Battery Drains!

[Jbabin3xb]

I have some subs in the trunk that i just recently installed with the help of this forum ( thanks by the way). They worked perfectly for about 2 months then the battery started going low. the first time i was able to turn everything in the car off and get it to crank. but a week later same thing happened ( with the subs hooked up) except it gave a low batt. signal on a 50 street ( which means i was going about 56) everything started to dim so i turned off the radio thinking the subs were the reason an then everything lite up normally. when i got home ( which was plenty of road in my opinion for the alternator to get enough charge to the battery) it wouldn't crank. I jumped it and from then on left the 12's disconnected. and since then I've gotten the battery low light to blink occasionally but i just accelerate a little and it disappears the rest of the week

Suggestions? anything i can purchase to give the amp power but not drain the battery? and is this a common problem?

[djspawn00]

sounds like a parasitic drain, check the amp wiring, also do you have any capacitors installed? If not add these to meet your power needs. Sometimes depending on your system you may need a second battery. Also check your current battery? How old is it? Does it need require maintenance? some distilled water?

[Jbabin3xb]

i took it by firestone and they said the battery was fine. Also I've considered a second battery but i want that to be my last resort. And capacitors have come to mind but i have no clue which to get, would a capacitor be able to solve my problem? and whats the average cost of a decent one? thanks

[92Lex]

Caps are a waste of time/money. Get a high output alternator and call it a day.

[djspawn00]

Caps are a waste of time/money. Get a high output alternator and call it a day.

I wouldn't call caps a waste of many anymore than I would call high performance tires a waste of money... unless you're throwing them on your grandmas ford festiva.

[LLS]

the question is does it go dead while sitting or while driving.

If it goes dead while sitting you have a leaky power supply capacitor in the amps. It may be that you have such a problem and do not actually know it because it is weak by the time you start it. THEN compound that with a weak alternator and you got a big problem buck-O.

[gategem]

Large Electrolytic Caps won’t work because they will discharge through the same path the battery discharges. If you want to try one go to any electronic supply house and get one that will work over the temperature range and is rated for at least 35 volts. Caps are normally used for power supply regulation and high frequency filtering.

Check your charge rate with an ammeter and your changing voltage with a voltmeter. If the charging circuit is good then disconnect the battery and using wiring diagrams try taking resistance readings. It could lead you to the culprit.