Here's a battery pack I made for my GPX. I used 18650 rechargeable batteries which is probably the most common kind used for built in battery packs like for laptops and flash lights. I used the plug off some old computer speakers that plug into a 4.2 low latency bluetooth transmitter (the white round disk). The power leads were then soldered to a Fatshark Battery Box used for powering Fatshark Drone goggles. You can use any 18650 battery holder but I liked the fatshark battery box because it has the battery indicator on the side. It's important when building an alternative battery sources to use good quality batteries and charger. The batteries are Panasonic rated at 3400 mAh. You can find batteries with higher ratings but it will be junk as 3400 is about the current max output for good 18650s. The longest I've gotten to hunt is 2 hours and I showed half charge so I feel confident I can go 3 to 3.5 before putting two more in and I have 8. The setup is extremely light and I have several bluetooth options including Sony and Minelab earphones but prefer ear buds as the sound is crisper and it's cooler in summer.
Find's Treasure Forums
Welcome to Find's Treasure Forums, Guests!
You are viewing this forums as a guest which limits you to read only status.
Only registered members may post stories, questions, classifieds, reply to other posts, contact other members using built in messaging and use many other features found on these forums.
Why not register and join us today? It's free! (We don't share your email addresses with anyone.) We keep email addresses of our users to protect them and others from bad people posting things they shouldn't.
Click here to register!
Need Support Help?
Cannot log in?, click here to have new password emailed to you
Changed email? Forgot to update your account with new email address? Need assistance with something else?, click here to go to Find's Support Form and fill out the form.
GPX Custom Battery Pack
- Thread starter soky72
- Start date
I picked up my GPX used a couple years back as I didn't want to spend a ton on it if it wasn't what I wanted. Little did I know it's the greatest thing since sliced bread. Anyway the detector was used by a prospector up north and very worn cosmetically but has worked like a dream and I got it and a load of stuff cheap enough that I haven't worried about experimenting and have no idea if it even has any warranty. Besides I'm not sure if it's any different then using an aftermarket battery source like the Screamer??? The two 3.7 volt 18650 batteries equal the 7.4 volts needed for the GPX. Some people use the 7.4 volt LiPo RC batteries which can be purchased in much higher mAh ratings but LiPo batteries are more dangerous and need more maintenance then I want to put in but it would be no problem to switch to a LiPo, just unplug the fatshark battery box.
Neat job, Soky. I still have the factory battery and may want to sell it at some time. I really like the Screamer because of the volumn adjustment being so handy. However, If I did not have it, I would be looking at your design. What type of connection cable do you use and what do you think the total cost of yours would be?
Cookie58, if you use a Bluetooth setup your amplifier will be in the headphones or earbuds and you can make it so loud it's not bearable at least to me. I did have the stock battery mounted on the side and I still plugged in my Bluetooth transmitter and used Bluetooth ear buds. Once you go wireless it will ruin you to cords. As for cost a bit hard to say but it wasn't bad. I had a bunch of power cords in different lengths I got with the detector so I cut one down but you can buy the the 5-pin power cord plugs online for about 7-8 bucks. Only 4 of the pins are used and you could buy wire about anywhere to solder to the pins then shrink wrap the wires together. From there I soldered the positive and negative power leads to a Deans Connector, popular in the RC world. The other 2 wires are the positive and negative for the audio and they went to the audio plug salvaged from old computer speakers. I then soldered a Deans Connector to the Fatshark battery box which are $15-20 bucks online. The FM transmitter was $40 but I've seen similar since for $25. My ear buds were like $40 and I have Sony Headphones, an Xmas present, Minelab M80 headphones and receiver from my Equinox 800. The 18650 batteries were $17 for 2 and the universal charger was $30. Thing is I use the Bluetooth stuff all the time while working on projects, mowing, working out, etc. The Bluetooth transmitter can be hooked to your tv for watching quietly and I use rechargeable AA's in everything so the universal charger is handy. I'd own most of these items even without my detector. Plus the setup is very light and unobtrusive.
Digger70pa
Well-known member
Wow those two little batteries power the machine for 3.5 hours? That's awesome.