DC Voltage Readings

[arcticfox2005]

Re a motorhome on a Ford E450 chassis.

Assume fully charged house batteries. When plugged into shore power, will the converter immediately jump the battery voltage from about 12.6 up to about 13.5, in spite of the fact that current flow will be very low?

What about when the engine is started? Will the alternator produce the same effect?

 

[JayArr]

Within a few seconds I would think.

 

[donn]

If your converter is working, yes it should.

 

[DonTom]

Re a motorhome on a Ford E450 chassis.

Assume fully charged house batteries. When plugged into shore power, will the converter immediately jump the battery voltage from about 12.6 up to about 13.5, in spite of the fact that current flow will be very low?

What about when the engine is started? Will the alternator produce the same effect?

I would expect the regulated rectified charging voltage from alternator to the battery to be higher than your converter right after you first start the engine (above 14VDC). Then drop down after a minute or two (usually close to 13.8 VDC).

-Don- Reno, NV

 

[John From Detroit]

The alternator may go to 13.6 or even 14.6. On starting it's in "BULK" mode to swiftly recharge the starting battery.

On the other hand. depending on how big and long the connecting wires are (smaller and longer = slower charging) it may take 'em a bit to read the alternator's output.

GM's tend to run a bit "hot" on the alternator.. Kept tripping the overvoltage alert on my power strip. And that was on the HOUSE Batteries... That said. I do not know the high voltage trip point. (OK check the maker's spec sheet. 15 volts high 11.x low) It's a West Mountain Rig Runner 40/12
(40 amps total current, 12 pair of Anderson Power Poles... Though I no longer have the motor home. I still use the Rig Runner.. Running 2 ham rigs. a weather radio and a fan that I'm sure of.)

 

[Lou Schneider]

Re a motorhome on a Ford E450 chassis.

Assume fully charged house batteries. When plugged into shore power, will the converter immediately jump the battery voltage from about 12.6 up to about 13.5, in spite of the fact that current flow will be very low?

What about when the engine is started? Will the alternator produce the same effect?

Voltage is pressure, current is quantity. Multiply the two together and you get power (watts).

The alternator or converter increases the voltage at the battery terminals compared to the battery itself. This pressure then forces current into the battery depending on the battery's state of charge. Anywhere from several tens of amps if the battery is low to nothing if it is fully charged.

 

[Kirk]

to nothing if it is fully charged.

The charge current will drop to 0A when battery voltage is equal to the voltage applied.