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sparkfunX / Artemis_Global_Tracker

A global satellite tracker utilising the SparkFun Artemis module, Iridium 9603N satellite transceiver and u-blox ZOE-M8Q GNSS
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charging the GPS backup battery (and keeping it charged) #21

Closed jerabaul29 closed 3 years ago

jerabaul29 commented 3 years ago

@PaulZC I notice that I quite seldom get a "1s hotfix" on the GPS despite the presence of the battery.

I had a look at the schematics. It looks like the only way to charge the battery is to use V_USB, as the diodes would prevent other sources of power to charge it. Is this the right understanding or am I missing something? What is the recommended way to get this small battery fully charged before deployment (and to keep it charged during deployment :) )?

jerabaul29 commented 3 years ago

(would putting a jumper between the 3.3V rail and the + side of the battery help? :) ^^ ).

PaulZC commented 3 years ago

Hi JR, Correct, the back-up battery only charges when USB is connected as shown in this section. If you try different ways of charging the battery, make sure you limit the current appropriately. Connecting directly to 3.3V will release the magic white smoke... Paul