Use a Inline fuse!

[CloudChaser]

I built my mod with the following parts:
Hammond ABS 1591 C project box
VariTube 510 connector
Mitec 16 mm fire button
2 C&K tactile switches (Watts Up/Doun)
Turnigy nano-tech 2250mah 3S 65~130C Lipo Pack
DNA 200

Everything worked great for 2 weeks. One evening when I was taking a deep throat hit I heard a quick buzz (less than 2 seconds) and the board was dead. I removed the back cover and that familiar smell hit me. Burnt semiconductor. After inspecting the mod I found to things:

1) The on board fuse opened.
2) The solder connection to the 510 pin had melted. The buzz I heard was probably coming from arcing on the 510 connector.

I replaced the on board fuse and also added an inline 25 amp fast acting fuse and modified the 510 connector with a heavy spring but it was too late. The board powered up just fine and I plugged into my pc and started the Device monitor. Right away I noticed the board was running 20 – 25 degrees hotter than before. I took a couple 50 watt throat hits and the unit displayed “Warranty Service” message. Also it takes 18 hours to charge the battery and it used to take roughly 6 hours. Charging would shut down when the board reached 130 degrees. The board is toast.

My new board will be arriving Monday and my question is, is a 25 amp fast acting fuse too high? Any input would be appreciated

[blueridgedog]

Specs are that it can draw 23 amps.  If the 510 joint melted, perhaps it was a cold joint.  As to the "Warranty Service", that is a badly out of balance battery pack.  Did you note the cell charge levels before shipping it off?  It sounds like one of the cells sagged badly during the shorting event.

[CloudChaser]

Hi Blue. Definitely there was something wrong with the solder joint although it looked fine after soldering. I did not ship the board back as I did not think it was covered due to the nature of the failure.

I had the same thought about the battery but all the cells were within 0.01 volts of each other and all cell values added up the pack voltage. The fact the board temperature was 25 degrees higher told me one or more of the semiconductor components are shorted. Electronic devices go through 3 stages. Normal, shorted and open. I believe one or more of the components are in the shorted stage. The board would not charge the battery due to the temperature spike when the USB cable was plugged in. I removed the battery and used my external charger and used the mod until yesterday when the new board arrived.

I was able to use the board however I could not set wattage above 40 watts. If I went above 40 watts the board would shut down and reboot. I received the new board yesterday and modified the 510 pin. I drilled out the wire hole to accept the 14 awg wire. I also put a 1.5 lb spring in and you can definitely feel the difference when you screw the tank in. The new spring also got rid of the resistance variation coming from my Kanger sub tank. Currently all is well.

Does Evolv repair boards?

[blueridgedog]

CloudChaser said:

Does Evolv repair boards?

I have sent them 7 boards and always got new boards in return.