GTA02 RTC backup battery

From Openmoko

Revision as of 20:02, 29 December 2010 by Glenn (Talk | contribs)

Jump to: navigation, search

RTC keeps the current time while Neo FreeRunner is off or suspended. Rechargable lithium backup battery should keep clocks running for hours when main battery is flat or removed, but it has limited lifetime.

Replace by capacitor

RTC backup battery (BAT1701: HB414-IVO1E) can be replaced by electrochemical double layer capacitor (EDLC), like XH414H-II06E (apparently obsolete, not recommended for new design) or EECEN0F204 (500 Hrs @ 60°C) (datasheet). These supercapacitors have much longer lifetime and they are less sensitive to heat from solder iron than lithium baterries.


Alternatives - untested:

(search digikey.com) ? What terminal type?:

  • DSK-3R3H224 (1000 Hrs @ 60°C)
  • KS-3R3224 (1000 Hrs @ 70°C)
  • EDLEN204 (1000 Hrs @ 85°C), Long Life - 15 years
Personal tools

RTC keeps the current time while Neo FreeRunner is off or suspended. Rechargable lithium backup battery should keep clocks running for hours when main battery is flat or removed, but it has limited lifetime.

Replace by capacitor

RTC backup battery (BAT1701: HB414-IVO1E) can be replaced by electrochemical double layer capacitor (EDLC), like XH414H-II06E (apparently obsolete, not recommended for new design) or EECEN0F204 (500 Hrs @ 60°C) (datasheet). These supercapacitors have much longer lifetime and they are less sensitive to heat from solder iron than lithium baterries.


Alternatives - untested:

(search digikey.com) ? What terminal type?:

  • DSK-3R3H224 (1000 Hrs @ 60°C)
  • KS-3R3224 (1000 Hrs @ 70°C)
  • EDLEN204 (1000 Hrs @ 85°C), Long Life - 15 years