Battery goes dead after sitting two weeks
08-21-2014, 12:38 PM
#2
Le Mans Master
08-21-2014, 02:45 PM
#5
Le Mans Master
You could have a parasitic drain. If you do, it should not be a big one as most we see will drain a battery in a day or over several days. There could be any number of reasons for a drain like what was said before. It is easy to test for if you have an ammeter to measure current. Most multi meters can do that. Normal draw/drain is around 17 to 22 milliamps. It can be measured by removing the battery negative cable and putting the ammeter between the removed cable and the negative post of the battery.
At first the draw will be very high in the amps range and then when the system goes into the "sleep" mode it should drop down to the above range. This could take a few minutes and when it finally settles down and does not drop any more that well be the total drain. Normal or above normal.
If you want to do that and find you have an above normal drain then we can tell you how to proceed from there to find the cause.
If you want to learn a little more on this just do a search or I can provide a link for you later when I get home.
At first the draw will be very high in the amps range and then when the system goes into the "sleep" mode it should drop down to the above range. This could take a few minutes and when it finally settles down and does not drop any more that well be the total drain. Normal or above normal.
If you want to do that and find you have an above normal drain then we can tell you how to proceed from there to find the cause.
If you want to learn a little more on this just do a search or I can provide a link for you later when I get home.
08-21-2014, 10:25 PM
#6
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A battery tender on a car that is not driven often will save a lot of headaches.
08-21-2014, 11:09 PM
#8
Team Owner
Battery goes dead after sitting two weeks
I agree, it sure does.
I agree, it sure does.
08-22-2014, 08:47 PM
#10
You could have a parasitic drain. If you do, it should not be a big one as most we see will drain a battery in a day or over several days. There could be any number of reasons for a drain like what was said before. It is easy to test for if you have an ammeter to measure current. Most multi meters can do that. Normal draw/drain is around 17 to 22 milliamps. It can be measured by removing the battery negative cable and putting the ammeter between the removed cable and the negative post of the battery.
At first the draw will be very high in the amps range and then when the system goes into the "sleep" mode it should drop down to the above range. This could take a few minutes and when it finally settles down and does not drop any more that well be the total drain. Normal or above normal.
If you want to do that and find you have an above normal drain then we can tell you how to proceed from there to find the cause.
If you want to learn a little more on this just do a search or I can provide a link for you later when I get home.
At first the draw will be very high in the amps range and then when the system goes into the "sleep" mode it should drop down to the above range. This could take a few minutes and when it finally settles down and does not drop any more that well be the total drain. Normal or above normal.
If you want to do that and find you have an above normal drain then we can tell you how to proceed from there to find the cause.
If you want to learn a little more on this just do a search or I can provide a link for you later when I get home.
08-22-2014, 11:40 PM
#12
Le Mans Master
Once you determine you have a drain with an ammeter what I recommend first is to listen to each fuse box and see if you hear any relays operating. If not, then place your hand on each relay to see if any of them feel hot. That can be the start if you find something like that is happening.
If nothing shows up you can hear of feel then I recommend you separate the two fuse boxes from each other. This is easy and done by removing the Red cable from the engine fuse box that feeds the passenger fuse box. It is on the right rear side of the engine fuse box. There is a stud there where the large Red wire from the battery connects. Just remove the nut and disconnect the large Red wire feeding the passenger fuse box and reattach the Red battery cable.
What you will be doing is measuring the drain with an ammeter to see if disconnecting the passenger fuse box causes the drain to go away or not.
If removing the feed to the passenger fuse box you then see you have eliminated the drain then you know it is something related to those circuits. If it does reduce the drain then you know it is related to the engine fuse box.
Once you basically know where it is then you can remove fuses and relays to see where the drain is coming from.
If nothing shows up you can hear of feel then I recommend you separate the two fuse boxes from each other. This is easy and done by removing the Red cable from the engine fuse box that feeds the passenger fuse box. It is on the right rear side of the engine fuse box. There is a stud there where the large Red wire from the battery connects. Just remove the nut and disconnect the large Red wire feeding the passenger fuse box and reattach the Red battery cable.
What you will be doing is measuring the drain with an ammeter to see if disconnecting the passenger fuse box causes the drain to go away or not.
If removing the feed to the passenger fuse box you then see you have eliminated the drain then you know it is something related to those circuits. If it does reduce the drain then you know it is related to the engine fuse box.
Once you basically know where it is then you can remove fuses and relays to see where the drain is coming from.
08-23-2014, 08:34 AM
#14
Burning Brakes
08-23-2014, 09:57 AM
#16
Le Mans Master
08-23-2014, 03:16 PM
#18
Safety Car
Same here. Even with a good battery mine is good for 2 weeks; If I push it to 3 it seems to turn over more slowly than usual but has never not started for me. I keep a battery tender on it now if it goes more than 7-10 days without getting driven so I don't keep draining the battery down.
08-23-2014, 10:45 PM
#20
Racer
I had a mercedes sl on a battery tender for a year with out starting it, got in hit the key, once the fuel got pumped up it started and ran great. keep the computer working and that made the difference.
