Sunday, June 01, 2008

I'm Getting A Charge Out Of You

This is the Manzanita Micro PFC-20 Charger that I have installed in the truck of the VW. The "AMPS" control sets the charging current. I have marked two positions: 15 AMPS (for charging from a normal 120V household outlet) and a 20 AMP position, which it is currently set at. (I have a dedicated 20 AMP circuit in the barn.) If I used the 20 AMP position for "away from home" charging, I would probably trip the circuit breaker ... NOT a good way to impress friends and neighbors!

These are the controls for adjusting the time the charger "floats" the battery pack after charging. This is to balance the sixteen batteries in the pack.
The left arrow points to the rotary switch that lets you "guess" what the balance/float time is. It is a 16-position rotary switch with no hint as to timing except to state that the "three o'clock position" is zero time ... it's kind of a "try it and see" approach. (This could be improved.) This is why I'm using the recording chart device to monitor the times.
The right row of switches (installed upside-down ... intentionally, I guess for assembly convenience) selects the various charge/float options. The #1 switch ON, as I have selected, selects the option for the balance/float to start as soon as the charger senses the pack has reached the selected charge voltage.

A vintage Omega chart recorder that I bought on eBay, several years ago. This is the first real application that I have used it in. Works great!
Here is the latest recording that I made after after an eighteen mile trip to Pullman and back. You can see that the charge time was 3.5 hours, followed by an approximate one hour very low power balance/float.

With the current cost of electricity here, the total trip cost would have been approximately TWENTY CENTS! I say: "Would have been," because our solar electric system is currently generating MORE power than it takes to recharge the car. We get free "gas" and what's left over, we sell back to the power company! What's better than that?
See ->

(CLICK pictures for a larger image)