LaFonera Hardware Power-Sources

From DD-WRT Wiki

Jump to: navigation, search

You are here: DD-WRT wiki mainpage / LaFonera / Hardware / Power-Sources

[edit] LaFonera voltage requirements

When connected directly to a Li-ion battery, the device draws around 550ma with wireless on and 450ma without wireless. This proves that the fonera can be powered by a single li-ion. I would suggest that someone takes 4 18650 li-ion cells and connect them in parallel to give over 8.8AH. At a discharge rate of 600ma, this should last over 14 hours.

[edit] LaFonera Battery Pack or Car-Adaptor

You can even use a LiIon battery and a stepup circuit. (or power LaFonera from the inside without the 3,3V regulator)

For those willing to take the LiIon approach, make sure you get a battery with built-in battery protection, which prevents the battery from bursting in flames (literally) when shorted, over or under-charged. It is also better to get a proper LiIon charger, which will work within the safe parameters of the battery.

[edit] How To Build a Battery Pack

To build my battery pack, I used an LM7805A, an external SCSI Zip 100 drive power adapter tip, a 9 volt battery clip, and a 9 volt battery. I soldered the positive wire from the battery clip to the input lead of the LM7805A, and the ground wire of the battery clip to the ground lead on the LM7805A. Then I soldered the sleeve of the tip to the ground of the LM7805A, and the inner hole to the output lead of the LM7805A. Then I attached a heatsink to the LM7805A to makesure it wouldn't overheat. Then I put everything into an Altoids Gum container and insulated everything with hot glue. The battery pack still gets warm, but not too bad. I can only get 10 minutes of battery life max though, so this is more of a proof of concept. [NOTE from other-party: You need a voltage regulator to dial-down the voltage to something around 6V going into the Fonera. Also, make sure you really have 8.8Ah of battery.]

NOTE: using LM7805A is not such a good ideea, as it dissipates the extra voltage in heat, so the loss of current is quite high.