Battery draw down
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Joined: Feb 2015
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Battery draw down
I have a 2006 S2000 with 212,000 miles on it. Not much wrong with it although it probably should have the clutch, pressure plate and bearing replaced. Frankly it has pretty much turned into a garage queen. The real problem is that it sits for 2 months and the battery drains down to about 4 or 5%. Any ideas on where to look for what is draining it?
Joined: Jul 2014
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From: Chesterfield VA
This is normal and expected. The remote lock system and some other electronics are always sucking amps from the battery Two weeks just sitting is enough to kill a weak battery. Your battery will not survive severe discharges very long.
Two simple solutions:
1. A battery "tender" connected when not in use. Since you're starting with a full battery this just keeps it there easily. Gotta have access to120vAC though. My car is on one now.
2. Battery disconnect switch on the negative terminal. Common marine/auto store part connects to the battery and the negative cable connects to the disconnect. Has insulated nut on top that just gets loosened to remove the battery from the system. In cold weather battery charge will remain good months. You'll need your radio code when you reconnect. I use this when parked at (for example) the airport for a couple of weeks (another car).
Lead acid batteries also experience self discharge all by themselves but this has proved minor in my experience killing batteries by several other means.
I'm betting your battery is already toast. Quick test:
Disconnect the battery Negative terminal. (Find your radio code first).
a. Charge with a modern battery charger of at least 10 amps capacity and charge for 24 hours. Don't skimp. Battery voltage will measure good in an hour but that's just the surface charge. 24 hours is necessary.
b. Disconnect charger and let the battery sit not attached to anything for 24 hours. Let it sit. Don't draw power from it.
c. Leaving the battery disconnected measure the voltage. Should be 12.7vDC. If it's lower than 12.6vDV go back to step (a) and try again -- but this rarely works.
Load test the battery. You can get a load tester at Harbor Freight and most auto stores for $25. These put large current drain in the battery and show the condition.
HTH,
-- Chuck
Two simple solutions:
1. A battery "tender" connected when not in use. Since you're starting with a full battery this just keeps it there easily. Gotta have access to120vAC though. My car is on one now.
2. Battery disconnect switch on the negative terminal. Common marine/auto store part connects to the battery and the negative cable connects to the disconnect. Has insulated nut on top that just gets loosened to remove the battery from the system. In cold weather battery charge will remain good months. You'll need your radio code when you reconnect. I use this when parked at (for example) the airport for a couple of weeks (another car).
Lead acid batteries also experience self discharge all by themselves but this has proved minor in my experience killing batteries by several other means.
I'm betting your battery is already toast. Quick test:
Disconnect the battery Negative terminal. (Find your radio code first).
a. Charge with a modern battery charger of at least 10 amps capacity and charge for 24 hours. Don't skimp. Battery voltage will measure good in an hour but that's just the surface charge. 24 hours is necessary.
b. Disconnect charger and let the battery sit not attached to anything for 24 hours. Let it sit. Don't draw power from it.
c. Leaving the battery disconnected measure the voltage. Should be 12.7vDC. If it's lower than 12.6vDV go back to step (a) and try again -- but this rarely works.
Load test the battery. You can get a load tester at Harbor Freight and most auto stores for $25. These put large current drain in the battery and show the condition.
HTH,
-- Chuck
Thread Starter
Registered User
Joined: Feb 2015
Posts: 4
Likes: 0
This is normal and expected. The remote lock system and some other electronics are always sucking amps from the battery Two weeks just sitting is enough to kill a weak battery. Your battery will not survive severe discharges very long.
Two simple solutions:
1. A battery "tender" connected when not in use. Since you're starting with a full battery this just keeps it there easily. Gotta have access to120vAC though. My car is on one now.
2. Battery disconnect switch on the negative terminal. Common marine/auto store part connects to the battery and the negative cable connects to the disconnect. Has insulated nut on top that just gets loosened to remove the battery from the system. In cold weather battery charge will remain good months. You'll need your radio code when you reconnect. I use this when parked at (for example) the airport for a couple of weeks (another car).
Lead acid batteries also experience self discharge all by themselves but this has proved minor in my experience killing batteries by several other means.
I'm betting your battery is already toast. Quick test:
Disconnect the battery Negative terminal. (Find your radio code first).
a. Charge with a modern battery charger of at least 10 amps capacity and charge for 24 hours. Don't skimp. Battery voltage will measure good in an hour but that's just the surface charge. 24 hours is necessary.
b. Disconnect charger and let the battery sit not attached to anything for 24 hours. Let it sit. Don't draw power from it.
c. Leaving the battery disconnected measure the voltage. Should be 12.7vDC. If it's lower than 12.6vDV go back to step (a) and try again -- but this rarely works.
Load test the battery. You can get a load tester at Harbor Freight and most auto stores for $25. These put large current drain in the battery and show the condition.
HTH,
-- Chuck
Two simple solutions:
1. A battery "tender" connected when not in use. Since you're starting with a full battery this just keeps it there easily. Gotta have access to120vAC though. My car is on one now.
2. Battery disconnect switch on the negative terminal. Common marine/auto store part connects to the battery and the negative cable connects to the disconnect. Has insulated nut on top that just gets loosened to remove the battery from the system. In cold weather battery charge will remain good months. You'll need your radio code when you reconnect. I use this when parked at (for example) the airport for a couple of weeks (another car).
Lead acid batteries also experience self discharge all by themselves but this has proved minor in my experience killing batteries by several other means.
I'm betting your battery is already toast. Quick test:
Disconnect the battery Negative terminal. (Find your radio code first).
a. Charge with a modern battery charger of at least 10 amps capacity and charge for 24 hours. Don't skimp. Battery voltage will measure good in an hour but that's just the surface charge. 24 hours is necessary.
b. Disconnect charger and let the battery sit not attached to anything for 24 hours. Let it sit. Don't draw power from it.
c. Leaving the battery disconnected measure the voltage. Should be 12.7vDC. If it's lower than 12.6vDV go back to step (a) and try again -- but this rarely works.
Load test the battery. You can get a load tester at Harbor Freight and most auto stores for $25. These put large current drain in the battery and show the condition.
HTH,
-- Chuck
Joined: Jun 2017
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From: Oregon
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Joined: Mar 2015
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From: Eastern Ontario
I have not experienced any issues with my battery tenders lowering the life expectancy of my batteries as of yet. Winters are a little more harsh up here in Canada but my cars are stored in a heated environment throughout the winter.
Joined: Jun 2017
Posts: 1,318
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From: Oregon
I've had good luck using a Deltran Battery Tender on my motorcycle batteries. I would think that if you live in a colder climate, unless your battery is going to be stored in a heated environment, you would be better off with a good battery tender (not a simple trickle charger) as opposed to simply disconnecting the battery.
