944 Occasionally Dead Battery - What next?
01-12-2013, 05:32 PM
#16
Rennlist Member
Thread Starter
Okay, took a shot at it today. I have a 42mA parasitic drain on the battery. I pulled every fuse and relay without affecting that value so it sounds like the factory alarm could well be the blame here.
With the window relay enabled right after key-off, I was getting in the 80mA range. I also get around that range if one of the doors is open. However I should note that I'm not sure if I have any interior lights installed right now. I also don't have a bulb in the glove box, as it turns out.
I'm not entirely sure of the amp hour rating of my battery. I mispoke earlier when I said I had an Optima RedTop. That's the nice battery. I have the less nice Duralast, but it also has a red top. Anyway, it seems that a typical number for a non deep cycle car battery might be around 40Ah.
Say mine is a bit flat and also subtract a bit for the winter weather. Let's say 20Ah. And let's round the draw up to 50mA. That means the battery will go dead in about 400 hours, or a little over two weeks.
With a fresh 50Ah Optima RedTop battery and just a 42mA draw, you will get 7 weeks before the battery is kaput. Best case scenario I reckon.
I think I'm going to go the solar route which should easily make up the 42mA until it gets warm enough for me to crawl in to the ECU area and disconnect the damn power suck of an alarm system.
With the window relay enabled right after key-off, I was getting in the 80mA range. I also get around that range if one of the doors is open. However I should note that I'm not sure if I have any interior lights installed right now. I also don't have a bulb in the glove box, as it turns out.
I'm not entirely sure of the amp hour rating of my battery. I mispoke earlier when I said I had an Optima RedTop. That's the nice battery. I have the less nice Duralast, but it also has a red top. Anyway, it seems that a typical number for a non deep cycle car battery might be around 40Ah.
Say mine is a bit flat and also subtract a bit for the winter weather. Let's say 20Ah. And let's round the draw up to 50mA. That means the battery will go dead in about 400 hours, or a little over two weeks.
With a fresh 50Ah Optima RedTop battery and just a 42mA draw, you will get 7 weeks before the battery is kaput. Best case scenario I reckon.
I think I'm going to go the solar route which should easily make up the 42mA until it gets warm enough for me to crawl in to the ECU area and disconnect the damn power suck of an alarm system.
