2.x to 2.8 Battery Tube Upgrade


Over the past few months there have been many inquiries about how to upgrade an older version OpenROV to have the new battery tubes that are on the v2.8. The new features include:

  • Integrated polyfuse at the rear of the battery tube
  • Twist lock endcaps to easily change the batteries
  • Ranger bands to hold the tube onto the shell (getting rid of zipties and straps)

We have just released a new kit in the OpenROV Webstore: The 2.x to 2.8 Battery Tube Upgrade Kit

This kit comes with all the parts you will need to upgrade your v2.5, v2.6, or v2.7 to the latest battery tubes. We have also released the directions in order to make the upgrade.

We hope you like the upgrade and as always please let us know if you have any feedback.

OpenROV rebuild v2.7 to v2.8 is that possible?

Thanks for making the upgrade kit! We made it work with the older style protected batteries.

We’re using KeepPower 26650s which are 202mm long. The TrustFires were 209mm long so our original 2.6 battery tubes required washers to make contact with the batteries. Our fear was that the new tubes designed for the shorter LiFePo batteries at 196mm would not fit our existing collection of KeepPower batteries.

We applied the battery tube upgrade to our 2.6 OpenROV and it works! Brian helped us figure out that we could leave out the polyfuse and a piece of acrylic to make our longer batteries fit. I’m here to say that it (mostly) worked and we are almost diving again.

PS: Don’t put the ROV in the oven! Things like battery tubes and the exterior shell get soft and deform at 200 degrees… I thought I was cleverly drying it out but instead killed our working ROV. I wanted to upgrade the battery tubes anyway…


“Don’t put the ROV in the oven!” - Hillarious! We need that as a warning
sticker :smiley:
I didn’t know about the 26650 form factor. Looks very interesting. Has
anyone had experience with the ThorFire brand? They seem to be cheaper but
include all the protection circuitry as well…


Just for clarification purpose this is removing the polyfuse adapter that is used as a spacer at the front of the tube since there is one integrated into the back of the battery tube. You still need a polyfuse in line with each battery tube.


No, actually we left out the polyfuse and its spacer. The batteries we are
using have internal protection.


How did you seal the rear of the battery tube without the polyfuse?