My 89 crx si with a ZC swap is running sweet! The car sat for a while before the project was completed and I wonder if I killed the battery from just sitting to long (9 months) and now it wont hold a charge because the battery goes flat in a day or so.
When a voltage detector light is placed in line on the negative battery terminal there is a dim but steady pulse which i believe is the on board clock. When I disconect the fuse to the clock, the light goes dimmer and the pulse disappers but a slight current drain is still there. I pulled all the remaing fuses and the dim light was still present. When i disconnect the plug in the upper LH face of the fuse panel all evidence of volt drainage stop. I don't know what current leakage is allowed, if any, or what volt drainage is desingned into the system.
Can anyone shed some light on this or point me in the right direction?
Thanks.

 

its so small that ur battery shouldnt be drained that bad in a day!? are u looking for a parasitic drain on ur battery?

 

Parasitic drain was/is suspect. I was thinking about a new battery, but don't want to spend the money if that's not the problem. Got any suggestions?

 

u need 12 voltage to start a car

 

^Ignore this

typical drain on our cars should be under .05A with the key off and all accessories off. You may have to wait 20-30 secs for the ECU to shut down. Some aftermarket radios have a high amp draw w/ key off.

Do you have access to a battery load tester? Another way to test for a dead battery is to hook a multimeter up to the battery and start the car. Watch the meter and see how low the voltage drops when turning the starter. Anything under 9V(with a good charged battery) is recommended to be replaced.

 

i know what im talking about u need ATLEAST 12 voltage to start a car

look it up

 

Thank you gunmetal, that was exactly what i was looking for. I checked the amperage draw key out and it was .031 amps. with the aftermaket stereo the draw was 2.1 key off. That higher draw in conjunction with a weaker batt that won't maintain a charge was the problem.

 

So what happens when you have 12 volts and 15 cranking amps... will the car start... I mean you have 12 volts it has to start... RIGHT????

 

--------------------------------------------------------------------------------

i should be 12 volts off and 15 volts when on

 

Take it to autozone or pepboys and theu test it for free!!

 

miguey310 you are fail you can have all the voltage you want but without amps you are going no where go back to autozone.


to op your battery is sulfated if you have acees to a battery charger do a quick charge test or replace battery

 

op, you nailed it.. if that stereo was left in and was drawing 2.1 amps the whole time, that is MORE than enough to kill the battery over 9 months.

A really simple way to prove it is to figure out the Amp/hour rating of your battery, which is generally printed on the battery somewhere. then you can figure out roughly how long your battery will last by using the formula

amp hour rating of battery / observed parasitic amp draw = time in hours your battery will stay "charged"

for your example, assuming you have a 200 amp hour battery and a 2.1 amp draw from the stereo, you get

200 / 2.1 = 95.xx hours

or about 4 days. So your battery died roughly only 4 days after you parked the car, assuming the stereo was installed at that point. environmental factors also affect the numbers, but as a rough estimate, that equation above will hold true.

 

im taking bout the battery

 

If u have ur car sitting for that long for sure it will get weak. I like the batter tender. Good investment