7345 charger mod
In old post: > How does the PD9260 stack up to Parallax 7345? Salvo mentions how to modify and increase the charge voltage of the Parallax 7300. Could someone please point to the thread that conta...
Forum Discussion
Sam,
My Parallax 7345 converter (2-stage) was so slow in charging, I decided to either chuck it or modify it into a turbo mode. It was slow in charging because I had 20 mohm line drop on the positive cable. It would have been a major hassle (and expense) to replace my 8 awg cable which is over 20 ft long. I decided to modify the converter and locate the feedback voltage directly at the battery. The 20 mohm line drop is now eliminated.
This procedure only works for the 7345 converter. There's a resistor divider network consisting of R32, R33, R34. One side of R32 connects to the output voltage (this is the feedback voltage), the other side connects to R33. Lift the lead of R32 that connects to the output voltage. Solder into the vacated resistor lead hole a small signal diode (1N4148 or what ever) - anode side into the hole. Connect the diode's cathode side to resistor R32 lead that's in the air. Solder a 100 ohm resistor to the same junction (R32 & diode cathode). Connect a wire to the other side of the 100 ohm, 1/8W resistor and run it to the battery positive terminal. That's it!
The diode is for protection. Should the feedback wire (the new wire going to the battery) open, the converter will limit output voltage to a safe level.
Hurricaner- I go to Gooseberry Mesa to mountainbike every spring. Great place!
Cal
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/21456904/gotomsg/21484761.cfm#21484761
If the above seems confusing or overwhelming... I recommend a replacement converter.
My Parallax 7345 converter (2-stage) was so slow in charging, I decided to either chuck it or modify it into a turbo mode. It was slow in charging because I had 20 mohm line drop on the positive cable. It would have been a major hassle (and expense) to replace my 8 awg cable which is over 20 ft long. I decided to modify the converter and locate the feedback voltage directly at the battery. The 20 mohm line drop is now eliminated.
This procedure only works for the 7345 converter. There's a resistor divider network consisting of R32, R33, R34. One side of R32 connects to the output voltage (this is the feedback voltage), the other side connects to R33. Lift the lead of R32 that connects to the output voltage. Solder into the vacated resistor lead hole a small signal diode (1N4148 or what ever) - anode side into the hole. Connect the diode's cathode side to resistor R32 lead that's in the air. Solder a 100 ohm resistor to the same junction (R32 & diode cathode). Connect a wire to the other side of the 100 ohm, 1/8W resistor and run it to the battery positive terminal. That's it!
The diode is for protection. Should the feedback wire (the new wire going to the battery) open, the converter will limit output voltage to a safe level.
Hurricaner- I go to Gooseberry Mesa to mountainbike every spring. Great place!
Cal
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/21456904/gotomsg/21484761.cfm#21484761
If the above seems confusing or overwhelming... I recommend a replacement converter.
