Tip

Check jump-terminal voltage before diagnosing a dead 12V battery

4 months ago

A reported “dead” or weak 12V battery may sometimes be a communications issue instead. In one case, Pebble support was initially unable to communicate with the trailer but later took remote action that restored communication. A voltmeter at the Pebble jump-start terminals showed 12.4V even while support reported the 12V was dead.

Before deciding that the 12V battery is dead, check the voltage at the jump terminals. Owners have received conflicting information about battery health in these scenarios, and sometimes the problem is trailer communication rather than the 12V battery.

12v-battery diagnostics jump-start maintenance

11 comments

3mo ago

Have voltmeter, will travel with it.

3mo ago

Have any of you who have had to take the cover off to access the 12V battery figured out either (a) a way to remove the cover without breaking the plastic clips or (b) another way to secure the cover plate that is easier to remove when access is needed?

3mo ago

The simplest solution if I have to access it again might be to secure it with a short bolt and wing nut, but I am interested in whether anyone has come up with something better.

3mo ago

Take the center out first—the little round center piece. Use a small flat pry bar, the foot-long variety. A flat screwdriver won't work. Then you can get the outer piece off with the same pry bar.

3mo ago

The cover with the easy-to-break clips is the one on the bottom at the front-left side covering the jump-point terminals, not actually the battery cover. Those clips suck. I tried two official clip-removal tools; neither worked. I got frustrated and broke all four off, and will find better alternatives.

3mo ago

Another idea is drilling a second hole and using zip ties to secure it. Then just cut them off and replace with new zip ties each time you access the battery jump terminals.

3mo ago

The plastic rivets Pebble uses have a cap that is too thin for a reusable rivet. I used a removal tool specifically designed to remove the center pin of plastic rivets, and the cap of the pin still sheared off.

I replaced all four with alternatives from a local hardware store. Their center pins are thicker with more prominent heads that hold well but can be gripped and extracted easily without breaking. I also attached a Bluetooth battery monitor so I can keep an eye on the Pebble 12V without regularly pulling the access panel.