Why does the battery drain? Cant keep it connected.

[Reattatude]

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... 🙎‍♂️

[39BuickEight]

Just a couple of basic things to check first without getting too far into it would be to make sure the glove box and trunk lights are actually turning off when closed.

[handmedownreatta]

mine does the same thing.

 

[auburnseeker]

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 February 23, 2019 by auburnseeker (see edit history)

[Hill1]

If your alternator has a bad diode, your battery can drain. The bad alternator diode can cause the circuit to charge even when the engine is shut off, and you end up in the morning with a car that won't start.

Exide EB604 60Ah Excell 390A car batteries

[harry yarnell]

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.

[SCOTT's 90's]

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.

[handmedownreatta]

1 hour ago, SCOTT's 90's said:

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.

i have a battery tender on mine too but its a pain.

[auburnseeker]

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.  

[Ronnie]

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

[John_S_in_Penna]

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 February 24, 2019 by John_S_in_Penna (see edit history)

[dship]

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.  

[handmedownreatta]

On 2/23/2019 at 8:07 AM, handmedownreatta said:

mine does the same thing.

 

i checked mine today.two month old battery,driven week before last.battery completely dead.

[Reattatude]

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

 

 

 

[John_S_in_Penna]

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).

 

 

Edited February 27, 2019 by John_S_in_Penna (see edit history)

[Reattatude]

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).

 

 

 

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

 

[Reattatude]

I performed the simple test and The RAP relay on my car is functioning as it should -- the windows stayed energerized

at least 10 minutes and then the power was cut to them.

[auburnseeker]

Well it was worth a try and about the easiest test one can perform. 

[handmedownreatta]

i bypassed the relay the windows and sunroof is on last year so  could roll up the windows without a key.the radio goes off when i open a door not with the key as i thought.

Edited March 1, 2019 by handmedownreatta (see edit history)

[CHAS1]

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

[handmedownreatta]

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.

[Ronnie]

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.

[DAVES89]

I bought two Sears tenders. They work great.

[CHAS1]

Looking for Solar for outdoor storage

any thoughts on Solar?

[Ronnie]

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? 

[CHAS1]

Sun Exposure would be several hours each day. It will be placed in front windshield. 3W is the one I am looking at on Amazon. It has good reviews.

These are not designed to be in the elements.

Thanks for your input

Edited March 8, 2019 by CHAS1 (see edit history)

[padgett]

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.

[Ronnie]

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.

[CHAS1]

Would it be best to run alligator clips to battery from solar panel or just plug into cugarette lighter

really appreciate suggestions

thanks

Edited March 8, 2019 by CHAS1 (see edit history)

[Ronnie]

If the cigarette lighter is hot all the time it would probably work. I think it is but I've never used mine. Going directly to the battery would be best.

[CHAS1]

Thanks

[SCOTT's 90's]

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 March 8, 2019 by SCOTT's 90's (see edit history)

[CHAS1]

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

[Reattatude]

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.

[padgett]

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 March 12, 2019 by padgett (see edit history)

[jonlabree]

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.

[padgett]

Those are common in the RV industry particularly to keep the tow car battery from being drained through the hitch connector.