Maintaining a new battery

[The_Jeff]

Use the AC charger once a month, if that.

Your temp compensated alternator will overcharge (relatively speaking) for the first minute or two anyway because it's cold. If your battery is below 85% charge or so it will happily soak that up.

You want the periodic AC charger topoff to desulfate, as would many other people.

 

[wrcsixeight]

One can discharge a healthy battery to 50% shine a light into the cells, and see sulfation on the plates, charge it to 95%+ and wow it is gone. A miracle!!!

not.

Few vehicles overcharge, the exception is usually long drives through the desert with underhood located batteries. Usually their Voltage drops to timid levels way too soon. Your auto manufacture cares not if the battery gets back to a battery 100% state of charge.

At 77F a battery can handle 14.8v quite easily for quite a while before overcharging begins.

This forum loves to talk about the CAFE and thin oil conspiracy, but reducing loading the alternator by dropping target voltages can accrue the same micro MPG increases as thinner oils. Think they do not employ this tactic?
Each 25 amps the alternator has to make requires 1HP from the engine. more modern vehicles will let the battery provide the current rather then the alternator, and only bump up voltage, increasing alternator load when braking of taking the foot off the gas. Good for MPG, bad for battery.

https://alternatorparts.com/how-much-horse-power-does-an-alternator-make.html

Is an unregulated small solar panel hooked to a live ciggy receptacle a danger of overcharging?
It will take some time, but yes.



Those parking their cars for extended periods would be wise to figure out the parasitic draw, and do some math as to how long it takes for the battery to get drained from a theoretical 100% to 80%, and then realize they did not start at 100%.

Below 80% charged the sulfates on the plates begin hardening, becoming much more difficult to redissolve into electolyte when rechrged.

Cue to 3:50



Do note the draw can change with a certain amount of time which has passed Very variable depending on the vehicle.

Anal retentive bitogers wanting to ensure maximum batttery longevity and perhaps increase MPG by a micro fraction, should figure out a way to ensure their battery is fully charged regularly and not believe the alternator is some instant magical physics defying charging source.

but it seems many would prefer to attempt to blame the battery and try and warranty it when it is murdered by chronic undercharging.

To each their own.

Also, A healthy flooded battery kept at 75F, can self discharge 15% each month. 0.5% per day. More self diacharge at higher temps and less self discharge at lower temps.

An unhealthy battery can self discharge at a faster rate.

Combine this with the higher parasitic draw as on newer vehicles and the battery is doomed to a premature death.

 

[SubLGT]

Originally Posted By: wrcsixeight
….This forum loves to talk about the CAFE and thin oil conspiracy, but reducing loading the alternator by dropping target voltages can accrue the same micro MPG increases as thinner oils. Think they do not employ this tactic?……...Good for MPG, bad for battery….


Here is what GM's battery management (called RVC) looks like:

The purpose of the RVC system is to maintain the battery state-of-charge at 80% or above and support vehicle loads. To accomplish this, it has several different modes of operation. Six common modes of operation are Charge Mode, Fuel Economy Mode, Voltage Reduction Mode, Start Up Mode, Windshield De-Ice Mode and Battery Sulfation Mode.

The PCM/ECM (generator battery control module on full-size trucks) controls the generator through the generator L terminal control circuit. It monitors the generator performance though the generator field duty cycle signal circuit. The signal is a 5V PWM (pulse width modulated) signal of 128Hz with a duty cycle of 0% to 100%. Normal duty cycle is between 5% and 95%. The ranges between 0% to 5% and 95% to 100% are for diagnostic purposes.

The control module enters Charge Mode whenever one of the following conditions is met:

Under WOT conditions and when the fuel rate (sent by the ECM/PCM) is greater than 21 g/S and the throttle position is greater than 90%.
The headlamps are on, low or high beam.
The wipers are on for more than 8 seconds.
The electric cooling fans are on high speed.
The rear defogger is on.
The battery SOC is less than 80%.
When one of these conditions is met, the control module ramps up the voltage slowly to a level between 13.4 to 15.5V (depending upon the mode of operation the system is presently in) at a rate of 8mV to 50mV per second.

The control module enters Fuel Economy Mode when the following conditions are met:

The calculated ambient air temperature is above 32°F.
The calculated battery current is less than 15A and greater than –8A.
The battery SOC is greater than 80%.
The generator field duty cycle is less than 99%.
This mode’s targeted generator output voltage is 13.0V. The control module will exit this mode once the criteria are met for Charge Mode.

The control module will enter Voltage Reduction Mode when the following conditions are met:

The calculated ambient air temperature is above 32°F.
The calculated battery current is less than 2A and greater than –7A.
The generator field duty cycle is less than 99%.
This mode’s targeted generator output voltage is 12.9V. The control module will exit this mode once the criteria are met for Charge Mode.

After the engine has started, the control module sets a targeted generator output voltage of 14.5V for 30 seconds (Start Up Mode).

The control module enters Battery Sulfation Mode when the battery voltage is less than 13.2V for 45 minutes. Once in this mode, the generator battery control module will set a targeted output voltage between 13.9 and 15.5V for five minutes. The control module will then determine which mode to enter depending on voltage requirements.

In RVC Mode, the control module bases the charging voltage on battery SOC, which is estimated during a key-off event every eight hours, after three voltage measurements every 24 hours thereafter, and then monitored constantly while the ignition is on. These voltage measurements are then compared to estimated battery temperature, as battery temperature vs. battery voltage directly corresponds to battery SOC. While the engine is running, the system uses both the battery voltage and estimated battery temperature to determine the battery current in and out of the battery. The control module then regulates the charging voltage to keep the battery above an 80% SOC.

Reference: https://www.motor.com/magazine-summary/trouble-shooter-september2015/

 

[Mikey V.]

Thanks for the inputs. Wanted to keep the sulfation to a minimum.

 

[Trav]

Originally Posted By: Vikas
Most cars don't have "live" cigarette plug when the key is off.


Many cars have multiple outlets one of which is kept live on many cars, if not its a quick and easy job to either convert one or add one, no big deal.

 

[mjoekingz28]

Yes Trav! What a nice option for an automaker to put on a vehicle. One that is always hot and the second one only hot when keyed/ignition on.

Just something simple that can be a luxury worth alot, but costing only a little.

 

[Quattro Pete]

Originally Posted By: wrcsixeight
Cue to 3:50




When you disconnect only the negative battery cable but keep the positive connected, will this keep all your car settings or will you lose them?

 

[Mikey V.]

I've lost my car setting while disconnecting the negative battery while on deployments.

 

[kschachn]

Originally Posted By: Quattro Pete
When you disconnect only the negative battery cable but keep the positive connected, will this keep all your car settings or will you lose them?


If you plug in only one prong of your lamp cord, will it still light?

Also why these guys aren't well-done:

 

[Quattro Pete]

Thanks. Sorry, brain not firing on all cylinders this morning.

 

[mjoekingz28]

Nice perch photograph!

 

[mjoekingz28]

Originally Posted By: Quattro Pete
Thanks. Sorry, brain not firing on all cylinders this morning.

That is because your 'lobes' arent opening the valves.

 

[Quattro Pete]

Originally Posted By: wrcsixeight
Do note the draw can change with a certain amount of time which has passed Very variable depending on the vehicle.

Right, so with that in mind, how do you safely measure it when your multi-meter's 10A lead socket says "max 10 seconds, each 15 minutes?" Another words, they don't want you measuring it for longer than 10 seconds at a time.

I know my car will draw several amps initially when the battery is first connected while the courtesy lights and whatever else is on, and it'll take some 10 minutes before they go out.

Thanks!

 

[wrcsixeight]

Well, not sure about that. Use a 3$ cen teck multimeter? The fuse is easy to replace. Mine actually seems accurate down to at least 0.06 amps.

Could use a clamp on ammeter, but these generally are not very accurate under 0.2 amps, not so useful for a parasitic draw test.

Perhaps one can hook up ammeter inline, in parallel with battery terminal and battery post with post clamp on battery, wait 10 minutes for the higher loads to dissipate then pull the clamp off the battery post causing the post 10 minute current to go through the multimeter.

the 15 second max recommendation is likely at 10 amps. a 10 amp parasitic load for 15 minutes after key removal would have a very unhappy, short lifespan battery.

 

[Quattro Pete]

Originally Posted By: wrcsixeight
the 15 second max recommendation is likely at 10 amps.

Right you are. I looked in the owner's manual, and it states that if the current is 5A or less, then continuous measurement is allowed without a time limit.

 

[kb27]

Have a customer who drives very short trip daily. After 2 months, the battery was barely turning over the engine.
I checked and found it sulfated, the electrolyte was in poor condition.
I fixed it by equalizing charge.

 

[JHZR2]

OP your idea to charge it fully is perfect. Id hardwire an sae plug to your battery direct, most good chargers come with these. Just let it dangle out a half an inch and its easy to hook up!

 

[JHZR2]

Originally Posted By: Quattro Pete
Originally Posted By: wrcsixeight
Do note the draw can change with a certain amount of time which has passed Very variable depending on the vehicle.

Right, so with that in mind, how do you safely measure it when your multi-meter's 10A lead socket says "max 10 seconds, each 15 minutes?" Another words, they don't want you measuring it for longer than 10 seconds at a time.

I know my car will draw several amps initially when the battery is first connected while the courtesy lights and whatever else is on, and it'll take some 10 minutes before they go out.

Thanks!


Its the time rating of the fuse in there.

 

[Mikey V.]

While charging I noticed the battery voltage was 15.5-15.6 volts. Is this high? I'm using a Diehard Fully automated 10 amp charger that goes into maintenance mode once it's full, however once it's full I disconnect it.

 

[Quattro Pete]

Originally Posted By: JHZR2
Originally Posted By: Quattro Pete
Originally Posted By: wrcsixeight
Do note the draw can change with a certain amount of time which has passed Very variable depending on the vehicle.

Right, so with that in mind, how do you safely measure it when your multi-meter's 10A lead socket says "max 10 seconds, each 15 minutes?" Another words, they don't want you measuring it for longer than 10 seconds at a time.

I know my car will draw several amps initially when the battery is first connected while the courtesy lights and whatever else is on, and it'll take some 10 minutes before they go out.

Thanks!


Its the time rating of the fuse in there.

I get that. But if it's 10 seconds at 10A, does it mean it's more than 10 seconds at 9A? Is there a formula to calculate that, so that I don't blow the fuse?

I just want to find a way to measure parasitic drain without having to spend hundreds of dollars on a Fluke m/m.