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'72 Opel GT (Sara)
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2,119 Posts
Discussion Starter #1
When I leave my car idle for 3 - 4 days the battery has a tough time turning over the motor and gets pretty weak after just 5 - 6 attempts. So, I was thinking of getting a battery charger. I saw the Deltran brand advertised on My Classic Car on Speed channel. They seem to get good reviews. Anyone have personal experience with this brand?

Thanks,

Matt
 

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Opeler
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175 Posts
Battery Tender

Ive been using the Deltran 'Tender Plus' for a couple winters now,and it keeps the battery in my Opel in good shape all through Michigan winters.
 

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Living in the past
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2,329 Posts
Battery Tender

When I leave my car idle for 3 - 4 days the battery has a tough time turning over the motor and gets pretty weak after just 5 - 6 attempts. So, I was thinking of getting a battery charger. I saw the Deltran brand advertised on My Classic Car on Speed channel. They seem to get good reviews. Anyone have personal experience with this brand?

Thanks,

Matt
The Battery Tender will maintain your battery at full charge, but, if it goes down in three or four days you have a problem with your battery or connections, or cables. It should stay up longer than that if everything is proper. Of course if the car is parked outside in cold weather the battery does not like that and will give you a problem.
 

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Trouble Maker
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1,523 Posts
What AMP rating do you have on your GT? Was it new/reman when Keith restored your car or was it reused from before th resto?
 

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UFOpel Investigator
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3,472 Posts
The battery tenders work great if you don't do what I just did.
Went to start the Manta this morning after it had sat for about a week
on the tender and it was about flat. Looking around to see if something
was amiss, I discovered I had accidently bumped the 6V/12V switch on the
tender to 6V. Doh! :banghead:
Looks like the battery will be okay at least. :ugh:
Btw. Both my tenders are Sear Craftsman.
 

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Old Opeler
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5,564 Posts
Winter Lockdown ...

If you are laying up your GT for the winter it pays to remove the battery and take it into the laundry or warm part of the car shed as batteries hate the cold. Hook it up to a battery tender and check the fluid level from time to time and your battery should be as good as it was when you started the Winter storage.

BTW: A battery 'makes' electricity with a chemical reaction - the colder it is the slower that reaction takes place - thus lowering the output of even a 'good' battery at low temperatures.
 

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When I leave my car idle for 3 - 4 days the battery has a tough time turning over the motor and gets pretty weak after just 5 - 6 attempts.

Matt
Sorry Matt that I had to quote you.
Theres something wrong. I can let my GT sit for over a week. The only draw is a clock and a radio memory. And this is with a very small battery and it will spin over for over 3 minutes. One day I'll fix the leaking acc. pump.
Off the top maybe a shorted battery
or a small draw
or bad diodes in the alt.
Dan
 

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'72 Opel GT (Sara)
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2,119 Posts
Discussion Starter #8 (Edited)
What AMP rating do you have on your GT? Was it new/reman when Keith restored your car or was it reused from before th resto?
I have the 45 amp alternator but can't recall if it was new or re-manufactured. On a day to day basis I don't have any issue though. The AMP gauge shows it is charging the battery and the car starts right up on the very first crank day in and day out. Only when the car sits for several days in colder weather do I have this issue.

Today, for example, I went to start the car this morning after it sat for almost 5 days. The car turned over several times but, after the fifth attempt or so, the battery clearly didn't have enough power left and the car wasn't going to start no matter what. When I got home from work and the car had sat some more, it started right up on the first try. My theory is that the battery is losing some charge when it sits for several days in the colder temps and then doesn't have enough power to turn the car over the few extra times it needs after it has sat. The car starts many hours later presumably because the battery has gained back some charge and the car only needs one crank because it was "primed" in the morning.

Anyway, my theory is that the battery tender would keep the battery at full charge and therefore have what it needs to start the car after being parked for a period of several days (i.e, the battery could handle the few extra cranks required). Then again, maybe I am just flooding the carb when it needs more than one crank to start up :confused:.
 

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'72 Opel GT (Sara)
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2,119 Posts
Discussion Starter #9
Sorry Matt that I had to quote you.
Theres something wrong. I can let my GT sit for over a week. The only draw is a clock and a radio memory. And this is with a very small battery and it will spin over for over 3 minutes. One day I'll fix the leaking acc. pump.
Off the top maybe a shorted battery
or a small draw
or bad diodes in the alt.
Dan
Hmmm, well maybe so. I was posting when you posted this but note that this is a problem maybe a couple times a year. I assume if I had a bad alternator or any other major issue, it would be more consistent :confused:. I do have a rather complicated radio set-up with the XM Radio. I have an in-dash head unit, a separate XM tuner, an XM "adapter" module (takes the output of the XM tuner as an input and then sends the signals and data to the in-dash head unit), and an amp. Maybe a check of the connections is in order...

Matt
 

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Trouble Maker
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Sometimes Alarm systems and Stereos can make a draw like that.
 

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I have a similar problem on my monza. It takes a lot of cranking to get it started. That's because the fuel has evaporated from the carb. Your problem could be cured by using an electric fuel pump, that has a prime switch in the elctrical circuit. The monza has an electrical pump in the fuel tank, but only works under the "start" cycle, or when the oil pressure light is off with the key in the "run" position. So it takes a while for the fuel to get to the carb from the tank. To test my premise, pull the air cleaner off the carb, hold the choke open and manually open the throttle to see if there is fuel squirting in the venturi from the accelerator pump.
 

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Matt I have several vehicles for the biz that sometimes sit for days in the cold and always have used the Battery Tender Plus...simple out of the way 2-prong plug in and they crank right up...seems to keep the battery "topped off" when we go to crank them...North GA winters are tough on the batteries but the "Tenders" are a mainstay in my shop...the Goldwing is always on one

SteveG
 

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The "vat 40" can and will load test a battery/alt.
The parasitic draw is another problem.
For that we'll need the battery group of the one your using.
 

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'72 Opel GT (Sara)
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2,119 Posts
Discussion Starter #14
Thanks all for the feedback on the Deltran battery tender and the other things to look into - which I will. What I think I will do is buy the Deltran Plus unit (on eBay right now for $43) and then test this out over the Christmas break (which is the next time the GT will sit for a prolonged period - I can't go that long not driving the car for no reason :D). I'll put the car on the battery tender and see what happens when I go to start her back up. That should be a good test.

Matt
 

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'72 Opel GT (Sara)
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2,119 Posts
Discussion Starter #15
The "vat 40" can and will load test a battery/alt.
The parasitic draw is another problem.
For that we'll need the battery group of the one your using.
I'm not sure what "vat 40" is... I have a Napa Power 65 (model 6026R) battery.
 

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8,178 Posts
I assume if I had a bad alternator or any other major issue, it would be more consistent :confused:. Matt
Keith got the core from me and had it rebuilt locally. I think anything he installs like that he takes to a local shop and has them go through it. The battery should hold up for several weeks without any problems. Are all of your radio components switching off when you turn the key off. :ponder:

Harold
 

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'72 Opel GT (Sara)
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2,119 Posts
Discussion Starter #17
Keith got the core from me and had it rebuilt locally. I think anything he installs like that he takes to a local shop and has them go through it. The battery should hold up for several weeks without any problems. Are all of your radio components switching off when you turn the key off. :ponder:

Harold
The in-dash unit draws a small amount of current to maintain settings and the clock. I have the clock display set to "auto shut off" after 30 seconds. The amp uses a "remote wake up" wire that is connected to a switched power source and I have verified that it only runs when the car is started and does shut off when the car is turned off (based on its power LED). As far as the other XM components, I can't recall now how those are connected - I will have to check. They are hidden in the passenger footwell under the carpet and so I haven't looked at them in over a year.

Based on the replies here, it sounds like I do have a small draw that is affecting the battery and also am probably coming back to a car with a carb that doesn't have any fuel in it. The battery doesn't have enough power to get the engine turned over enough times to get fuel into the carb and start the car. The battery tender may be a band aid.
 

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Super Moderator
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The battery doesn't have enough power to get the engine turned over enough times to get fuel into the carb and start the car. The battery tender may be a band aid.
Matt, Keith worked pretty hard on installing your "little" radio system. My money is on a battery going bad. A simple voltage test isn't good enough to determine if the battery is bad. I've had two that passed the voltage test but failed the amp test badly. There are any number of auto parts places that will test it for free, some will even test it in the car.


Harold
 

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No....its not a Buick....
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1,545 Posts
Depending on how old the battery is....I'm leaning in that direction as to the trouble. I also have a battery disconect switch of sorts in place to prevent any draw while the car is in storage. It was cheap....like 6.00 off e-bay....
Probably not good for the radio memory but a good thing to have in an emergency.
Joe
 
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