Volt meter question

So wondering if this is normal (and I just haven’t noticed). My volt meter seems to be charging at a lower level than usual. Sometimes it goes back to right about in the middle but lately it seems lower than usual. This is a hybrid truck btw


here’s where it usually sits

 

Halfway point would be around 14 volts. Little under half 12 or 13 volts looks normal to me.

 

Voltage is going to change based on current charge and demand.

 

Looks normal to me. If it is a hybrid like mine it has a power inverter instead of the conventional alternator we were used to for keeping up the batteries for the electric assisted motor in the drive line.

 

That is where mine is too. I don't understand whey we get that scale of 9-19 with no other marks. I'd love to see the actual voltage.

 

Yes, this is normal. Unlike older vehicles, where the voltage regulator kept the voltage constant at around 13.8V, modern vehicles sense the charge level of battery and vary charging profile accordingly. 13.8V was a compromise between a voltage high enough to charge the battery but not too high to overcharge and destroy it.
Immediately after starting the vehicle, the charging system will raise the voltage to about 14.4V to quickly replenish the battery charge. Depending on the charge state of the battery, this phase can last from only a few seconds to many minutes. Once the charging system senses that the battery has reached target charge state, it will lower the voltage to around 13.3V and keep it there. This charging program prolongs battery life.

 

Nissan does the same thing. The voltmeter has no graduation marks. Just points to a spot on a gauge but no markings.

 

Mine sits at 12.5 much of the time. That is the loaded voltage I take it. Using the Scanguage 3, I always have my voltage up there. When idling, when taking off and accelerating, the charge voltage drops to save fuel usage. When cruising at a stable speed the charge will go up to 15.2 volts at times to soak the battery.

 

Normal, Toyota uses a smart alternator that fluctuates its output based on engine load to help with fuel economy

 

Ugh, so it's like Nissan and VVCS... Time to figure out how to disable that bs.

 

The voltage changes are there to protect the battery and extend its lifespan. If you run the alternator voltage constant around 13.8V (like it used be in the past), you "cook" the battery once it's fully charged.
That's why modern alternators (and smart battery chargers) deliver a higher voltage (~14.2 - 14.5 V) initially to quickly top up the battery, but once they sense that battery has reached 80-90% of its capacity, the voltage drops to 13.2 - 13.3 V to maintain the charge and protect the battery from overcharging.

 

Never had a cooked battery from an old fashioned alternator in my life. Interesting. Also, people that have agm batteries need the higher voltage, so being able to disable the alternator nanny is still something some of us want to do.

 

In most modern cars you can "tell" the ECU what type of battery you have and it will configure the charging profile accordingly.

 

Do you have info on how to do this on a tundra?

 

No, but you can find all technical information here
https://techinfo.toyota.com/techInfoPortal