This morning when I asked my wife about her book, she told me the batteries in her Book Courier were low. According to the machine they were still registering 30 per cent. Nevertheless, in view of recent postings on the list, I went ahead and changed the batteries. Best. Robert. ----- Original Message ----- From: "Darren Brewer" <darren.m.brewer@xxxxxxxxxxxxxxxx> To: <bookcourier@xxxxxxxxxxxxx> Sent: Sunday, June 05, 2005 3:52 PM Subject: [bookcourier] Re: Sapping batteries - a helpful warning The thing to remember when measuring the voltage on batteries is that the voltage level can be quite different if the battery is not actually powering anything when measured. When the battery voltage is measured and it is not powering anything it is said to be off load. But when inserted into a piece of electronics and current is being drawn the battery is then said to be loaded and the voltage level can significantally drop. The only accurate way to measure the voltage of a battery is to measure it whilst it is loaded. So for instance the courier may report the battery as being low and needing changing. But after you take the battery ou and take a measurement. It is then off load. The voltage may be measured at, say 1.2 volts. It may appear that it is ok when in fact if measured whilst in the courier it could go down to 1 volt or less. These are not actual values I have measured I'm just giving an example of how the voltage level can change when a battery is in use. The battery level circuit will monitor the voltage of the batteries whilst they are powering the courier and they will indicate when the voltage level falls below a certain value. I don't know what this is but obviously from what I've just said the voltage level will go up once they are removed and off load. Different electronic gagets will use different amounts of current and this determines how much the voltage will drop. The more current drawn the lower the voltage on the battery. Darren. ----- Original Message ----- From: "George Bell" <george@xxxxxxxxxxxxxxxxxxx> To: <bookcourier@xxxxxxxxxxxxx> Sent: Wednesday, June 01, 2005 12:14 AM Subject: [bookcourier] Re: Sapping batteries - a helpful warning Hi Greg, Your battery experience is not exclusive to the BookCourier by any means. Times without number I have checked discarded batteries my wife has "thrown out" only to find they appear to have an acceptable voltage. However, at the end of the day, "Ohms Law" states that Volts time Amps equals watts. I'll spare the science here, other than to confirm what someone earlier that it is better to go for the 2500 mAh type batteries which are designed to provide a higher level of power, but for lower power devices such as the BC, result in a longer period of use. George. -----Original Message----- From: bookcourier-bounce@xxxxxxxxxxxxx [mailto:bookcourier-bounce@xxxxxxxxxxxxx] On Behalf Of Greg Epley Sent: 31 May 2005 20:07 To: bookcourier@xxxxxxxxxxxxx Subject: [bookcourier] Sapping batteries - a helpful warning Hello everyone, In hopes of preventing anyone else from going through this same issue, I have a helpful note to pass along. Some preliminary explanation is necessary first, so please bear with me. Explanation: Years ago, I can remember frequently using AA alkaline batteries down to around 0.8 volts before I ended up having to toss them. This was perhaps because devices like toys were different from today's electronic devices; perhaps it was the motors or the fairly low power LED's many devices used then; I'm not sure about exactly what the difference was. Anyway, I know the GP alkalines supplied with my BC when I got it in late March 2005 were full capacity because they were checked on a meter; also, the BC reported them at 100%. Around the 22nd of May 2005, the BC finally reported the low battery warning. Not realizing that today's devices don't seem to use all the possible power in alkalines that they used to, I wanted to get the max out of my alkalines. It was late at night and I was trying to finish a certain portion of a book so I just went through the change battery procedure and set the supposedly dead batteries aside to check on a meter the next morning. =20 It has been my experience in the past that AA alkalines do not recover any significant amount of power when left overnight; that is to say they aren't 0.6 volts or something and then by morning they are 1.2 volts, just as an example. Perhaps alkaline battery technology has changed over the years and it just passed me by somewhere along the way, I don't know. Anyway, the next morning I checked the supposedly dead batteries and they registered 1.23 volts each. A brand new alkaline battery will generally register 1.6 volts, plus or minus .05 volts, so I consider 1.23 volts to be sufficient energy to run a device with no moving parts, such as the BC. Understandably that was not a very scientifically based conclusion, but it does have a certain amount of logical sense to it anyway, unless one is perhaps very skilled in electronics and knows more than most consumers. Anyway, I went through another change battery procedure on the BC and inserted the supposedly dead batteries;=20 the BC registered them at 42%, so I figured great, I can get a little more use out of them. That night, I ran for about 18 minutes before the BC said the batteries were low; I immediately checked the batteries on the BC and it said 14%. Again, I was busy listening to something so I just went through the change battery procedure and put the new batteries back in and finished out my session, setting the supposedly dead batteries aside to check in the morning. Next morning, the supposedly dead batteries registered at 1.22 bolts. This was weird; I'd never seen batteries, especially alkalines, recover like this on power when left overnight. So, I figured I'd just change them again and run them down a little further. Upon inserting the supposedly dead batteries in the BC, it registered them at 40%. That night, I was listening to a book when the BC suddenly said the batteries were low; I don't know how long I'd been listening because the whole night went downhill from there. I quickly tried to get the BC to tell me the level, but don't recall now what it said. I initiated the change battery procedure, but when I inserted the fresh batteries, the BC was dead. I couldn't get it to talk at all. I tried a reset procedure - no change. I tried everything I could think of for a half hour and finally went to bed. The next morning, I checked the supposedly dead batteries and the meter registered them at 1.1 volts. The fresh battereies in the BC registered at 1.55 volts. I again worked for about a half hour with no results on the BC talking; I tried different CF cards - nothing - nothing worked. I left the BC with no batteries or CF card for the better part of a day and again, no change - nothing worked, it was just dead. Springer is currently working on my BC and I'm thankful for that. I have since learned that alkaline batteries apparently have an effect whereby they reflect what seems to be a good strong charge, but in actuality the level plumments rapidly when the batteries are back in use. This accounts for the recovery in charge level I experienced. I wish I'd taken the time now to check the batteries as soon as the BC said they were low, just out of pure curiosity to see what the meter said, but I didn't. Of course, there's a possibility the meter would still report the charge level higher than it actually is when the batteries are in use, so I don't know how much good it would have done to check them. Springer also said that the BC probably went into this "coma" (my word not theirs) because the change battery procedure didn't complete its cycle due to the power loss of the batteries, and while they admit some form of alternate power some some sort would have likely prevented the problem, of course we all know that kind of hardware modification isn't currently on the drawing board at Springer. Keeping that in mind then, what I've learned from this experience is that when your BC says the batteries are low - initiate a change battery procedure ASAP. If you can't change them, leave the BC off until you can - do not under any circumstances do what I did and do anything that saps enough charge out of the batteries to the point that the change battery procedure could fail like this, or you'll most likely end up with a dead BC too. I don't know what exactly Springer does to "fix" the problem, but to me it would be nice if there were one of those internal reset switches activated by inserting a paper clip tip into a small hold on the BC to do some kind of hardware reset that didn't involve sending the BC in for a fix by Springer. Perhaps that's something Springer will consider for a future BC. I don't even know if such a reset would fix the problem. Anyway, my apologies for this very long post, but I wanted to be thorough in trying to explain and warn other BC users away from sapping batteries down too low. -Greg =0AThis Message has been scanned for viruses by McAfee Groupshield.