Firefox OS/Performance/Power/BatteryHarnessCosts

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Battery Harness Costing

Cost Analysis

Option 1

Part Cost
Harness $100
Ammeter $90
PCB $10
Assembly Labor 1 hour
Total $200 plus 1 hour

We outsource the harness to be printed by 3DPhactory in Toronto - they charge $96 plus shipping.

The ammeter is ordered from (, and costs about $90 including shipping.

Note that in order to be useful for the automation team, the Yoctopuce ammeter is not sufficient - we require a custom board to provide battery power switching capability.

Option 2

Our Printer, Custom Board
Part Cost
Harness $20
Ammeter/PCB $30
Assembly Labor 1-2 hours
Total $50 plus 1-2 hours

Our Printer

Buy: $10,000 (approximately)

Lease: $200 per month (not sure about this - they lease in the US for $185/month)

Regardless of buy or lease, the harness part will cost ~$20 each to print

Custom Boards

Jon already has the tools to prototype & build a small number (10-20) of the custom boards, but if we want to make 100's of them, we should outsource that. The labor to assemble the harness would be 1 hour if we outsource building the boards, or 2 hours if Jon builds them.

Initial Quantities

The performance team will require approximately 14 harnesses for our internal use (7 team members, 2 phones each)

The automation team requires 15 harnesses for their initial work, and possibly several hundred in the future.

Individual developers who are concerned about power usage may want a harness to allow them to develop their patches and features with low power usage impact.

Prototyping for a New Device

Each new device introduced requires several iterations of the 3D printed harness part (which has to be made to fit the case and battery with very tight tolerances). The custom ammeter board will work with any phone, and only a small daughterboard needs to be custom built for the specific phone/battery combination.

In terms of time, prototyping a battery harness for a new device will require 2-3 days of actual time, spread over a week (to allow for parts order & delivery).