Jump to content

Why does the battery drain? Cant keep it connected.


Reattatude
 Share

Recommended Posts

Hi, Guys

 

1989 Coupe, it has a very slow drain on the battery so I have to disconnect the battery when it sits for long period of time.

The battery will totally empty if left connected for a few weeks.

Where would you look to troubleshoot a power leak or faulty ground??

Ive left off getting this fixed and just bought a new battery (again) and this one needs to last.

 

open to all suggestions but hopefully its not in the electrical harness that runs to the back under the seats... 🙎‍♂️

Link to comment
Share on other sites

A friend that worked at GM as a field engineer said to check the "Rap, retained accessory power module."  It's the one that keeps the power on to the windows after the ignition is turned off.  It does the radio as well.   It's suppose to be for 10 seconds I think,  but when they fail,  they stay powered on.  The easiest way to check is to shut the car off (ignition and accessories off)  and leave the window down with the door closed.  Go over to the car a few minutes later and try the window.   If it still has power,  then it's that relay.  He said they commonly failed back in the day and were always being replaced. 

He also said you can check it with the radio.  If the radio will play a half after after the car is off it's bad as well. 

Edited by auburnseeker (see edit history)
Link to comment
Share on other sites

What time frame are we talking about? Days, weeks?

There is a constant parasitic drain for the 'keep alive' circuits, that, over time could kill a battery, ESPECIALLY one that's old and weak.

I think that drain is around 20 ma.

The previous poster talks about the 'retained accessory power' feature that's good for about 10 minutes of accessory use after shutdown (more than just windows). I've never seen this feature to fail as suggested, but YMMV. 

I've had this dead battery issue on my seldom driven '88; I just keep a battery tender on it.

Link to comment
Share on other sites

Has anyone with this problem tried the check I mentioned?  Curious if this is anyone's problem.  I have another friend with a Reatta that does the same thing,  but he let the new battery go dead last year and is just to easily distracted to get the battery out charge it,  put it back in and try it.   He pushed the car out of the garage to be able to set up for a garage sale and it took him almost 4 months before he finally got around to having me go over and help him push it back in.  

Link to comment
Share on other sites

Reattas are a little different from your run of the mill car when testing for what is draining the battery.  A Reatta will drain a good battery after a few weeks of sitting without being started because of all the electronics that are being powered even when the key is off.  Here are instructions on how to check to see if the battery drain is normal. 
How To Measure Battery Drain

Link to comment
Share on other sites

7 hours ago, harry yarnell said:

...There is a constant parasitic drain for the 'keep alive' circuits, that, over time could kill a battery... 

I've had this dead battery issue on my seldom driven '88; I just keep a battery tender on it.

 

I've heard that Cadillac Allantes have the same,

or a similar, problem with their batteries becoming discharged.

I think Harry and Ronnie may have the answer for your Reatta.

Edited by John_S_in_Penna (see edit history)
Link to comment
Share on other sites

7th generation Rivieras' (86-93) were prone to parasitic battery drain, also.  I too attach a battery tender if/when I leave my 91 Reatta unattended for more than a week during spring/summer/fall.  During winter the tender is continually hooked up when the Reatta is in storage.

 

Check out Ronnie's link to the ROJ above...good info.  

  • Like 1
Link to comment
Share on other sites

On 2/23/2019 at 3:19 PM, SCOTT's 90's said:
On 2/23/2019 at 10:12 AM, auburnseeker said:

A friend that worked at GM as a field engineer said to check the "Rap, retained accessory power module."  It's the one that keeps the power on to the windows after the ignition is turned off.  It does the radio as well.   It's suppose to be for 10 seconds I think,  but when they fail,  they stay powered on.  The easiest way to check is to shut the car off (ignition and accessories off)  and leave the window down with the door closed.  Go over to the car a few minutes later and try the window.   If it still has power,  then it's that relay.  He said they commonly failed back in the day and were always being replaced. 

He also said you can check it with the radio.  If the radio will play a half after after the car is off it's bad as well. 

 

On 2/23/2019 at 12:15 PM, harry yarnell said:

What time frame are we talking about? Days, weeks?

There is a constant parasitic drain for the 'keep alive' circuits, that, over time could kill a battery, ESPECIALLY one that's old and weak.

I think that drain is around 20 ma.

The previous poster talks about the 'retained accessory power' feature that's good for about 10 minutes of accessory use after shutdown (more than just windows). I've never seen this feature to fail as suggested, but YMMV. 

I've had this dead battery issue on my seldom driven '88; I just keep a battery tender on it.

Is your Reatta parked outside in the cold if so this will also impact the battery, especially if it is old and weak. Either way I always keep my battery on a tender from Fall to Spring if I am not driving it within 5 days.

 

 

Harry, The car is garage kept and the "constant parasitic drain" factor would be relavant in my case, the car is seldom driven, well has been barely driven even in the warmer months I will admit.

 

Auburn,  I was not aware of the RAP relay and thank you, I will very definitely perform the test. Though after reading all the responses

here I think I should just drive her on a regular basis as weather permits. I am guilty of "Reatta Neglect" I fear.

 

By battery tender you mean a Trickle Charger I presume?  Ive have used one during the winter but I think that particular battery was too far gone and she didnt fire up when I tried to start the car.  I have a new battery since January and have fired up the car a couple of times and disconnected it each time, no trickle charger. I am not surprised the Allante has similar battery drain issues! 

 

I will report back when I have performed that RAP relay test. Thanks to all

 

 

 

  • Like 1
Link to comment
Share on other sites

9 hours ago, Reattatude said:

By battery tender you mean a Trickle Charger I presume? 

 

"Battery Tender" is a specific brand of product,

made by Deltran.  It is widely used in the hobby,

and comes in 6-volt, 8-volt, and 12-volt versions--good

for all sorts of vehicles.  The Battery Tender puts out a

small-amperage charge, and then automatically

turns off when the battery is charged.  Their literature

emphasizes that it is NOT a trickle charger.

 

Their internet site is www.batterytender.com.

Their telephone is (386) 736-7900, or toll-free (877) 456-7901

(Deland, Florida).

 

image.jpeg.31ac80b033c8b633276d6865a6530277.jpeg

 

Edited by John_S_in_Penna (see edit history)
Link to comment
Share on other sites

13 hours ago, John_S_in_Penna said:

 

"Battery Tender" is a specific brand of product,

made by Deltran.  It is widely used in the hobby,

and comes in 6-volt, 8-volt, and 12-volt versions--good

for all sorts of vehicles.  The Battery Tender puts out a

small-amperage charge, and then automatically

turns off when the battery is charged.  Their literature

emphasizes that it is NOT a trickle charger.

 

Their internet site is www.batterytender.com.

Their telephone is (386) 736-7900, or toll-free (877) 456-7901

(Deland, Florida).

 

image.jpeg.31ac80b033c8b633276d6865a6530277.jpeg

 

 

Oh I see, so why didnt yall say Battery Tender ™ ?

 

  • Haha 1
Link to comment
Share on other sites

I have a 1989 Riviera, unfortunately I have to leave it outside for a few months. Was wondering about these solar battery tenders that lay on the dash and  plug into lighter  or have wires that go to the battery.

Anyone have any thoughts?

Thanks

Link to comment
Share on other sites

17 minutes ago, CHAS1 said:

I have a 1989 Riviera, unfortunately I have to leave it outside for a few months. Was wondering about these solar battery tenders that lay on the dash and  plug into lighter  or have wires that go to the battery.

Anyone have any thoughts?

Thanks

i think a big one would help.i suspect they come in different sizes.

Link to comment
Share on other sites

On 2/26/2019 at 8:42 PM, John_S_in_Penna said:

"Battery Tender" is a specific brand of product,

made by Deltran.  It is widely used in the hobby,

and comes in 6-volt, 8-volt, and 12-volt versions--good

for all sorts of vehicles.

That's a good brand. I made the mistake of picking up a cheap float charger from Harbor Freight. I believe it was a Centech brand. It didn't last 3 months.

  • Like 1
Link to comment
Share on other sites

21 minutes ago, CHAS1 said:

Looking for Solar for outdoor storage

any thoughts on Solar?

Seems like it would have a limited amount of time exposed to the sun if it was on the dash.  Was it designed to be on the roof or on the dash? What is the amperage of the solar panel? 

Link to comment
Share on other sites

A lot depends on the condition and age of the battery. I buy only AGM batteries and am having some from 2009-2010 fail. I do have little float chargers on anything that sits for a while. If I leave everything connected even my '70 has a parasitic drain (the clock). Anything not going to be driven for a while, I disconnect the battery.

 

Modern cars (this century) are very intolerant of sub-standard batteries. The keep-alives are integrated into everything instead of just using non-volatile memory. Now it is important to always remove the negative battery terminal first.

 

Finally being able to get an accurate look at the battery's state is important. I have a BT-360 (many on ebay) that tells me a lot about both the battery and the charging system. These are both more capable and less expensive than the one from HF.

Link to comment
Share on other sites

My Reatta pulls about 20 milliamps (.02 amps) continuously with the key off. I believe that would be about .24 watts. It seems like the panel should work but it would depend on how many watts it would put out in a 24 our period based on the amount of light it received.

Link to comment
Share on other sites

About 10 or so years ago I bought a solar panel from Cal Ranch (Not sure if you have one where you live) for about $30. It is 15" square (They had other larger sizes too) with an aluminum frame plus it is weather resistant. It came with several adapters and I even used it to charge my tablet one year, but it took several hours to charge to 100%. It also works on cloudy days but not very well, full sunny days are best.

Edited by SCOTT's 90's (see edit history)
Link to comment
Share on other sites

Wanted to add that on my 1989 Riviera if I remove the battery for the winter like I just did, It runs terrible once I reinstall the battery and drive it. Takes a while for everything to return to being drivable. No power almost felt like clogged Cat converter. Solar charger is my answer. Car is for sale so do not want to get to involved.

All is well now.

Thanks to all

Link to comment
Share on other sites

On 3/7/2019 at 9:15 PM, Ronnie said:

That's a good brand. I made the mistake of picking up a cheap float charger from Harbor Freight. I believe it was a Centech brand. It didn't last 3 months.

 

Harbor Freight, arghh - never again, I did the same thing. Although, HF is good for some tools most do not stand up well.

Link to comment
Share on other sites

HF is like JC Whitney (Washawski for westerners) you have to know exactly what you are buying (never saw a set of 3/4 size replica tire irons before). That said I have a Whole Bunch (c) of little HF chargers. They only put out about 80 ma so can't do much harm, just leave one on cars I am not driving. Get them as freebies and worth it.

Edited by padgett (see edit history)
Link to comment
Share on other sites

I have a unit on my battery that keeps track of the voltage and when it reaches 11.7 volts, it shuts everything down. That way you always have enough to start the car.

The only draw-back is you can't charge through it but you can shut it off to charge the battery.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...