Rockbox mail archiveSubject: Re: Trickle Charging
Re: Trickle Charging
From: Uwe Freese <mail_at_uwe-freese.de>
Date: Tue, 10 Dec 2002 11:45:43 +0100
Björn Stenberg wrote on Monday, December 9, 2002, 10:05:40 PM:
BS> Being the project Charger Guru, are you planning on adding some type
BS> of trickle charging to the code?
I hadn't planned it yet, but I can do it if you like.
BS> There is currently a problem with charging the Archos overnight. If
BS> the batteries get full at 4am, the unit will stay turned on and
BS> consume batteries for a number of hours until I wake up and unplug
BS> it. Thie is especially a problem if the Deep Discharge option is
BS> Would it be feasible to add a small trickle charge that offsets this
BS> so that the batteries remain full in the morning?
Before starting to write code, I have some questions about the design.
My first thought was:
- charger on if voltage < a
- charger off if voltage > b (with b a little bit smaller than the max
voltage of the last complete charge cycle)
But this has a disadvantage: The batteries are not equally full the
whole time. It depends on when you plug off the charger if your
batteries are completely full or not.
So now I think of this:
Charging on means charging with ~300 mA, charger off means decharging
So start charging at intervals 15 sec (charge) - 45 sec (decharge) (or is
this what you call trickle charge?).
Check the voltage every minute and adjust the values. E.g. if the
voltage is too low, charge 16 s and decharge 44 s.
I think this should work very well and keep the batteries full.
However, the feature should be configurable (on/off), because this is
not good when using the player all the time plugged in.
Another possibility is to only enable it when deep discharge is off. Or
- start trickle charge after a complete charge cycle if deep discharge
- stop trickle charge after 12h, because charging over a long time is
not good for the batteries
So please comment these ideas. I'll then implement and test it. I think
it will be finished at the weekend.
Received on 2002-12-10