1998 S70 Battery drain

Woodchimps · Post by **Woodchimps** » 04 Jun 2007, 21:51

Daughters car(138000 mi.) drains the battery. Did the alternator test in Chilton manual with OK reading of 0.5 volts above battery voltage with no load on system at 1500 rpm. Only had 0.3 volts above battery voltage with AC & lights on at 2000 rpm. Does this mean that the alternator needs replacement or could it be the voltage regulator? Do I have to take alternator to a shop to have a bench test or can I do further testing with it in car? Thanks in advance for any suggestions.

KLC

Post by **MadeInJapan** » 05 Jun 2007, 05:58

You might just have an internal light on that you're unaware of....often it's the latch on the glove box that isn't making good contact, allowing the glove box light to stay on and this will drain the battery...at least check it as well as the trunk lid light.

Post by **pfeener** » 05 Jun 2007, 06:06

Does it drain the battery when it just sits there overnight or does it drain the battery when you drive it?

Woodchimps · Post by **Woodchimps** » 05 Jun 2007, 06:39

After battery charge, daughter drives with lights, radio, A/C on. After ~ 2-3 days, will again be hard to start with low battery voltage.

bobsnow100 · Post by **bobsnow100** » 05 Jun 2007, 10:21

I think you need a new battery.

Post by **Ozark Lee** » 05 Jun 2007, 12:34

After battery charge, daughter drives with lights, radio, A/C on. After ~ 2-3 days, will again be hard to start with low battery voltage.

You local Autozone / O'Reilly / Advance Auto Parts stores will test both the battery and the alternator for free. Keep in mind that they are in the business of selling batteries and alternators.

...Lee

Post by **pfeener** » 05 Jun 2007, 20:21

Sounds like the alternator.

I assume after 2-3 days with the battery low, you're recharging the battery and it takes the charge and will last another 2-3 days. If that's the case, I would assume your battery is OK.