Battery Voltage Question - 11.5 Volts When Off

[Starship Enterprise]

It's not the parasitic voltage that is my main point, we all know the electronics drain the car when parked. It's the toll on the battery in a few years.

I am willing to bet that no matter what new battery you put in your car and drive it daily, you will have the same issues you had the first time after a few years not using a tender on it.

I'm not going to debate this anymore.

You all do what you want, I know what works for me...

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[Paul's stable]

It's a band-aid fix to a car that has more electronic drain than the battery can handle when not being driven.

I guarantee you I'll get MUCH longer life out of this OEM battery by regularly using a tender.

My 24 DH has the factory battery have had the car 2 years on the 12 of Jan . Use a tender and have never had any problems. I also have a camera that stays on for 30 minutes until the car goes asleep.

 

[AZ_Ryan]

It's not the parasitic voltage that is my main point, we all know the electronics drain the car when parked. It's the toll on the battery in a few years.

I am willing to bet that no matter what new battery you put in your car and drive it daily, you will have the same issues you had the first time after a few years not using a tender on it.

I'm not going to debate this anymore.

You all do what you want, I know what works for me...

You realize these cars are only 1-2 years old right? Mine was toast after a year and a half as confirmed by Ford. And I used a tender! Other people are having issues after just a few months. These aren't normal cases of 3-5 year old batteries that are just wearing out.

You also dont daily your car. So not sure why your arguing with people who do over a tender.

 

[Westphal]

Maybe...But I think that point might be debatable. The alternator never brings a battery to it's peak like a Tender does.

But TBH, This debate could only be verified one way or another by a side by side controlled experiment comparison over a period of 3-5 years....who's doing that? lol

But you drive your car daily and still needed a new battery sooner than expected didn't you?

I volunteer my wife's car for the experiment. She drives it daily, except for the week we were on a cruise last week.

 

[Zig]

It's a band-aid fix to a car that has more electronic drain than the battery can handle when not being driven.

I guarantee you I'll get MUCH longer life out of this OEM battery by regularly using a tender.

Isn’t the bms supposed to manage the battery so it doesn’t need an external tender?

 

[Skye]

I've never measured current draw when starting my car. But our booster cables and the batteries are rated in the hundreds of amps.

Before the car is started, parasitic* drains will consume some energy. I follow a Tacoma forum; they often complain of the same issue: off-operation losses being a drag on the battery.

After starting the car, the charging system will run the electronics, while charging the battery. But if the demands are high enough, the battery will sometimes be discharged to support those loads. For example, don't drive often, drive short trips, winter, heated seats, steering wheel and defrost. Or in the Summer, with A/C immediately turned on.

7G cars have an Absorbent Glass Mat (AGM) batt. While the design of the unit produces more power than traditional Flooded Lead Acid (FLA) types, they also require specific charging profiles. AGMs shouldn't be charged too hard, too quickly, at the risk of gassing off some of the electrolyte solution.

If anyone is taking short drives on a consistent basis, two things can happen: 1) the battery itself could take a series of small steps down, never coming back up to full charge. 2) Sulfates**, common in FLAs or AGMs, can build up and later not be dissolved, producing a loss of capacity.

Large amounts of sulfates degrade the battery; it cannot produce as much power as before. Large, physical sulfates can break-up and settle in the bottom of the battery case; they sit there, while potentially shorting out any plates they are in contact with.

For those that drive infrequently, or often have short drives, a tender can serve two purposes: 1) keeping the battery at peak charge, 2) as part of its routine, desulfating the battery. The desulfate routine often involves a series of electrical pulses at specific frequencies. It's a form of sonic or ultrasonic cleaning.

YMMV.

* Potential Parasitic Losses
- BCM battery State of Charge measurements
- PCM emissions evaporation canister checks
- Door proximity sensors and contacts
- Trunk proximity sensors and contacts
- Hood ajar sensor
- Door ajar sensors
- Trunk ajar sensor
- Telematics modem and vehicle cellular system
- Bluetooth (802.15) interfaces (if enabled)
- Wireless (802.11) interfaces (if enabled)
- BCM background functions
- PCM background functions
- Interior motion detectors
- Vehicle movement detection
- Vehicle slope change detection
- Remote Transceiver Module (Intelligent Access)
- Engine Immobilizer (Passive Anti-Theft System (PATS))
- Driver-installed ancillary devices

** A sulfate is a salt and a derivative of the acid solution. It's normal for a battery to produce sulfates during the discharge process, and for those sulfates to dissolve, the materials returning to the electrolyte solution during the charge process.

Edit,

I'm can't define what constitutes a "short" or "long" drive. For any vehicle, I will take highway/freeway routes if possible, to bring sustained heat into all the systems and to allow the charging system to stretch it's legs. In-town, I will sometimes take a longer route, to ensure I'm running at normal operating temps for a period I'm happy with, while maximizing charging.

For all vehicles, I replace the battery every five years, regardless of condition or tells. I like replacing the battery on my schedule, versus an unscheduled event.

If you're not carrying battery cables, get a set. I've used these and like them. Not shown in the advert, mine have an in-line voltmeter, to monitor battery and charging levels when using.

https://www.autozone.com/p/duralast-gold-battery-booster-cable-bc2/125337

 

[Zig]

I've never measured current draw when starting my car. But my battery cables can carry a load up to 250A.

Before the car is started, parasitic* drains will consume some energy. I follow a Tacoma forum; they often complain of the same issue: off-operation losses being a drag on the battery.

After starting the car, the charging system will run the electronics, while charging the battery. But if the demands are high enough, the battery will be discharged to support those loads. For example, don't drive often, drive short trips, winter, heated seats, steering wheel and defrost. Or in the Summer, with A/C immediately turned on.

7G cars have an Absorbent Glass Mat (AGM) batt. While the design of the unit produces more power than traditional Flooded Lead Acid (FLA) types, they also require specific charging profiles. For example, AGMs shouldn't be charged to hard, to quickly, at the risk of gassing off some of the electrolyte solution.

If anyone is taking short drives on a consistent basis, two things can happen: 1) the battery itself could take a series of small steps down, never coming back up to full charge. 2) Sulfates**, common in FLAs or AGMs can build up and later not be dissolved, producing a loss of capacity.

Large amounts of sulfates degrade the battery; it cannot produce as much power as before. Large, physical sulfates can break-up and settle in the bottom of the battery case; they sit there, while potentially shorting out any plates they are in contact with.

For those that drive infrequently, or often have short drives, a tender can serve two purposes: 1) keeping the battery at peak charge, 2) as part of its routine, desulfating the battery, to keep it at it's highest capacity. The desulfate routine often involves a series of electrical pulses at specific frequencies. It's a form of sonic or ultrasonic cleaning.

YMMV.

* Potential Parasitic Losses
- BCM battery State of Charge measurements
- PCM emissions evaporation canister checks
- Door proximity sensors and contacts
- Trunk proximity sensors and contacts
- Hood ajar sensor
- Door ajar sensors
- Trunk ajar sensor
- Telematics modem and vehicle cellular system
- Bluetooth (802.15) interfaces (if enabled)
- Wireless (802.11) interfaces (if enabled)
- BCM background functions
- PCM background functions
- Interior motion detectors
- Vehicle movement detection
- Vehicle slope change detection
- Remote Transceiver Module (Intelligent Access)
- Engine Immobilizer (Passive Anti-Theft System (PATS))
- Driver-installed ancillary devices

** A sulfate is a salt and a derivative of the acid solution. It's normal for a battery to produce sulfates during the discharge process, and for those sulfates to dissolve, the materials returning to the electrolyte solution during the charge process.

Edit,

I'm unable to define what constitutes a "short" or "long" drive. For any vehicle, I will take highway/freeway routes, to bring sustained heat into all the systems and to allow the charging system to stretch it's legs. In-town, I will sometimes take a longer route, to ensure I'm running at normal operating temps for a period I'm happy with, while maximizing charging.

For all vehicles, I replace the battery every five years, regardless of condition or tells. I like replacing the battery on my schedule, versus an unscheduled replacement.

Since the vehicle isn’t ‘on’ during tender sessions how does the bms maintain proper status?

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