Question-------------------------
Followup To
Question -
tom,
i have a 92 subaru legacy. stock stereo, am/fm cassette with 4 speakers. i added a 900ish watt 4 channel amp that is bridged to 2 15" woofers. the car is driven to work and back. about a total of 30 minutes a day. on the way to work i run the lights. i also listen to stereo at lunch without starting the car. the combination of things, drains battery down about every 3-4 days. i charge it up with charger about every 3 days, to stay ahead of dead battery problem. now its cold and the problem has become more frequent. what can i do to get more battery life? i have considered adding a second battery. if so, do i hook it in parallel to the first? do i let it stand alone and run stereo only, charging it as needed. Current battery is about 1 year old. please let me know if you need more info.
dugger
Answer -
Dugger,
The problem may not be the battery, rather the alternator simply can't charge the battery faster than what you are taking out of it. You can install a second battery in the trunk close to the amp to supply added operating current for it and having it charge through a diode isolator. A 900 watt amp should have a heavy duty battery and a alternator that has at least 80-100 amp output to charge the battery/s, lastly with a 900 watt amp you should not play the stereo without the engine running or you will quickly discharge the battery.
TOM,
T&D ELECTRONICS
tdeser@zoominternet.net
thank you tom,
more info please.
what is diode isolator? where would i get one? are there different sizes?
can i use the current 8 guage (think its 8) wire already running from battery to amp to hook up second battery? where do i ground second battery?
i think alternator was 103 amps at 3,000 rpm. i dont know if that is alt at 3 or motor at 3.
i will definatly stop listening to stereo with motor not running, at least not run amp. (rem wire is on a toggle)
thank you again for your help!
dugger
AnswerDugger,
If you still have the install info for the amp, take a look at it to see what size wire they suggest using to install the amp. A good rule to go by is to use a wire that is slightly smaller than the hole that the wire goes into. A 900 watt amp should be hooked up with a 4 gauge wire on both hot and ground. keep the ground wire as short as possible. When using a second battery you must keep the ground as short as possible and connect it to the vehicle frame. You can purchase a diode isolator at most good auto parts stores. The diode isolator will allow charging current from the alternator to travel to the battery in the trunk, with the isolator installed if the battery in the trunk gets drained it won't cause the starting battery to drain also.
TOM,
T&D ELECTRONICS
tdeser@zoominternet.net
