smokeyram

Now that the temp here has really fallen off. for whatever reason, when driving my volt meter is above normal. i would say its almost 3/4 the way over to the right. new batteries, less than 2 months old. any hard that can come from an alternator Over working?

vzdude

Kind of common in the winter. May stop by a parts store to have the batteries load tested and the alternator checked for the heck of it. Battery voltage when running should be above 14 volts. I would say less that 14.8 though. Mine is usually 14.2 - 14.4.

haloman

Pretty normal. just recharging the batteries from the use of the Grid heaters.

Deezel Nate

There is a batt temp sender under one of the batteries. I think the pass side, but I don't remember for sure. It takes the temps of the battery and will have the alternator "overcharge" the batts to help warm them up.

This is why you are seeing the voltage gauge read higher than normal when it's cold.

steerjock

i know with my optimas they have a plastic spacer underneath them to bring them up to the height of the oem battery and it throws the temp sensor off.

vzdude

The temp sensor is there so the batteries aren't overcharged. Hard to charge a frozen battery! Run the risk of boiling it over or worse......it exploding!

Rare1

That is too high if it persists beyond when the engine gets up to op temp. You need to verify the charging voltage (don't trust the gauge) by putting a voltmeter on the battery while the gauge reads high, and then after the engine gets to op temp. Do this and report back.

Now, to answer your question: Of course you can harm an alternator by overworking it, but you probably are not overworking it. Your alternator is rated 146 amps? (check your owner's manual) You probably are not making even half of that.

strokerace

Mine reads about the same as yours, from what I've heard its normal because of the grid heaters

Deezel Nate

That too, but what I said applies as well.

I'm not posting just because I like to type. What I wrote is what it is guys.

Rare1

Not necessarily. My batteries are several years old, and they do not require, or get, any "overcharge" to warm up even when the outside temp is zero F. Smokyram's batteries are only 2 months old and should perform better than mine. My dash gauge goes to about 14v and stays there after the grids are finished. His should too. The question is, What is the actual voltage he is getting?

Deezel Nate

By "overcharge" I am talking like 14.5-15 volts max. Normally ~13.5v is what it will charge at. Sorry I didn't clarify.

Put a multimeter on it to see smokeyram

Tate

In the cold, mine usually charges around 13.9-14.3. Even when they are charging at 13.7, the gauge in the dash looks like it would be close to 15v.

Busboy

I have always understood that 14.7v is the max charge you should see, and any more is too much for a 12v system.

smokeyram

just as mentioned, I will have to put a meter on it this weekend. naturally its supposed to warm up, so i wont have the same climate to check in. basing off the guage, which im sure is off, looks to be 14.5-15 . again, im sure thats not accurate. when i asked, just happened to notice it was higher than i remeber seeing.

vzdude

This is the official word on the batt. temp sensor, but I'll tell ya......don't try to fast charge a frozen battery! If you watch the guage, even after the grid heaters turn off, the guage will slowly rise and the you can almost see it turning off and on. At least mine does anyhow.

OPERATION
The BTS is used to determine the battery temperature and control battery charging rate. This temperature data, along with data from monitored line voltage, is used by the PCM (ECM Diesel) to vary the battery charging rate. System voltage will be higher at colder temperatures and is gradually reduced at warmer temperatures.

The PCM sends 5 volts to the sensor and is grounded through the sensor return line. As temperature increases, resistance in the sensor decreases and the detection voltage at the PCM increases.

The BTS is also used for OBD II diagnostics. Certain faults and OBD II monitors are either enabled or disabled, depending upon BTS input (for example, disable purge and enable Leak Detection Pump (LDP) and O2 sensor heater tests). Most OBD II monitors are disabled below 20°F