Nokones

The battery is done. It was on borrowed time from 4 years on. Replace the battery with a good quality battery. I believe in Delco batteries for my grocery getters. After, you replace the battery don't forget to re-index the windows.

Also, if you have to keep the battery in a good charge state for a long period of time during the winter, I would invest in a Smart Charger like the Optima Battery Charger. I would go with the 1200 model. It will charge and maintain accordingly for both a wet cell and AGM batteries. The Optima charger will also recover a run down AGM battery whereas, other charger types will only charge the dead AGM battery and that will ruin the battery in a heartbeat.

Yes, the Optima 1200 Charger is expensive at $199.00 but, again it is a smart charger. You get what you pay for.

Oh, one other thing, replace the battery in your FOBS, if you haven't done so already. If the battery in the car has to be replaced, the battery in the FOBS are close behind to be replaced.

NY09C6

There is nothing wrong with keeping that attached. It has a float phase after the bulk charge and can be kept connected indefinitely.

Bruze

Help me out here Al. I only have a basic knowledge of electrics.

A "Four Amp" charger, I always thought, would deliver 4 amps, which the battery would only draw if it was severely discharged. As it becomes more charged, it draws less current. At least that's how I thought the old chargers worked, which had an analog amp meter on them which went down and down as the battery took a charge.

Do I have that right? A nearly-charged battery will not be drawing 4 amps, much like a tiny bulb running on a 20 A. home circuit will not be drawing 20 amps.

johnst783

And consulted the forum for a recommendation on a maintenance Charger...

KB9GKC

ben z

I have a CTEK Multi US 7002, it's an 8-stage charger/maintainer with a separate setting for cold weather, and a power supply setting so it can be left attached when disconnecting or changing the battery and not need to do resets or clear codes. Comes with hardwire pigtail and alligator clip pigtail (quick connectors on each to attach to the unit), but I also have an optional 12V lighter socket connector which I like because on my other car the only way to not have the under-hood light stay on is to trip the latch (then need to remember to release it before closing the hood!).

Bruze

These magnetic snap-on charger connectors are the absolute cat's ***. No hood up, no window down, just snap your charger wire to the connector in your grill and walk away.

NY09C6

Older analog/dumb chargers work exactly as you described. Newer computer controlled chargers generally use constant current during the bulk phase. This allows a smaller charger to charge a battery at the same speed as an older larger unit.

K9KUZ

FWIW - I replace all car batts every 5 years (if they last that long), needed or not.

FortMorganAl

You are correct. That is the way an old style charger and most new ones work. It is also the correct way to get a fast charge. The faster you charge a battery the more damage you will do to it so slowing down the current as it comes up is the correct way if you insist on having a large current to get going fast. The simplest way to do that is to have a constant voltage that is optimum for charging a battery fast (in the 14 volt range) and that's the way it was done at least for the past 50 years. I was just very surprised when Weathertech said they used a constant current. Since I don't have one to measure I don't know if they really do that or that was just some marketing guy's idea.

FortMorganAl

Not the computer controlled ones I'm familiar with. But then again I haven't seen them all because I don't want an all things to all people charger. I have a 12A bulk charger for totally dead batteries that I need today and not tomorrow and I have several maintenance chargers to prevent me from needing the bulk charger. If you use a maintenance charger routinely you should never need the ability to pump lots of current. A $25 maintenance charger and a $10 6A bulk charger will do a better job than a single multi-problem solver device.

AORoads

Lessons, lessons-learning every day. Thanks Dale and Bruze for good questions and good answers.

johnodrake

:agree
Been using maintainers like that for about 10 years and the only issue I ever had was I drove off with it attached and forgot about it and ran over it when I returned!

farmington

Been using my battery tender jr on this same battery every winter for 11 years here in Michigan. Still working just fine.

Bruze

Thanks Al.

Yup, that corresponds to my (admittedly) old-school knowledge that fast charging was not good for batteries, and should be limited to emergency-type situations. I also use .75A tenders, for that reason. (Although I still do not understand the "constant 4A. charging current" on the charger in question. To me, you cannot "push" amps into something; they can only be "pulled" by whatever the load is ).

Also, as I recall, a fast charge only puts a surface charge on, and will not have much depth. All depending, of course, on the lifespan left in the battery before charging.

This all takes me back to my lot-car days, before I had a license. We were constantly screwing around with batteries that were either dead or weak. Charge it, try it, if it still clicked then bang on the terminals with a hammer, rock, or whatever was handy, etc. Sooner or later, all batteries die for good.

I never thought I'd be discussing this stuff at this age. Been driving new vehicles* for 40+ years -- I cannot remember what decade I last had to buy a new battery*.

*excluding my '07 Vette

mikeCsix

I looked up the Weathertech battery charger, it appears to me to be another maintainer with a charging rate of 4amps. Pretty respectable charge rate, but couldn't find anything more technical to determine its effectiveness or safety.

A 4 amp/hr charging rate is still pretty low compared to the overall battery being charged. These batteries are in the neighborhood of 110 amp hours, so percentage wise, 4ah isn't a heck of a lot, nor will it damage a battery or shorten its life. Using a 25 or 50 amp charger might be a different story....

To the OP, did you look at the electrolyte levels in the battery prior to charging? These newer lead acid batteries are vented, but seem to use or evaporate much less water than the older version. Still, the battery should be topped up prior to charging and long term storage. Those covers WILL pry up, and only used distilled water.

The weathertech sounds like it uses a constant 4amps to get to a pre-determined voltage, probably somewhere in the 14v range, then should drop the current down to do the finish charge, then drop again to maintain the charge but once again, couldn't find any technical information to confirm those parameters.

I would connect the Weathertech and using a digital VOM (volt-ohm-meter), monitor the progress of the charging phases being most interested in the final maintenance phase. I've seen maintenance voltages quoted up to 13.8 volts. No THAT will shorten the life of the battery and go through a lot of electrolyte in the process.

HTH

NY09C6

A constant current charger will attempt to raise the voltage to keep the current at the 4amps until the bulk phase is over. It uses the voltage to "push" the current. It will then drop and top off and then float.

Bruze

Aha! I think the light just went on!



Thanks for the clarification.

FortMorganAl

Yep. E=IR. You put 4,000 volts on a 12V battery and I'll guarantee you'll get a lot of amps.

4 Amps is a lot of current for C6 battery that is rated roughly 40 Amp Hours. And you are correct that high current is going to tend to just surface charge the plates. 4 Amps is also going to require a voltage significantly higher than where hydrolysis begins. The reason modern batteries don't seem to lose water like they used to is because battery plate design has improved and we don't charge them like we used to. I remember cars in the 50's had an Ammeter instead of a volt meter and the generator/alternator would continuously run 5-10 amps when the engine was running.

Bruze

Thanks Al. Maybe I'll get this all figured out by the time I get to the nursing home.

- I've kinda wondered why we rarely have to add water anymore. Used to have to check them regularly.

- Yup, I remember cars with ammeters and generators too. At idle the meter would probably go negative, or the "GEN" idiot light would start flickering.