Charging question

[Torched10]

This may be silly question but I need to ask.ive been,pretty much housebound,and wanted to check battery on,my 19 gt.so start the car and see voltage is 13.9
I figure when, had got my battery would be charged by letting it run at idle for an hour,just like if do in my old gtos.wrong,.after 2 --30 minutes idle runs battery its at 13,5v,so then say I'll go for an hour drive on highway and keep rpm around 4k.well did that,still 13.5v. So is there an optimum rpm while driving the car that would allow alternator to charge battery was 4k too high.car only has 2k miles and was driving it once a week,and voltage on gauges would always be around 14.thanks for any advice as always.

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[LxMike]

On a 2012 Honda Civic I had before my mustang they have an Electric Load Detector that senses when there is a heavy load on the battery and will adjust alternator output accordingly. I freaked out when I was using my scanguage and it shows my battery was at 12.x volts. Then I turn my headlights on and it jumped to 14.0-14.1.

 

[ice445]

Smart charging logic does what it wants

 

[frank s]

More InterWebz information/Wisdom.

https://www.tetongravity.com/forums...ng-a-Drive-for-Alternator-to-Recharge-Battery

 

[RalphK]

13.5v is more than a full charge for lead acid batteries. Charging voltage can be all over the place.

 

[Elp_jc]

I have the voltage gauge activated on my Bullitt, and it only shows 12.0V. What the heck? And the battery is pathetically insufficient for a V8; it's only 330 CCAs. My 3.5EB truck was 760. Heck, my wife's 4 banger is also 760. But I'm suspecting I need to reset the BMS or something, since 12.0V is not even charging the battery. That gauge is supposed to tell us alternator current, not just battery charge, right? Will hook up my multimeter next time I use it to see how much the alternator is spewing; it better be at least 13.xx. Car has only 300 miles, but sat at dealer for months, so battery is toast. Tried 2 different desulfating chargers, and neither worked. It's permanently sulfated by now.

 

[Torched10]

I have the voltage gauge activated on my Bullitt, and it only shows 12.0V. What the heck? And the battery is pathetically insufficient for a V8; it's only 330 CCAs. My 3.5EB truck was 760. Heck, my wife's 4 banger is also 760. But I'm suspecting I need to reset the BMS or something, since 12.0V is not even charging the battery. That gauge is supposed to tell us alternator current, not just battery charge, right? Will hook up my multimeter next time I use it to see how much the alternator is spewing; it better be at least 13.xx. Car has only 300 miles, but sat at dealer for months, so battery is toast. Tried 2 different desulfating chargers, and neither worked. It's permanently sulfated by now.

Continued my charging experiment today.start the car up.and detail gauge is 14v.,put it in drive its 13v,yesterday was 13.5. Drive along and noticed when I took foot off throttle at any speed,voltage would hit
14. Hit throttle. Then 13v
Turned car off and started it again 14,but throttle in neutral 13. So is this the way it's supposed to work.if you guys are just driving along dies voltage sit around 13v.hate to bring to dealer,even though it's covered.ill try again in couple days and if running voltage drops again,figure something is amiss.thanks for any input

 

[Elp_jc]

Your car is perfectly fine, brother. I'm more worried about mine, only showing 12.0V on the mini digital gauge (need to check with a multimeter when I use it again). Remember Ford has an 'intelligent' charging cycle managed by the BMS (battery management system). It only charges the battery when necessary, to minimize engine load, and therefore, fuel economy.

 

[Torched10]

Your car is perfectly fine, brother. I'm more worried about mine, only showing 12.0V on the mini digital gauge (need to check with a multimeter when I use it again). Remember Ford has an 'intelligent' charging cycle managed by the BMS (battery management system). It only charges the battery when necessary, to minimize engine load, and therefore, fuel economy.

Thanks for reassurance.ill let it go.my pp1 401a shows digital readingss for everything,including voltage,as well as gauge cluster.thats the problem with being an engineer,always looking for a problem to solve.

 

[Elp_jc]

Just took my car for a ride after disabling the fake engine sound, and confirmed my alternator is working correctly. Upon firing up the engine, checked with my multimeter, and it was reading 14.3V. Went inside right away, and the gauges were also showing 14.3, so all is well. As mentioned, the algorithm changes the charging to minimize engine load/fuel consumption. Since my battery is always fully charged, it shows 12V when going, but jumps to 13.xx or even 14 when coasting. Makes sense, so all is well now .

 

[OLdchuck]

Torched, I hear you on being concerned and wanting to know how the system works. Things I can not figure out cause me to lose sleep. I appreciate the informed members here shedding light on the Mustang's charging system.
I am curious why Ford chose to use such a low CCA battery on a V8 such as the Coyote. I guess it is like hood struts that if you want better than you will change them. Motorcycles do this with the seats. You can have a 20 grand + bike with a terrible seat as they know they can save money in manufacturing as the customer will change it out if they want.. I guess everything is built to a price point..

 

[Torched10]

Just took my car for a ride after disabling the fake engine sound, and confirmed my alternator is working correctly. Upon firing up the engine, checked with my multimeter, and it was reading 14.3V. Went inside right away, and the gauges were also showing 14.3, so all is well. As mentioned, the algorithm changes the charging to minimize engine load/fuel consumption. Since my battery is always fully charged, it shows 12V when going, but jumps to 13.xx or even 14 when coasting. Makes sense, so all is well now .

Elp. thanks alot.good,to know your voltage reading a,now I'm really reassured

 

[GregP27]

Battery charging is not a simple subject. You could have a wet-cell (flooded) lead-acid battery, a valve-regulated lead-acid battery (absorbed glass mat battery (AGM), gel cell), deep-cycle battery, or a lithium-ion battery (electric or hybrid cars). There are others, too.


Most are SLI (starting, lighting, ignition) batteries. Like the name implies, these batteries not only help start your car, but also provide power to your ignition, lights, radio and more. SLIs have a shallow charge cycle (the time it takes to run down the battery and charge it back up) and can only deliver power in short bursts of time (e.g. the amount of time it takes to start your car). You may also have a deep-cycle battery. Deep Cycle batteries provide sustained power over a longer period of time. Compared to SLIs, this makes them more ideal for marine vehicles, small recreational vehicles and golf carts. If your battery is stock, it is likely an SLI battery.


Batteries come in specific sizes and configurations and have specific cranking amps (ca: amps for starting), cold cranking amps (cca: amps for starting at 0°F), and reserve capacity (RC: has more charge in it, usually a physically larger battery).


Basically, a lead-acid battery cell is 2 volts and 6 cells make up a 12-volt battery. But 2 volts per cell is a nominal value. A 100% fully-charged lead-acid battery will read 12.6 volts or so if there is no load on it (open).


Many people have an absorbed glass mat (AGM) battery. I do. A 100% fully-charged AGM battery will read 12.7 volts or so if there is no load on it (open).


An approximate indication can be done by measuring open circuit voltage. Disconnect the battery from the car and measure the voltage with a decent voltmeter, preferably at 80°F: 12.65V = 100% charged; 12.45V = 75% charged; 12.24V = 50% charged; 12.06V = 25% charged; 11.89V = Discharged. If you want a better indication, have it load tested. If it is discharged, try charging it with a good charger. It it takes the charge, you are good to go, If it doesn’t it’s new battery time. I recommend and use a Schumacher charger myself. Mine let's me select the battery-type I have installed.

Also, you can't charge a 12 volt battery at 12 volts. It won't charge. The charging voltage is somewhere about 13.4 - 13.8 V. If your voltage regulator fails and you get up to 15 V or more of charging voltage, you will cook the battery and cause it to fail, sometimes catastrophically. I had a Mazda MX6 GT that cooked my battery and spewed battery acid all over the under-hood area around the battery. Not fun and not easy to fix.

Best of luck to you.

 

[Elp_jc]

Also, you can't charge a 12 volt bettry at 12 volts. It won't charge.

Indeed. The car is merely supplying voltage to the electrical/electronic components; not charging the battery... but not discharging it either. Apparently that's what BMS does when battery is fully charged, to save a fraction of a MPG. But it's a good system. It also decouples the alternator (basically 0% load) during WOT if battery is charged enough. It's a good (and smart) system IMO.

 

[Emilbadal]

Hi everyone, For the couple of past weeks I noticed that my car wasn’t starting as strong as before 2 days ago I took it to a shop to see if the battery is going bad. They told me that the battery is fine, it just needs being charged. 3 days a week I commute to work and my commute is a little over an hour each way. It’s a 2016 model and is still the original battery. I was doing my Kicker key amp tuning and as it finished, the car failed to start. So I took the battery out and put it on my battery charger. Given that the battery recovers and holds charge. My question is, do I need to reset the BMS after charging the battery up?

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