2017 Honda Charging, stays at 14.4V

[Sequoiasoon]

I have 3 Honda's, various years with the Honda charging algorithm.

My 2017 Accord, 2.4L 6MT seems to be staying at 14.4V, I think. I need to watch more on my daytime drives. All my Honda's go to 14+V when headlights are on. I do recall my plug in phone charger showing varying voltage in the past. It's not exact but close. I think it used to drop even at clutch in shift. I work nights so going to work obviously lights on, full voltage.

Battery is a 2 year old Honda 51R. Last tests 2 weeks ago showed it at full CCA if not higher, I'll check again tomorrow after it sits overnight. I'm wondering if my negative load sensor is bad? How do I test that? I got home from work, put my Fluke DMM on it showed the 14.4V. I turned every electrical on I could and it held the 14.4V, quick drops to 13.0 when AC compressor and fan kicked on but right back to full.

Old school we always wanted full voltage like that. Many hate the Honda and I think would "like" this issue with stereos etc. I just want to make sure it's working correct and not trashing other stuff.

I'll keep monitoring but it doesn't get really short drives. 25-30 minutes to work and then back, mix highway and local but no real traffic.

 

[IndyIan]

My Impreza runs the same way, once the head lights are on, it just keeps the voltage up near the 14.4 range. If I turn the headlights off, then it will use efficiency strategies and run the battery down to below 12V before running the alternator to charge it up again.
I assume our Outback does too, but I've never really run it with the scanguage to look at it.

 

[SC Maintenance]

14.4V sounds like full charge all the time.

Sounds like maybe your voltage regulator is fubar?

 

[martinq]

Have you found any service information for this car? I'm curious what the alternator test procedure is.

 

[JHZR2]

14.4V sounds like full charge all the time.

Sounds like maybe your voltage regulator is fubar?

At constant voltage the current will drop as the battery gets full….

 

[SC Maintenance]

At constant voltage the current will drop as the battery gets full….

So Honda holds the high voltage and only drops the current? No vehicle I have ever owned does that, but I have never owned a Honda.

Also, 14.4V is a very high over voltage.

 

[JunkdrawerDog]

My Impreza runs the same way, once the head lights are on, it just keeps the voltage up near the 14.4 range. If I turn the headlights off, then it will use efficiency strategies and run the battery down to below 12V before running the alternator to charge it up again.
I assume our Outback does too, but I've never really run it with the scanguage to look at it.

This seems to be common these days. Since I short trip mostly, I always turn on the headlights, or HVAC blower, or both to encourage the system to fully charge the battery.

 

[CleanSump]

This seems to be common these days. Since I short trip mostly, I always turn on the headlights, or HVAC blower, or both to encourage the system to fully charge the battery.

That's an old school myth. The extra "juice" is powering the lights and fan, not helping to charge your battery at all.

 

[JunkdrawerDog]

That's an old school myth. The extra "juice" is powering the lights and fan, not helping to charge your battery at all.

Is there a way to do so? Maybe I'm doing it wrong. Or am I (we) just stuck with what the charging algorithm deals out?

 

[meep]

So Honda holds the high voltage and only drops the current? No vehicle I have ever owned does that, but I have never owned a Honda.

Also, 14.4V is a very high over voltage.

Current pull - It’s not the vehicle but rather the way the battery works. It “allows” less to flow through it as it charges.

Voltage is probably ok I’d say. 14.4 would be a solid “float” voltage for a cycled battery. If it was a standby battery that charges for weeks at a time it would be too high. It would be fairly safe to regulate there. I’ll bet however when the vehicles lights are off during daylight hours, it stays less and fluctuates a lot with driving conditions … lower V at cruise, higher during coasting and deceleration.

 

[CleanSump]

Is there a way to do so? Maybe I'm doing it wrong. Or am I (we) just stuck with what the charging algorithm deals out?

Stuck with the algorithm if the computer is controlling the alternator output.
You might want to put a charger or Battery Tender on like once a week to bring the battery up to full if you short trip a lot and the battery is never fully charged.

 

[JunkdrawerDog]

You might want to put a charger or Battery Tender on like once a week to bring the battery up to full if you short trip a lot and the battery is never fully charged.

That's exactly what I did at my old location. I had the 1.25A Battery Tender. No practical way to do that at my current location. I'd have to park in a different place and ask a neighbor to let me run an extension cord from their patio. I don't want to be that guy, lol.

 

[CleanSump]

That's exactly what I did at my old location. I had the 1.25A Battery Tender. No practical way to do that at my current location. I'd have to park in a different place and ask a neighbor to let me run an extension cord from their patio. I don't want to be that guy, lol.

I used to use a solar charger on the back shelf when I flew 3 weeks out of the year. Kept the battery up while in the Airport parking lot. I just had to park in the outside lots or top level of the parking garage.

 

[Sequoiasoon]

Current pull - It’s not the vehicle but rather the way the battery works. It “allows” less to flow through it as it charges.

Voltage is probably ok I’d say. 14.4 would be a solid “float” voltage for a cycled battery. If it was a standby battery that charges for weeks at a time it would be too high. It would be fairly safe to regulate there. I’ll bet however when the vehicles lights are off during daylight hours, it stays less and fluctuates a lot with driving conditions … lower V at cruise, higher during coasting and deceleration.

That's just it. The last bunch of days driving home daytime when I look it doesn't drop. No lights on, no defroster on, climate control / fan off just fresh air setting.

That's an old school myth. The extra "juice" is powering the lights and fan, not helping to charge your battery at all.

The extra juice at least in my wife's Pilot is 14+V vs 12.8V. It does more than just power fand and factory LED lights. A week or 2 of doing short trips with lights on has her battery at a higher resting voltage (sitting 12 hours overnight). No lights it slowly drops. Many know their cars and I'm sure you have heard car crank just a bit slower even when outside temperatures stay the same.

All the cars my wife has had did that. Her 2 mile to work just isn't conducive to charging time. I think the toughest was actually the yellow top Optima in the Sequoia. Every 6 months you could hear the slower crank. It took a while to get that to full charge. That was actually when I bought my CTEK 7002 which has a setting for spiral cell.

 

[IndyIan]

That's an old school myth. The extra "juice" is powering the lights and fan, not helping to charge your battery at all.

Well, the system voltage that the ECU sees, is the voltage of the battery unless you have bad connections?
If the engine isn't running, running the regular accessories won't put the voltage down to 12V instantly. If you start with a fully charged battery at 12.8V(or a 14.4V surface charge), it will keep above 12.0 V for quite a while, and that's why manufacturers shut the alternator off, as there is efficiency in not keeping current going to the battery to keep it at a 14.4V "surface charge"

In the summer I don't care if the car is shut off with the system voltage at 12.1V, but in the winter I'd rather have that battery topped up all the way in case I see -32C the next start.

 

[JHZR2]

So Honda holds the high voltage and only drops the current? No vehicle I have ever owned does that, but I have never owned a Honda.

Also, 14.4V is a very high over voltage.

The battery naturally drops charge current as state of charge increases. Higher delta from supply voltage vs open circuit voltage.

 

[IndyIan]

So Honda holds the high voltage and only drops the current? No vehicle I have ever owned does that, but I have never owned a Honda.

Also, 14.4V is a very high over voltage.

I guess it is, but I had my Focus alternator rebuilt and it sat all the time at 14.9 V in the cold and 14.5-14.6V in the summer. It didn't seem to bother the battery too much, it went for 8 years with the alternator running like that. I always did run the headlights so maybe they helped keep the battery from overheating, and 95%+ of my driving is hwy?

 

[CleanSump]

I guess I need to go back to Engineering School because my books and professors were all wrong.

 

[SC Maintenance]

Current pull - It’s not the vehicle but rather the way the battery works. It “allows” less to flow through it as it charges.

Voltage is probably ok I’d say. 14.4 would be a solid “float” voltage for a cycled battery. If it was a standby battery that charges for weeks at a time it would be too high. It would be fairly safe to regulate there. I’ll bet however when the vehicles lights are off during daylight hours, it stays less and fluctuates a lot with driving conditions … lower V at cruise, higher during coasting and deceleration.

I don't think that is technically correct. A battery does not really "pull" current like a load - its actually a supply by definition.

In order to push against the supply enough for it to receive a charge you need an "overvoltage" of at minimum 1V over nominal. So with a 12V, 6 cell battery being around 12.6V at full charge, a float usually technically requires an additional 1.0V absolute minimum.

Both my Toyota and Nissan's seem to float around 13.8V, they charge at around 14.2V. Constant 14.4V seems high to me but possibly OK. Its definitely not a float voltage for a lead acid battery.

 

[daniel327]

My Toyota charges at 14.4v at all times. (I have a dash mounted digital volt meter). It has done this for over 13 years. In this time it has only needed 3 batteries. So, IMO, there is no problem with op's charging voltage.