Got to love simple, low-content cars

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JHZR2

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Drove my 240D last on Thanksgiving. Car has sat with no charger on the battery since then. Not the coldest winter, but put my HF tester on the battery before starting up last night (was expecting the battery to be low, so brought my spare battery and jumper cables). Now this battery is from 2005, mind you. A 100Ah Mercedes-Benz, white case group 49 replacement battery: So what did I see? That's right, full voltage and ready for great performance (nice low resistance). The only load on the car is a small quartz clock in the instrument cluster. Interestingly, at 40F, I actually had better CCA than nameplate. Now, the nameplate amps are euro-rated, so may be different than US CCA values. Modern cars can barely sit for a few weeks without a weak battery.
 
My Peugeot is this way, too. The clock died, so even that's gone. I did put a modern Clarion radio in the car. It's the only load when the key is off. My 1998 Dodge van is almost like that, but it keeps airbag and PCM memory circuits live as well as the radio. It started after sitting for 2.5 months outdoors in Wisconsin winter while it was waiting for me to fly back and retrieve it. My 2005 Park Avenue runs the battery out after about ten days. Since I often go for a week without driving it, I keep it on a charger all the time. During the summer, a solar Battery Tender does the job, but the during the winter I need to use a regular AC Battery Tender.
 
Our Fit can kill its battery after a week of sitting. Not sure about our Cruze yet. It's got more delayed-power stuff than I can reasonably list. At least it's a common battery that's easy to get at when it's time to replace.
 
MB group 49 white case battery is very good. I replaced the OEM battery in my '00 E430 in Dec-2004 with MB white case battery for $140-150, it lasted until last April. It may be okay if my wife didn't forget to turn off the headlight several times for 8-9 hours each time. I would replace with MB battery if the price didn't shoot up to $219, I replaced with Motorcraft BXT49 for less than half at $93.
 
Mercedes batteries are amazing, my friends finally gave up the ghost in his 1995 S600. 17 years out of an OE battery is pretty good! I know of a number that lasted 10-15+ years. Around here they seem to go 10-12 years average, and are 110-130 at the dealer depending on where you go. They are made in Spain and not by Johnson Controls or Exide.
 
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My mom's 2005 BMW 330ci is about as electrically complex as you can get. The car often sits for weeks at a time and the battery has never gone dead. In fact, the car is 7 years old and it still has the factory original OEM battery.
 
^ The issue isn't necessarily how much electronic [censored] is in the car, but how good it is about powering down everything that doesn't absolutely need power. The longest I've personally let my Jeep sit is 5 days, no issues there. I've seen similar ones sit for 2 weeks though, and fire right up without a hint of slow cranking.
 
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The main point here isnt the ability to turn over the engine. A battery at fairly low SOC can do that even in the cold. What suprised me was that the battery was at 100% SOC. I had expected self discharge, some capacity loss, etc. Didnt see any of that. 12.73V is 100% SOC.
 
The W123 were amazing, no wonder most German taxis were these models through the 80's with many still in service in the early 2000's My 1980 200D had the OEM battery in it when i got the car from my grandmother over a decade later, it was MB labeled but made by HOPPECKE according to the MB parts dept. I wondered if they still make the MB batteries but see they sold out to Johnson controls in 2001. Maybe Varta now? http://www.hoppecke.com/
 
While a batteries capacity is diminished by cold temperature the batteries self discharge/internal losses are significantly slower when stored in colder temperatures. It's two different things. If you measured the specific gravity and temperature compensated,if measuring when was still cold, it probably lost very little. And that 100ah rating is completely different from CCA. I'm not sure how Mercedes rates their batteries but that is probably the "reserve capacity" which is when a battery is the amp hour capacity of a battery when discharges to 1.75 volts per call @25AH. I'm not sure the %of the rated capacity it would need to meet in order to still be considered viable/serviceable. With the Industrial stuff I deal with it need to be %80 of rated capacity or higher. I would be surprised if it's not the same. So in this case it need to run 3.2 hours and have pulled 80 amps out of it with the voltage remaining at 1.75 volts per cell,10.5 volts per cell here, or higher. I don't have any experience with frequency testers but it seem to me they would give a reasonable approximation if the battery is in good shape internally, but a load is test is IMO the only way to get a truly accurate idea of what is going on with a lead acid battery. I could be wrong but I believe they were developed by the stationary/ups guy who could not pull cells or strings of cells(banks)out of service long enough for proper testing. An example of it's limitations would be how noted above that it is now at a higher CCA then rated for. Not possible, it's and error in the tester or algorithm. Not trying to bash your gear, just trying to point out it's limitations. I wouldn't mind having one myself. If your not actually measuring the current a battery is capable of producing, CCA, or otherwise then your relying on a guesstimate, albeit I'm sure a fairly accurate one, of an algorithm. Which was probably designed to alert you that further testing is needed.
 
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I didnt correlate CCA to Ah. The battery was marked in cranking amps, but may have been evaluated differently. I get self discharge and kinetics, I still would have expected more given recent measurements on other batteries in my fleet. Since I know impedance and voltage, I very accurately know power and heat generation characteristics.
 
12.73 might not be fully charged for that battery. They can all vary a little. I Had some JC everstarts rv/marine/dual purpose that were 12.83 fully charged and rested. Now I've got 2 new Crown Deep cycles that at full charge, when fully rested is 12.6 volts. Put a charger on it overnight, let it rest for several hours then test the voltage. Regardless, those are good readings for a battery that has sat for a while.
 
Originally Posted By: JHZR2
I didnt correlate CCA to Ah. The battery was marked in cranking amps, but may have been evaluated differently. I get self discharge and kinetics, I still would have expected more given recent measurements on other batteries in my fleet. Since I know impedance and voltage, I very accurately know power and heat generation characteristics.
Didn't mean come off snarky or intend to bash you or your gear. I was just offering some insight into what and why you were seeing it.
 
Probably a DEKA (DECA?), depends on when manufactured. Personal experience: just (as in "last week") replaced the MB "white" Group 49 battery in the 1991 420SEL. It was the battery in the car when we bought it in 2001. Battery dated to an 8/1999 installation, so... 12 year, 5 month service life. I can remember removing it and adding distilled water one time, followed by an overnight 6 amp charge and about an hour on a Deltran Battery Tender Jr., until the green light came on. Tested "low but OK" at the auto parts store. Had been experiencing an intermittant cold/hard start and figured it was probably time to replace it. Boy! That's a really heavy battery! Cheers! p.s. Just imagine what the market would be for a simple version of the woefully over-equipped, overly complex vehicles that are being crammed down the throats of American consumers, all in the name of so-called "safety" and conservation? An a/c vs. a 4-zone climate control. A place to install what the new owner wanted vs. a $4000 XYZ infotainment system. etc., ad nauseam
 
Originally Posted By: 3311
Originally Posted By: JHZR2
I didnt correlate CCA to Ah. The battery was marked in cranking amps, but may have been evaluated differently. I get self discharge and kinetics, I still would have expected more given recent measurements on other batteries in my fleet. Since I know impedance and voltage, I very accurately know power and heat generation characteristics.
Didn't mean come off snarky or intend to bash you or your gear. I was just offering some insight into what and why you were seeing it.
Not at all. Your post was great. Im just familiar enough with electrochemistry and energy storage, as well as seeing changes in the field measuring my own vehicles and batteries integrated into other systems... The result suprised me. Didnt take your post badly at all. Great content!
 
Originally Posted By: wrcsixeight
12.73 might not be fully charged for that battery. They can all vary a little. I Had some JC everstarts rv/marine/dual purpose that were 12.83 fully charged and rested. Now I've got 2 new Crown Deep cycles that at full charge, when fully rested is 12.6 volts. Put a charger on it overnight, let it rest for several hours then test the voltage. Regardless, those are good readings for a battery that has sat for a while.
Agreed. Deep cycle and certain dopants beyond the Pb system can create other voltages. Also electrolyte schemes (e.g. gel cells) can vary that a bit too. But this is a plain flooded battery, even with fill caps.
 
Originally Posted By: JHZR2
Originally Posted By: 3311
Originally Posted By: JHZR2
I didnt correlate CCA to Ah. The battery was marked in cranking amps, but may have been evaluated differently. I get self discharge and kinetics, I still would have expected more given recent measurements on other batteries in my fleet. Since I know impedance and voltage, I very accurately know power and heat generation characteristics.
Didn't mean come off snarky or intend to bash you or your gear. I was just offering some insight into what and why you were seeing it.
Not at all. Your post was great. Im just familiar enough with electrochemistry and energy storage, as well as seeing changes in the field measuring my own vehicles and batteries integrated into other systems... The result suprised me. Didnt take your post badly at all. Great content!
Glad to hear!:)
 
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