA. The car without the amps connected draws another 20mA. That makes a total of 64.5mA. This seems to be enough to run down my battery with the little amount that the car is driven.
Thanks for your replies.
Mike
if the "new battery" goes flat it could be time to consider uprating the alternator/generator if everything was normal before the install it could be your amps are consuming the lions share of the current produced leaving little to no current available for whatever battery you have and allow stand by conditions to finish the job...
if the "standby" current draws are as high as you stated it certainly merits checking the standby supply of the "a/d/s" amp that one seems high me thinks!
in my tenure as a car audio/remote starter/accessories installer current draws above 30 milliamps where always a cause for concern
if the "standby" current draws are as high as you stated it certainly merits checking the standby supply of the "a/d/s" amp that one seems high me thinks!
in my tenure as a car audio/remote starter/accessories installer current draws above 30 milliamps where always a cause for concern
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