Please educate me about car batteries.

[TechnoLoGs]

I want to know it all. Please tell me about resting voltages. Surface charge. States of charge. Discharge. Why shaking a battery is bad, another advice I had to un-learn, and which probably helped me kill my old battery with a shorted cell. When the poles reverse. What a soft cell is. Continuity. If side posts are better than top post. When batteries have both, if you can use either or. What a good voltage is, for resting voltage. How a smart charger works. If I should get a super-duper whizbang 7800 smart charger, etc. If a 3300 desulfates. if CTEK or NOCO is best. If the Power Pulse desulfator I bought that will hook onto the top and stay in the truck is any good. All of it.

Backstory: I purchased a new battery, a few days ago. Let it run for about 20 minutes with high load, and no alternator, as per my wiring and charging woes, which should disappear after I connect back that ring terminal I left off, and improve all grounds. Battery had 14.7V when the car was running, after being discharged for 20 minutes (run with no alternator and loads of fan and radio and headlights on. Did this to deplete a surface charge.) I left it on my smart charger for two days straight, and it always levels out to 12.9V. I sometimes hear people say the resting voltage is supposed to be 13.2V, at 2.2V for each cell; then EricTheCarGuy says 12.6V for when it is in a vehicle.

The battery is 5 days old, it has spent about 20 minutes being discharged intentionally to break a surface charge, and it has spent about an hour being used with the alternator on, and a certain alternator wire disconnected. It is a NAPA, with 540CCA. Appears sealed.

Please educate me about battery behavior. I do not want to run down and destroy this one. And so far, it appears like the alternator is wired up correctly and that won't happen, so please educate me about the heart of the system, the battery.

 

[cat843]

Your battery has had a rough start so it seems. But its under warranty, so if you have trashed it you can get another. Surface charge lasts 24 hours, so if you charge up a battery fully with a decent AC charger and let it sit 24 hours the surface charge will be gone. Or 5 minutes of headlights.

The chargers that have a desulfation circuit probably do work in some cases, the theory is there but don't expect that function to bring back a battery from the grave to make it as good as new.

Also you need an accurate meter to measure battery voltage to determine % of charge. You are better off with a carbon pile load tester. Dial it to 50% CCA, wait till it beeps (15 seconds) and quickly read the compensated voltage and you are done. That is the best test available assuming the battery is 100% charged, better than a Midtronics tester. The value of a Midtronics tester is a shop/store can test the battery when its not fully charged and tell you if its good or bad.

 

[EricG]

Here you go!

http://batteryuniversity.com/

 

[SHOZ]

Keep the battery charged and sulfation is not an issue.
Surface charge is nothing to worry about.

 

[eljefino]

We used to have a user GearHeadTool on here who loved his CTEK.

 

[Stanley Rockafeller]

Originally Posted By: eljefino
We used to have a user GearHeadTool on here who loved his CTEK.


I miss him, what happened to him?

 

[stevejones]

You're overthinking this one.

I've bought many batteries, as I keep my vehicles 10+ years and have four of them in the rotation.

Buy name brand, throw on the charger overnight, install next day, return old battery. Rinse & repeat every 5 years or so.

 

[supton]

So far I've had new batteries start the car right up. I do the core return five minutes later (or twenty minutes later if I drive it a bit to bring the charge up). Seven or so years on a battery.

 

[1 FMF]

http://www.batteryfaq.org/

battery 100% state of charge is 12.65 volts with the battery disconnected from everything with the battery electrolyte at 80°F. if the battery is colder then the voltage will be lower, around 12.55 volts at 32°F. whether you get to within a tenth of that voltage will greatly depend on the accuracy of your digital multimeter. An AGM battery such as an optima or diehard platinum which cost about twice as much as the typical wet lead-acid battery will have a slightly higher open-circuit voltage of 12.80 volts at 80°F.

when you buy a new battery, always look for the manufacture date sticker on the battery and choose the newest. the longer a new battery sits on the store shelf self-discharging the worst off you will be. i think they are suppose to rotate stock and not keep anything older than so many months, less than 6 months old is best. buying batteries at service centers where a tech or salesman gets you the battery and you never see it before it's installed is the worse, they will screw you. You should put your brand new battery on a smart charger before installing it into the vehicle and charge minimum of 8 hours to guarantee it gets to 100% state of charge. otherwise you're installing the new battery in a discharged state and there's no guarantee the car will charge it to 100%, that will depend on your driving conditions.

Quote:
The battery is 5 days old, it has spent about 20 minutes being discharged intentionally to break a surface charge, and it has spent about an hour being used with the alternator on, and a certain alternator wire disconnected. It is a NAPA, with 540CCA. Appears sealed.


i don't know wth you were trying to do there, but don't do that.
i prefer the battery tender chargers or the batteryminder by VDC. the batteryminder will have the pulse thing is around $60 mail order. be careful buying a "smart" charger from walmart or other local store, many are falsely advertised and if you don't use it correctly you can overcharge a battery or improperly charge a battery.

i would not use that powerpulse desulfator that connects to the battery while installed in the car and not while the engine is running. it's not a charger and most likely does nothing. the pulse thing for desulfation is not a fact either, and deltran who makes the battertender chargers to my knowledge has never made a pulse type charger advertised to break up sulfation. the pulse technology at the least a gimmick to offer a selling point of one charger over another. I only recommend the batteryminder because i've owned one for over 10 years and it properly charges and floats batteries and was cheaper than a deltran. and i had the pleasure of having a battery backup system at work serviced which uses 36 car batteries, the charging system on that nor on any UPS system uses any type of pulse technology like what's advertised for automotive world. if it were so great then the battery industry as a whole would be using it, the cost of the ups service with battery replacement cost more than your vehicle.

if you drive your vehicle every day or close to it, then charge the new battery to 100% before installing into vehicle then don't f with it other than keeping the terminals clean. if the vehicle will sit for more than 1-2 weeks then put a smart charger on it that will float charge and maintain the battery at 100% to counter the self-discharge and slight draw of being in the vehicle. And a smart charger is a slang term which means you can hook the charger up to a battery and leave it on forever and there is nothing you can do that will harm the battery. chargers that have knobs and switches that you can choose charging rates or that say trickle charge stay away from