Tdi Pro 5 x 18650 high voltage battery build.

[karelian65]

Sorry about the delay.. Final views and opinion on the battery posted shortly. Just rechecking that the dedicated 5 x 18650 charger works as it should with the battery pack. Also want to take the machine into the goldfields to compare in ground performance. It works great on the beach. Parts list etc will be included. I'll get it done as soon as the rain stops. Tdi Pro modified with upgraded battery pack will get it's last hunt with me before it is sold..

 

[karelian65]

I've been putting the battery pack through it's paces. Left it in the machine for a month, no parasitic drain or other issues. Ran it down and recharged a few times, again it seems to work as it should with its dedicated charger.
The heat shrink material is best worked with a hair dryer, do not use lighter or flames or any kind. Hot air is enough. My second attempt sees me happy enough with the heat shrink. I'll be using the same material when I rebuild the factory battery packs using new cells in the future. After this battery build the idea of refurbishing old packs with new cells is fast gaining momentum.
I've got enough parts and cells to build another pack for the Tdi Pro modified unit. Two battery packs should be enough for one full days detecting.
More to follow shortly, just organizing a day out in the goldfields to more fully explore the machines potential with the higher powered battery. So far it works great on the beach and I expect the same when prospecting.
All the best.

 

[karelian65]

Runtime is roughly 4 hours if starting with a fully charged pack at 21.5 volts. I charge to 20 volts and get just over three hours.. ok not fantastic but it is what it is..

Started today at 19.53 volts, an hour later it was 18.47 volts. Add another hour and it was 17.74 volts, hour later 16.76 volts and twenty minutes later the pcb shut the machine off at 15.97 volts. The PCB is set to turn off at 16 volts to protect the cells from over discharge, a good thing in my book. You can see why another spare battery is a good idea.. I ran the machine with the speaker on, no headphones. Headphones will buy you extra time as will fully charging the battery pack to the maximum 21.5 volts.
More to follow. All the best.

 

[karelian65]

Focusing on the dedicated charger. It is designed for 5 x 18650 battery packs and works well so far. The only issue is that it comes with a 2.1mm male plug which has to be swapped out for the female equivalent. I did so and it worked for a while, the plug is faulty and has now failed. Swapping out for a more robust alternative from another brand. Waiting for the postman to deliver and then will make the alterations. I'll include the more robust design plug in the parts list. Using my brothers expensive smart charger until the modification to the design is complete. The dedicated charger will be tested again to make sure it is working as it should. More to follow, all the best.

 

[karelian65]

Recommend the larger plugs that have the plus and minus labelled, just easier to see and a pleasure to work with. The smaller plugs are fragile and finicky unless your eyes are young and soldering skills up to scratch..

 

[Jaros]

Just takes a bit of practice and having to use a heat sink to draw the heat away from the plastic or component.