Elcon Charger - Final Charge Voltage Trim Modification
Channel: Andrew Doran
Date: 2015-05-28

ATTENTION!

DO THIS MODIFICATION AT YOUR OWN RISK, DON'T BURN ANYTHING DOWN!     Press 'Show More" \/  \/

I found this to be an easy modification, but electricity is dangerous, please work within your ability and understanding, or get help from a pro.

In this video, I show how I added some resistors to a circuit in an electric vehicle charger to adjust the end charge voltage.

I didn't invent this modification, or figure out the circuit, this is just my execution of the mod on a charger I trimmed for a friend.
Credit for this mod should be directed to this set of instructions by 'Ripperton' on DIY electric car
http://www.diyelectriccar.com/forums/showthread.php/elcon-charger-voltage-adjust-51100.html

I made a spreadsheet to calculate the resistance you need to add to trim the charge voltage to the desired finish charge. 

https://docs.google.com/spreadsheets/d/1Otz61A95O14Gu6MritbThxw0jHZXKba1YK_OCR1MM0s/edit?usp=sharing

Be aware that the 'built-in resistance values' may vary if you have a charger that is not a 1500w Elcon you can measure the existing resistance between pin 2 and ground in the circuit to confirm.  See Ripperton's PDF from the top link (you might have to sign up to DIY ElelctriCar to download the file).

The calculator provides fairly accurate values for the resistance to be added, but since everything was measured in the circuit to begin with it is not exact, so test your charger and keep an eye on the battery voltage so it doesn't get too high and blow up your pack!

It's safer to add more resistance for your first test, and then lower the circuit's resistance to increase the final charge voltage.  You have to measure the charge voltage at the end of the charge (Constant Voltage phase indicated by the flashing red LED) with the battery connected to get an accurate voltage measurement.

DO THIS MODIFICATION AT YOUR OWN RISK, DON'T BURN ANYTHING DOWN!
Good Luck.