Squarebirds, Rocketbirds, and Fifties/Sixties Ford Discussion Forum

Squarebirds, Rocketbirds, and Fifties/Sixties Ford Discussion Forum (http://squarebirds.org/vbulletin/index.php)
-   Ford Electrical Problems ~ General Technical Discussion (http://squarebirds.org/vbulletin/forumdisplay.php?f=78)
-   -   AGM battery - NOT for classic cars. (http://squarebirds.org/vbulletin/showthread.php?t=22354)

simplyconnected 01-15-2018 07:23 PM

AGM battery - NOT for classic cars.
 
Robin's 2010 Escape needs a battery. Her OEM battery lasted seven years!

Upon removal of the battery and its covers, the Motorcraft label revealed 'AGM' which means, Absorbed Glass Mat design. This is different from conventional lead acid (also called, 'flooded cell') batteries. The car's charging system is also designed for this battery, so don't use a standard bench or float battery charger. Unattended, it will overcharge and ruin the AGM battery. Also, don't use it in your classic car.

Expect this from AGM batteries:
•Product life lasts up to two times longer (ours lasted 7 yrs)
•Extremely heat and cold tolerant (great in Texas or Calgary)
•Ideal for vehicles equipped with lots of electronics (heated seats, navigation system, parking assist)
•Durable - Outstanding vibration resistance
•Safer - No free-flowing electrolyte or spill hazard

Wonderful, right? Maybe, if these rules are folllowed...
Charge AGM batteries at a constant current rate of no more than 10 times I20 to a voltage of 14.1V (example; For C20=100Ahr, the max charge current is 10x5A or 50A). Many 'bench chargers' peak at 15-volts which will kill this battery.

Temperature plays a big role here:
Charging voltages are based on a temperature of 77F (25C). For average operating temperatures below this range (colder than) the maximum voltage set point should be compensated with an increase at a rate of 0.018 volts / F (0.032 volts/ C.) For average operating temperatures above this range (warmer than) the maximum voltage set point should be compensated with a decrease at a rate of 0.018 volts / F (0.03 volts/ C.) Example: at 65F and 14.2 volt set point Corrected Voltage = 14.2 - ((77-65) x (0.018)) = 13.82 volts.

Modern car charging systems are designed for this compensation. Classic car charging systems are NOT. So in a nut shell, your classic car was designed to charge a standard lead-acid battery.

As a rule of thumb, AGM batteries should be use to replace OEM AGM batteries. But cars with AGM charging systems work just fine on standard lead-acid batteries so they are backward compatible. - Dave

Deanj 01-16-2018 09:36 AM

I like battery stories.

I had a 2006 Dodge Charger RT OEM low maintenance battery last 7 years. I replaced it only because Summer was approaching. My 2000 Corvette battery lasted 7 years. However, my wife's 2013 Charger RT battery has drained twice in the last 11 months when sitting idle for 4 days.

I'm guessing the latter is a problem of proximity. I theorize the key fob is about 6 feet from the car, and therefore remains in communication with its computer. The car never really goes into sleep mode... I think.

Dean

DKheld 01-17-2018 09:15 AM

Great info Dave - I've heard more than one person complain that the AGM batts aren't any better than standard batteries. That coming from folks who have installed them in their classic car.

Our 08 Escape battery lasted about 6 years. Replaced it with one from Advance Auto (their Silver line - mid range). I've had good luck with these - usually get 7-8 years out of them.

Dean - sounds like you have a current drain. Not sure about the remote thing - my remote is 20 yards away from my Dodge truck but it's a 2012 so may not have all the "communication" between the truck and remote that you have on the Charger.

Do you have a way to measure the switch off current drain? should be less than 100 milli-amps but 60-80 milli-amps should be great. You can even measure it with one of the cheap-o or free meters from Harbor Freight - just might have to disconnect the under the hood light while checking it. Disconnect the one of the battery terminals and put the meter in line in the current mode. Probably can google it and find a good description on how to connect it.

While you're measuring the current if you open a door and the interior light will come on and most likely blow the fuse in the cheap-o meters so be sure and only measure with everything off.

This is a clamp on version - was measuring current output on the Tbird generator so that's much higher reading 24.7 Amps.



Also possible that your battery has a shorted cell - it will charge and work under most conditions but any extended draws (even small ones) will make it loose capacity quickly.

Just some ideas - Eric

edit - looks like a decent article about finding "leaks"
http://www.popularmechanics.com/cars...attery-drains/

Deanj 01-17-2018 10:17 AM

Quote:

Originally Posted by DKheld (Post 113199)

Dean - sounds like you have a current drain. Not sure about the remote thing - my remote is 20 yards away from my Dodge truck but it's a 2012 so may not have all the "communication" between the truck and remote that you have on the Charger.

Do you have a way to measure the switch off current drain? should be less than 100 milli-amps but 60-80 milli-amps should be great. You can even measure it with one of the cheap-o or free meters from Harbor Freight - just might have to disconnect the under the hood light while checking it. Disconnect the one of the battery terminals and put the meter in line in the current mode. Probably can google it and find a good description on how to connect it.

While you're measuring the current if you open a door and the interior light will come on and most likely blow the fuse in the cheap-o meters so be sure and only measure with everything off.

This is a clamp on version - was measuring current output on the Tbird generator so that's much higher reading 24.7 Amps.



Also possible that your battery has a shorted cell - it will charge and work under most conditions but any extended draws (even small ones) will make it loose capacity quickly.

Just some ideas - Eric

edit - looks like a decent article about finding "leaks"
http://www.popularmechanics.com/cars...attery-drains/

Thanks Eric. I'll hook up my multi-meter this weekend as you suggest. If there's a leak, I wouldn't know where to begin to trace it down. If no leak, I'll truck down to the local "Bull Dog Battery" to test the battery. The funny thing was the last time this happened, the extra key fob battery kept 6 feet from the car was shot, also.

I bought my T-Bird battery at this same place and was offered the choice to skip their logo on the side of their battery. That came in handy so I could place the Power Punch decal that no one sees on the new battery.

Dean

Deanj 01-22-2018 10:50 AM

Tested the 2013 Charger RT Road & Track battery and it read 12.5V. Tested the battery draw while the car was in sleep mode and it read 11 milliamps, which is very acceptable.

I concluded a 4 1/2 year old battery, while still pretty good, can't take 4 days of checking systems readiness. A former Honda and Pontiac service tech recommended locking a keyless start car over moving the key fob proximity to Timbuktu. This places the car in sleep mode quickly. It seems to explain why this car can stand 5 days in an airport parking garage locked vs. 4 days unlocked in my garage.

How much does an original Squarebird clock draw?

Dean

Frango100 01-26-2018 02:05 PM

The original squarebird clock is an electrical/mechanical wind clock. It doesnt draw a constant current. As soon as power is applied to the clock, it will wind a spring in a fraction of a second, where after it opens its electrical contact. The spring will move the clock for about one minute and 15 seconds, where after the contact closes again and the spring is wound again. etc etc etc.
The clocks fuse is 1 Amps, so expect a current draw of 600 m Amps or so. But as said, its only a current draw for a very short time, which repeats itself each one minute and 15 seconds.

Deanj 01-26-2018 02:28 PM

Thanks Frank. I recall reading somewhere that's when the current responds to these clocks. The 600 m amps is drawn for a couple seconds and then it's dormant for another 75 seconds. I wonder how a constant draw of 11 m amps compares with 600 m amps per 75 seconds?

Dean

Frango100 01-27-2018 11:32 AM

My electrical knowledge is not that good, but i think that 600 m Amp in 75 seconds would be 8 m Amp per second (600 divided by 75).

simplyconnected 01-27-2018 02:03 PM

You guys know how a relay works. When energized, the clapper immediately draws-in magnetically. Ford clocks are identical BUT as soon as the clock 'clapper' draws up the coil contacts break connection. So, here we have the coil wire, fed by a normally closed relay contact.

How long does this take? It's so fast that six volt clocks work equally as well on 12-volt systems because the contacts open even sooner. The windings don't have enough time to burn out because they are only used for a fraction of a second.

The purpose of the 'clapper' (which is really an armature) is to wind the clock spring. Ford attached the electrical contacts to the clock spring. The contacts close when the spring depletes. As noted, the spring takes ~75 seconds to deplete before the next 'bump'.

Ok so, how many milliamps per time unit? This is tough because inrush current is huge but only for about 1/10th of a second every 75" or about 1,150 times per day. This looks like a lot but these intervals are intermittent.

Current drain would be worse if the drain was constant because lead-acid batteries partially recover during 'rest time'. Did you ever crank the starter until the battery was so dead that the starter solenoid would only click, only to try later and find the battery has more cranking power? That is the type of intermittent drain and recovery I'm referring to.

A healthy battery should last a few weeks of idle time before the clock affects cranking power. - Dave

Deanj 01-28-2018 11:11 AM

Quote:

Originally Posted by simplyconnected (Post 113324)
...
Current drain would be worse if the drain was constant because lead-acid batteries partially recover during 'rest time'. Did you ever crank the starter until the battery was so dead that the starter solenoid would only click, only to try later and find the battery has more cranking power? That is the type of intermittent drain and recovery I'm referring to.

A healthy battery should last a few weeks of idle time before the clock affects cranking power. - Dave

Thanks Dave. Very interesting, and I would assume a constant draw when changed to a quartz replica clock?

That antique car "click" is funny because the 2013 Charger RT lit up the instrument panel with lights and operated the wipers one swipe when the battery became drained. Even the power windows and lights worked, but not the power seats. The Check Engine light remains on because a couple throttle sensor codes are set when there isn't sufficient battery power. Lucky I have an OBDII tester that will clear this once the battery is re-charged.

As I said, we lock the car now so it will enter "sleep mode".

Dean


All times are GMT -4. The time now is 10:55 PM.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Any submissions to this site and any post on this site becomes property of Squarebirds.org . The webmasters reserve the right to edit and modify any submissions to this site. All material on this is site is copyrighted by the Squarebirds.org. Reproduction by any means other than for personal use is strictly prohibited. Permission to use material on this site can be obtained by contacting the webmasters. Copyright 2002-2016 by Squarebirds.org.