Battery Drain with Battery Tender attached
10-29-2012, 04:06 PM
#1
Intermediate
Thread Starter
Battery Drain with Battery Tender attached
Recently replaced the battery in my 89 coupe about 4 months ago. Attached a battery tender as always and all was well for a time. Recently the battery tender flashed green which indicates 80% charge and this lasted for a couple of months. When I drove the car then hooked up the tender afterwards it would show a constant green light on the battery tender for about 4 days or so, then begin flashing green, red light constant. Last night I noticed the red light on and the battery was dead. I realise I have a drain of some sort, but I am stumped why the battery tender wouldn't at least hold to 80% like it had been. Any ideas?
My new-to-me ZR1 is doing something similar.
10-29-2012, 07:36 PM
#3
Race Director
When all was well, if the tender was not hooked up at night, was the battery dead by daytime?
10-29-2012, 07:48 PM
#4
Both of you need to check first for "parasitic" draw on the vehicle. I'd suggest a "google search" for it and read some tutorials. It's very straight forward and you'll need a DMM to accomplish it.
It need NOT be an expensive purchase and you'll eventually need one if you intend on DIY repairs and diagnostics. I wouldn't "cheap-out" on one but it doesn't need to be a major purchase either. Less than 30 minutes and you'll know if you've a problem or NOT. You won't know where but you'll know if there's a problem.
OP - I believe some/most have a 72 hour timer of sorts and if there were a problem with a "sulfated" battery or other issues it might actually "shut down". Read the explanation of lamps on your specific model. Maybe check entire charging system.
It need NOT be an expensive purchase and you'll eventually need one if you intend on DIY repairs and diagnostics. I wouldn't "cheap-out" on one but it doesn't need to be a major purchase either. Less than 30 minutes and you'll know if you've a problem or NOT. You won't know where but you'll know if there's a problem.
OP - I believe some/most have a 72 hour timer of sorts and if there were a problem with a "sulfated" battery or other issues it might actually "shut down". Read the explanation of lamps on your specific model. Maybe check entire charging system.
10-30-2012, 09:09 AM
#5
Intermediate
Thread Starter
10-30-2012, 09:14 AM
#6
Intermediate
Thread Starter
Both of you need to check first for "parasitic" draw on the vehicle. I'd suggest a "google search" for it and read some tutorials. It's very straight forward and you'll need a DMM to accomplish it.
It need NOT be an expensive purchase and you'll eventually need one if you intend on DIY repairs and diagnostics. I wouldn't "cheap-out" on one but it doesn't need to be a major purchase either. Less than 30 minutes and you'll know if you've a problem or NOT. You won't know where but you'll know if there's a problem.
OP - I believe some/most have a 72 hour timer of sorts and if there were a problem with a "sulfated" battery or other issues it might actually "shut down". Read the explanation of lamps on your specific model. Maybe check entire charging system.
It need NOT be an expensive purchase and you'll eventually need one if you intend on DIY repairs and diagnostics. I wouldn't "cheap-out" on one but it doesn't need to be a major purchase either. Less than 30 minutes and you'll know if you've a problem or NOT. You won't know where but you'll know if there's a problem.
OP - I believe some/most have a 72 hour timer of sorts and if there were a problem with a "sulfated" battery or other issues it might actually "shut down". Read the explanation of lamps on your specific model. Maybe check entire charging system.
10-30-2012, 10:02 AM
#7
Team Owner
Digital Multi Meter. You need one that can display current draw in at least tenths of amps (look for a "mA' selection on the DMM). Sears would be a good place to get one' check out the Craftsman Autoranging Multimeter #82141, about $23
Most tenders don't provide much more than 1 to 1.4 amps. It's possible that there is a current draw in the car that equal to or even greater than what the tender can supply. You could also have a bad battery. Have it load tested to see if it needs replacement. Do this first before looking for parasitic current draws.
Most tenders don't provide much more than 1 to 1.4 amps. It's possible that there is a current draw in the car that equal to or even greater than what the tender can supply. You could also have a bad battery. Have it load tested to see if it needs replacement. Do this first before looking for parasitic current draws.
10-30-2012, 10:12 AM
#8
Digital Multi Meter. You need one that can display current draw in at least tenths of amps (look for a "mA' selection on the DMM). Sears would be a good place to get one' check out the Craftsman Autoranging Multimeter #82141, about $23
Most tenders don't provide much more than 1 to 1.4 amps. It's possible that there is a current draw in the car that equal to or even greater than what the tender can supply. You could also have a bad battery. Have it load tested to see if it needs replacement. Do this first before looking for parasitic current draws.
Most tenders don't provide much more than 1 to 1.4 amps. It's possible that there is a current draw in the car that equal to or even greater than what the tender can supply. You could also have a bad battery. Have it load tested to see if it needs replacement. Do this first before looking for parasitic current draws.
