Original deus batteries(coil, remote control, headset) have 400mA capacity. This gives approximately 6 hours autonomy (it depends a little bit on frequency used and TX power).
Later, XP released a second coil with 57% more autonomy that gives for example 14 hours autonomy in GMP program.
So the coil autonomy is great with this new battery, but:
- what about the users that have the old coil? They need to send it to XP for battery replacement in order to benefit from the new capacity.
- what happens when you are outside in the field and your detector just stopped working due to battery void: you should normally stop during half an hour, charge your battery at the car and then detect again for some time and repeat the procedure.
- what happens if you forgot to charge the deus during night and you just want to go outside, should you now wait some hours?
- what happens in some years when your battery will fail: you should send the detector to XP and wait for some days during wich you cannot detect.
Originally I had a kind of "bug" due to my protection of the coil: I need to remove this protection each time for charging the coil...this was a disadvantage. So finally I decided to transform this bug into "a feature", here is the result:
The wires are fixed on the charging pins through some thermofuse glue (of course this can be removed without any warranty loss):
The 2 wires go through the plastic tube and are maintained stable (otherwise you got false sound signals) through a piece of cork.
At the end of the 2 wires, there is a home made connector that is also used for charging the coil without using the standard connector: therefore I do not need to remove the black protection bag that I have put over the coil.
In case the battery of the coil is void, I have a second battery of 900mA fixed under the armsupport: this gives in addition some weight that better equilibrates the detector from my point of view but this is dependant of how you carry and move the detector.
The additional weight of 70gr + 20 gr for the wirings is acceptable. This second battery then charges the Lithium battery of the coil and you can continue detecting DURING the charging process.
An additional piece of cork at the top of the stem maintains the wires inside the stem so that they do not move.
Here a last picture in order to see the complete wirings:
Complete costs of this modification are: 4€ for one battery pack of 4 AAA (LR03), some wires and connectors.
Of course you could imagine have a second battery pack that is charged through solar energy (or at your car) during the time you detect and then you have a (quasi) infinit autonomy.
In case of questions, do not hesitate to conctat me.