GPS battery problems (Four batteries GPS12 and III+, V)

Notice the black deposits on the battery terminals. This is carbon buildup caused by engine vibration.

Inside the battery case, the batteries are suspended between two springs. At certain frequencies (RPMs) the batteries jump around and lift off the terminals, creating a small spark each time they disconnect. After thausands of sparkings, a black carbon residue builds up between the contact and the battery terminal. Even though the batteries are not dead, the electricity can't get out thus the GPS thinks they're dead and shuts down. You can scrape the residue off the battery, but it seems to return even faster, and it's difficult to clean the contacts. For this reason we advise using external power right from the start if possible. At the very least tape the batteries and put dielectric grease on the terminals to shut out the oxygen which prevents a burning spark.

The other problem is the physical strength of the batteries themselves. Batteries are just a little rolled up can of packed powder. If you disturb the terminals in any way, they quit working. I've seen GPS batteries with terminals DENTED from violent bouncing inside the case. It seems to be worse on GPSs aligned with the plane of engine vibration (4 AAs mounted vertically as on GPS12).

"Duracell" batteries appear to have tougher terminals and last longer under vibration than "Energizers" or other brands.

Tape and dielectric grease is is the best fix we've found (to use AA batteries). It's not 100% but it helps a lot. For 100% you need to plug into 12V.

There are six connections in the battery case. Three are spring-loaded, and three are solid. Taping the batteries as shown reduces the number of 'connections' (where sparking can occur) from six down to four (three spring-loaded and only one solid). This is much better, but not a 100% fix.

Using one layer of "electrical tape" attach each pair of batteries together as shown. Use only one strip, and no wrinkles. If it's difficult to press the batteries in (with the extra thickness of the tape) it will be difficult to shake them out.

If you have to change batteries on the trail, you can carefully reuse the tape. It should be 'tensioned' such that when you lay the batteries on the table, they are at an angle as in the picture above.

The angle does two things:
1) Causes the batteries to press together in the center
2) Provides some friction on the sides, reducing the amount that they can jump around.

If you are having shutdown problems that also means too much vibration is getting to your GPS, and that means possible damage to the electronic parts. Investigate your mounting to eliminate direct contact between the GPS case and the motorcycle. And see the Vmod page.

Note new batteries inserted, but the contacts are already contaminated with carbon buildup. The terminals need to be cleaned and polished. Polishing the contacts means sanding the plating off, ....not good.....

This GPS is being used on a dirt bike. To prevent shutdown this customer needs to provide external DC to the GPS. Dielectric grease is now required on this GPS to run on batteries on a dirt bike.

<---------------In the photo to the left.

Notice the black oxide buildup on the spring contact and on the hard battery post. Under vibration, the battery disconnects from the terminal and 'sparks' thousands of times. The spark burns the metal and causes oxide buildup on the terminal. This causes shutdown, also causes your batteries to appear dead after 2 or 3 hours. You have to clean these terminals. Use very fine sandpaper, 600 or 800 grit. Scratches allow more oxygen into the spark and more burning. You want to polish the terminals as smooth and shiny as possible. It's not easy to clean the spring contacts down at the bottom of the well. Glue 800 grit sandpaper to the end of a pencil eraser and turn it in the direction of the wind of the spring.

From now on use "dielectric grease" (click here to order a 1 oz tube) to keep the oxygen out of the "spark". Radio Shack has dielectric grease and you can get it from automotive stores. You can use Dielectric grease on your turn-signal bulbs as well (especially on dualsport bikes) and all other electrical connections as it protects from corrosion and vibration.

Many dirt bikes have a "AC" generator for a small headlight. If you have a headlight, but no battery, you have AC output. You must first convert to DC output to power a GPS. We have a converter that outputs 15vDC from both 4 to 40vDC and 6 to 25vAC. See Touratech Power Converter 030-0021 (about $60). The benefit of this device over a basic rectifier is 030-0021 outputs 15vDC even when headlight is dimmed when engine is at idle RPMs. And some dirtbikes have only 6v output.