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Robert Hak019203b2002-08-21 10:36:05 +00001Q1: Are my batteries charged all the time when connected to my Player/Recorder?
2A1: Player: the charging is all done by hardware and the exact
3 functionality is hard to determine. It is however not recommended to keep
4 the charger connected for more than 10-15 hours if you're not using the
5 unit.
6
7 Recorder: no. The charging algorithm is carefully crafted in to not wear
8 out the batteries any more than necessary. If you're using your unit
9 connected to the charger most of the time, use the 'deep discharge' option
10 to save your batteries somewhat.
11
12Q2: Will keeping my charger connected a long time damage my batteries? Can I
13 leave it over night?
Uwe Freeseeec501e2002-12-14 13:03:14 +000014A2: There's a deep discharge mode and you can switch trickle charge on and off.
15 If you use your AJB connected to the power supply the whole time, select
16 "deep discharge on" and "trickle charge off". If you want to charge your
17 AJB over night and take it with you the next day, select "deep discharge
18 off" (that it starts charging immediately) and "trickle charge on"
19 (that the batteries remain full).
20
21 Trickle charge is needed to keep the batteries full. That's necessary because
22 the device will stay powered on and continue to consume some power from
23 the batteries (the hardware does not allow running from the charger
24 without charging batteries, or powering off with the charger connected).
25 The trickle charge time is 12 hours. It should be enough for you to disconnect
26 your AJB in this time and turn it off / use it.
27 However, after 12 hours of trickle charge, it will turn it off, the batteries
28 are discharged and another charge cycle is started.
Robert Hak019203b2002-08-21 10:36:05 +000029
30 As the Battery FAQ at http://www.greenbatteries.com/ puts it:
31 "A NiMH battery can be charged and discharged hundreds of times,
32 but whether that means 200 times or 800 times has a lot to do
33 with how (you use it)".
34
35Q3: Does Rockbox charge the batteries more/less/worse/better than the Archos
36 firmware?
37A3: Player: Rockbox doesn't affect the charging on Players, it is all done
38 by hardware logic out of software control.
39
Uwe Freeseeec501e2002-12-14 13:03:14 +000040 Recorder: The whole algorithm is made to carefully charge the batteries full
41 and keep them full after that with a trickle charge option. Many documents
42 about charge ICs were considered. If you want to know details, then look
43 into docs/CHARGING_ALGORITHM. If you have comments, write to
44 mail@uwe-freese.de or the Rockbox mailinglist.
45
46 Test results with trickle charge (battery capacities measured with an
47 external charger, Model "Conrad Electronic Charge Manager 2010", ~100 EUR):
48
49 - after normal charge and top off time: 1798, 1834, 1819, 1815 mAh
50 - after normal + top off + trickle charge (12h): 1784, 1748, 1738, 1752 mAh
51 - charged with external charger: 1786, 1819, 1802, 1802 mAh
Robert Hak019203b2002-08-21 10:36:05 +000052
Uwe Freeseeec501e2002-12-14 13:03:14 +000053 You can see, whenever you take your AJB with you in the 12h trickle charge
54 period, the batteries are at least 97% full. :)
55
Robert Hak019203b2002-08-21 10:36:05 +000056Q4: What kind of batteries are there in my factory default Player/Recorder?
Justin Heiner1be02f62002-09-04 02:05:53 +000057A4: Both ship with 1500 mAh NiMH (Nickel Metal Hydride) batteries.
Robert Hak019203b2002-08-21 10:36:05 +000058
59Q5: Is it hard to change the batteries? Does it void my warranty?
Heikki Hannikainen221c4a22002-09-06 05:42:23 +000060A5: It is not very hard - the Archos manual and the FAQ on their web site
61 describe how to do it. Their technical support confirmed that
62 replacing the batteries with NiMH cells (of different capacities)
63 will not void the warranty. Just don't remove the screws.
64
65 Some units have been shipped with two sets of batteries, my Recorder 20
66 only had one set. Someone actually had Archos send him new batteries
67 free of charge after they had weared out, under the warranty.
Robert Hak019203b2002-08-21 10:36:05 +000068
69Q6: How much do replacement batteries cost? Where can I buy them?
70A6: http://www.greenbatteries.com sells 1800 mAh NiMH cells at $3.25USD each,
71 and I bought 4 of the same GP batteries for 20 euros in an home
72 electronics & household appliance store in Finland. NiMH batteries are
73 sold in almost all shops that sell consumer electronics, and in many
Heikki Hannikainen5dbd4d12002-08-21 12:43:57 +000074 online shops. Browse around. There's a pretty good comparison between
75 different battery makes and models at the digital imaging resource site:
76 http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM
Uwe Freeseeec501e2002-12-14 13:03:14 +000077 In Germany, www.reichelt.de sells GP 2000 batteries for 2,75 EUR (12/2002).
Robert Hak019203b2002-08-21 10:36:05 +000078
79Q7: What kind of run-time can I expect on a set of fully-charged batteries
80 when running Rockbox?
81A7: For the stock 1500 mAh cells, from 6 hours to 8 hours, depending on
Uwe Freese9d5eab32003-04-27 11:09:37 +000082 which charger was used (see Q3) and the bitrate you use (higher bitrate
83 means more harddisk runtime). It depends a lot on the condition of the
Uwe Freeseeec501e2002-12-14 13:03:14 +000084 batteries. With 2000 mAh batteries, you should reach about 10 hours or more.
85 We are looking into implementing more battery-saving techniques in rockbox
86 to make it rock longer.
Uwe Freese9d5eab32003-04-27 11:09:37 +000087 If you have a modified AJB with 8 MB, you can reach playing times of up to
88 16 hours with 2100 mAh batteries.
Robert Hak019203b2002-08-21 10:36:05 +000089
Heikki Hannikainen1198d372002-08-29 06:34:03 +000090Q8: Can I use different batteries in my Archos? How much playtime would
91 I gain by using 1800 mAh batteries instead of the 1500 mAh ones?
Robert Hak019203b2002-08-21 10:36:05 +000092A8: Only use NiMH-type rechargeable batteries. It is considered to be safe
93 to use NiMH batteries of different capacities though, a lot of people
94 have purchaced 1700 or 1800 mAh batteries to replace the stock 1500 mAh
Heikki Hannikainen1198d372002-08-29 06:34:03 +000095 cells and have the device run a bit longer. 2000 mAh batteries are
96 just appearing in shops are equally good to use.
97
98 In theory, running time = capacity of batteries / current drawn by device,
99 so running time should increase linearly by the capacity, and 2000 mAh
100 over 1500 mAh should give 33% longer running time. In practice, the
101 mAh ratings are more or less tuned up by the marketing department
102 (think of watts on the back of "hi-fi" speakers and amplifiers) and
103 what you actually get out of the cells is something else than what is
104 printed on them. Check the excellent imaging-resource link above for
105 details!
Robert Hak019203b2002-08-21 10:36:05 +0000106
107Q9: Can I use non-chargeable batteries in my Archos?
108A9: This is not recommended. The unit has been designed to operate with
109 four 1.2V batteries producing about 4.8V at most, and using 1.5V
110 alkaline/zinc carbon batteries will produce around 6.0V, which will
111 heat up the unit a lot more and might even damage it. The Archos
112 manual explicitly tells you not to do so.
Linus Nielsen Feltzingac8ca792002-08-27 09:55:57 +0000113 Also, if you connect the charger, it may even destroy both the batteries
114 and the unit.
Robert Hak019203b2002-08-21 10:36:05 +0000115
116Q10: Can I use a different charger?
Heikki Hannikainen1198d372002-08-29 06:34:03 +0000117A10: The short answer is: Using a different charger will void your warranty
118 and can be dangerous to your unit, so we can not recommend it.
119
120 On the other hand, people have successfully used different chargers
121 with similar specifications as the stock charger. The charger must
122 have the same kind of connector with same polarity (center positive/+).
Robert Hak019203b2002-08-21 10:36:05 +0000123 The charger should supply at least 7-8 volts, and if it provides
Uwe Freesec9743e22002-12-10 23:14:04 +0000124 more than 10V, it probably should be regulated to 10V (do not
Robert Hak019203b2002-08-21 10:36:05 +0000125 directly plug it in your 12V car battery or it's charger!).
Heikki Hannikainened048722002-08-21 20:54:20 +0000126 The universal travel charger sold by Archos is specified at
127 12V, 1.2A so that's probably the maximum rating you should use.
Heikki Hannikainen1198d372002-08-29 06:34:03 +0000128 A good circuit for powering from a car battery or other source
Uwe Freesec9743e22002-12-10 23:14:04 +0000129 with a higher voltage would be a 600 mA fuse and a 10V regulator like
130 a 7810 of your favourite manufacturer in series.
Robert Hak019203b2002-08-21 10:36:05 +0000131
Heikki Hannikainen1198d372002-08-29 06:34:03 +0000132 Inside the Jukebox there is a regulator which limits the charging
Uwe Freesec9743e22002-12-10 23:14:04 +0000133 current applied to the batteries. The higher the input voltage, the hotter
134 this IC gets. Don't use an input voltage above 12V.
135 Using lower charging voltage < 10V will slow down the charging. But the
136 rockbox charging algorithm should work then, too.
137
138 These are the output voltages of an original archos power supply:
139 - connected to AJB Recorder, not charging: 13,7 Volt
140 - connected to AJB Recorder, charging: going down to 10,4 Volt
141
142 Here is how changing the input voltage changes the charging current:
143
Björn Stenberg6ebf5e42002-12-16 12:36:21 +0000144 voltage charging current (limited only by the AJB)
145 ------------------------------------------------------
146 7,0V 10 mA
147 7,5V 30 mA
148 8,0V 50 mA
149 8,5V 70 mA
150 9,0V 140 mA
151 9,5V 250 mA
152 10,0V 330 mA
153 10,5V 350 mA
154 11,0V 350 mA
155 11,5V 350 mA
156 12,0V 350 mA
Uwe Freesec9743e22002-12-10 23:14:04 +0000157
158 To summarize:
159
Björn Stenberg6ebf5e42002-12-16 12:36:21 +0000160 - do not use an input voltage > 12V (it will only heat up the regulator)
161 - optimal input voltage is 10V (regulated)
162 - use a fuse of ~600mA
163 - using a different charger voids your warrenty
Robert Hak019203b2002-08-21 10:36:05 +0000164
165 Many people are happy using an external quick charger which
Heikki Hannikainen1198d372002-08-29 06:34:03 +0000166 is specified to work with NiMH batteries. This is completely safe
167 and will not void your warranty.
Robert Hak019203b2002-08-21 10:36:05 +0000168
169Q11: Can I buy a replacement charger exactly as the one Archos shipped?
170A11: The FAQ on the Archos web site and the top of the charger both read:
171
172 Output: 9VDC 600mA
173 Center positive (+) polarity
Heikki Hannikainened048722002-08-21 20:54:20 +0000174
175 The universal travel charger sold separately on the Archos web site
176 is specified for 12VDC, 1200mA output.
177
Robert Hak019203b2002-08-21 10:36:05 +0000178 Chargers with similar (or user-adjustable) properties are available
179 at shops selling consumer electronics.
180
Robert Hak019203b2002-08-21 10:36:05 +0000181Q12: I often need to stop my player for about 15 minutes or so, and when I do
182 it runs off it's batteries. I was wondering, which is best: shutting the
183 player down completely and rebooting it when I want to listen again, or
184 leaving the unit on? Which way does it draw more power?
185A12: In our testing we found the following results:
Björn Stenberg6ebf5e42002-12-16 12:36:21 +0000186 HDD off, backlight off, idle 94 mA
187 HDD off, backlight off, play 97 mA
188 HDD off, backlight on, idle 129 mA
189 HDD off, backlight on, play 131 mA
190 HDD on, backlight on, play 230 mA
191 HD on, reading, backlight off ~ 600 mA
Robert Hak019203b2002-08-21 10:36:05 +0000192 HD spin up before read max 800 mA
Björn Stenberg6ebf5e42002-12-16 12:36:21 +0000193
Björn Stenberg313c8252003-04-23 11:52:01 +0000194 Using the power draw measurements shown above, lets look at the numbers:
195 Power-down and restart vs. paused for 15 minutes.:
196
197 Pause for 15 minutes will draw: 94 mA / 60 minutes * 15 minutes =
198 23.5 mAh.
199
200 Power-down and restart will draw about (800mA / 3600 seconds * 3
201 seconds = 0.6666 mAh) + (600 mA / 3600 seconds * 6 seconds = 1.0 mAh) +
202 (230 mA / 3600 seconds * 8 seconds = 0.5111 mAh) = 2.18 mAh total used.
203
204 Thus, leaving it paused for 15 minutes draws more power (23.5 mAh) than
205 turning off and then on again (2.18 mAh).
206
207 So where is the break-even point?
208
209 Each second of pause will draw about 94 mAh / 3600 seconds = 26 µAh.
210
211 2.18 mAh / 26 µAh = 2180 µAh / 26 µAh = 83.5 seconds
212
213 Thus a shutdown and restart uses as much power as 83.5 seconds of pause.
Heikki Hannikainen002c4a42002-08-21 12:27:02 +0000214
Daniel Stenberg1436b102002-08-27 11:59:01 +0000215Q13: When I plug in the charger when the Recorder is turned off, it turns
216 itself on and starts charging in the Archos software? What's up?
Heikki Hannikainen002c4a42002-08-21 12:27:02 +0000217A13: There is a switch in the DC IN jack of the Jukebox - when a charger (or
218 whatever) is plugged in, the unit is powered on, even if the charger
219 is not plugged in a mains outlet.
220
221 If the charger is providing power at this point, the Archos firmware
222 located on the FLASH ROM does not load a new firmware version (like
223 Rockbox) from the disk, but goes into charging mode instead. You can
224 use this feature to get to the Archos charger if you want to.
Daniel Stenberg1436b102002-08-27 11:59:01 +0000225
226Q14: When I plug the charger in my Recorder, it doesn't immediately start
227 charging the batteries!
228A14: When Rockbox is running on the Recorder (the device has been booted
Heikki Hannikainen002c4a42002-08-21 12:27:02 +0000229 without the charger) it's power management code runs once per minute
230 (thus the charge level and charging status is only updated every minute).
231 If the battery is not full, it will start charging. If the 'deep
232 discharge' mode is enabled in the settings menu, it will start charging
233 only when the battery is almost empty.
Heikki Hannikainen1198d372002-08-29 06:34:03 +0000234
235Q15: What about the memory effect? Should I be worried about it or not?
236A15: That depends on who you ask. ;-) NiMH sellers say NiMHs are better and
237 do not have a memory effect, but the usual opinion seems to be that
238 they do, although it is very small.
239
240 However, if you use your AJB connected to the charger all the time,
241 we recommend you to use the deep discharge option.
Uwe Freese5defb4c2003-01-15 14:53:15 +0000242
243Q16: When I start my Jukebox, (dis)connect the charger and browse through the
244 directories, the battery level changes a little bit. Sometimes it's even
245 going up without the charger is connected! What's wrong?
246A16: Nothing's wrong. The battery level is calculated out of the voltage.
247 Because disk spinning, LED backlight, charger all influence the actual
248 battery voltage, it is usual that the battery level is going a little bit
249 up and down sometimes. This cannot be avoided although we tried to make the
250 battery level display as little confusing as we could.
Uwe Freese9d5eab32003-04-27 11:09:37 +0000251
252Q17: My batteries are at 92%, the charger is connected to my recorder, deep
253 discharge is off. But charging doesn't start. What's wrong?
254A17: Charging starts if the battery level is below 85%. This is because
255 charging batteries that *are* already more or less full is not good for
256 the batteries and the end of the charging cycle can't be detected safely.
257 So it's better to start at a level at least as low as 85%.
258 If you want to have full batteries in the morning, leave the charger
259 connected over night. Charging will then start some hours later. The
260 second possibility: Use the Archos charging algorithm. At least,
261 your batteries will be full one more time. ;-)