MobileRead Forums - View Single Post - Recommendation for 'easy to replace' battery e-ink e-reader

kacir · 10-05-2011, 06:38 AM

When I go camping with my reader I use small light powered from a 6V lead acid battery like this http://www.batteryprice.com/bp12-66v...battery_1.aspx

You can have a small circuit that would convert 6V from the Lead Acid battery to 5.2V needed to charge the reader (*). With 12Ah 6V battery you can power your reader and s small LED light for quite a few evenings.

12Ah 6V battery weighs about 2kg (3.4lbs)

Led flash light (torch) that you can charge by turning a crank is also a very good idea. But the locals will have some solution for light, such as candles, kerosene lamps, ...

(*) For the simplest solution you can connect one or more diodes in series (an ordinary diode drops tension by 0.7V). When the battery gets depleted, you bypass diodes one by one using dip switches. Remember, that fully charged "6V" battery has in fact 7.24V ;-)
Or you can get 12 volt battery and use Buck step-down DC-DC converter (http://en.wikipedia.org/wiki/Buck_converter). The simplest versions of such converters are chargers powered from car lighter charger. Make sure to pick up electronic charger. Electronic chargers (step-down DC-DC buck converters) have relatively large range of input voltages, such as 6 - 24V.

10-05-2011, 06:38 AM	#8
kacir Wizard Posts: 3,450 Karma: 10484861 Join Date: May 2006 Device: PocketBook 360, before it was Sony Reader, cassiopeia A-20	When I go camping with my reader I use small light powered from a 6V lead acid battery like this http://www.batteryprice.com/bp12-66v...battery_1.aspx You can have a small circuit that would convert 6V from the Lead Acid battery to 5.2V needed to charge the reader (). With 12Ah 6V battery you can power your reader and s small LED light for quite a few evenings. 12Ah 6V battery weighs about 2kg (3.4lbs) Led flash light (torch) that you can charge by turning a crank is also a very good idea. But the locals will have some solution for light, such as candles, kerosene lamps, ... () For the simplest solution you can connect one or more diodes in series (an ordinary diode drops tension by 0.7V). When the battery gets depleted, you bypass diodes one by one using dip switches. Remember, that fully charged "6V" battery has in fact 7.24V ;-) Or you can get 12 volt battery and use Buck step-down DC-DC converter (http://en.wikipedia.org/wiki/Buck_converter). The simplest versions of such converters are chargers powered from car lighter charger. Make sure to pick up electronic charger. Electronic chargers (step-down DC-DC buck converters) have relatively large range of input voltages, such as 6 - 24V. Last edited by kacir; 10-05-2011 at 06:40 AM.