Battery life!

[marnom]

Originally Posted by Stinger

As far as charging goes, all USB ports are pretty much the same.

In fact, they're not. Yes, they all have 5v, that is a standard for USB ports, but they do not provide all the same amount of current. A typical port will send 1000 mA, but many laptops, in order to drain less battery juice, has less current than that. And it happens that when you buy a custom case with some motherboards, there is not the same amount of current going to the front ports as there are at the rear of the computer.

[Stinger]

It's pretty clear you don't actually understand how this stuff works, at least on an electrical level. Let me try to clarify.

but they do not provide all the same amount of current. A typical port will send 1000 mA, but many laptops, in order to drain less battery juice, has less current than that.

A USB port isn't draining the battery in any way unless its under load (something is plugged into it). Even then, the device only draws the amount of juice it requires, UP TO A CERTAIN MAXIMUM, that is defined in the USB specifications. What you say about laptop manufacturers limiting the maximum current below the USB standard is just not true (provide a source if you want to prove it to me).

And it happens that when you buy a custom case with some motherboards, there is not the same amount of current going to the front ports as there are at the rear of the computer.

Again, this is simply not true. If your front ports are not able to provide the maximum current they are suppose to (USB specs), they are not working the way they should.

I've only ever seen something like this happen when someone was using a meager 250W power supply in a system that needed much more (400W+). So the whole system was just underpowered, and as a happenstance, the front USB connectors on most motherboards are pretty far down on the power line. This means that when components are fighting for juice, those connections are going to get shafted.

In any case, if your USB ports can't provide the standard maximum of 1000mA (assuming this is the correct number), something is wrong. It's never the case that they were made to use less juice.

[marnom]

I'm not saying the ports are underpowered, it does not take more than 150mA to drive data to a device. But in order to feed enough power to charge, it's not the same thing. Sorry if youo thing I don't understand how it work, I'm a computer tech and I actually manage over a 1000 workstations. What I say is that MAYBE, his usb port does not provide enough power to CHARGE the reader, not to use it and to exchange data with it.

[marnom]

http://www.zdnet.com/blog/berlind/ex...36?tag=btxcsim

[marnom]

http://www.zdnet.com/blog/apple/all-...ted-equal/1717

[Stinger]

What I say is that MAYBE, his usb port does not provide enough power to CHARGE the reader, not to use it and to exchange data with it.

I have no qualms with this statement. My issue was that you were inferring that this was the normal operating behavior of USB ports. If your USB port can't provide the current the USB specs say it should, its a problem with the port. If you have a device that needs more juice to charge than the port can provide according to those same specs, its not the fault of that port.

One of the people reading those old BLOG'S you linked understands what I mean:

The USB specification says that the maximum power that a single device should draw from a single USB port (1.1 or 2.0) is 500mA. If your device draws more than 500mA from a single port then it is the fault of the device, not the USB port!

EDIT: Did you actually read that second thing you linked or are you giving me random links based on that title?? That article has absolutely nothing to do with what we're talking about....

[marnom]

As stated in the links I provided you right before, it's not necessarily a flaw. It could be, but it could be too by design of the computer itself. Particularly with low powered netbooks. in those devices you need that kind of cable :

[marnom]

I'm sorry about the second link, that's true, I only saw the title for that one, my fault. And I think the photo I try to provide does not work but you can see what I mean on ebay:

[marnom]

http://cgi.cafr.ebay.ca/New-USB-Fema...#ht_3466wt_930

[Roy Hinkley]

Originally Posted by StealthyScribe

I was completely happy with the battery during the first week of use, but now I'm so fed up that I finally called them today.

I charged it for 3 hours last Monday (the 10th) when I first got it. The red light came on right away but I left it alone. That charge lasted until Saturday when it was down to one little tick so I decided to charge it again while it was syncing with the desktop app. Again, I left it for 3 hours and then powered it down overnight. When I turned it back on on Sunday the battery life was about 75%. Used it for a total of about 5 hours between Sunday and Wednesday, when it finally died on me last night. I left it charging overnight, but when I woke up this morning it wasn't on the "plugged in" screen it was on the "I'm reading" page, so I don't know what happened, yet my computer was still on and the device was still plugged in, so I'm not sure exactly how long it got to charge for. When I turned it on, the battery is only at 50%.

I got through to Kobo right away and the lady I spoke with said that something is definitely wrong and suggested that I try a USB wall charger. I don't have one but obviously need to go out and get one. She said that the USB wall charger might work better. If this is the case, then why doesn't the device come with one?? She said my only other option was returning the reader to them and they'd have a look at it and possibly send me another one. I don't like the idea of this option either because with my luck I'd get one that was covered in scratches or something like that.

She also said that we should be getting 8000 page turns from it, but couldn't tell me what they meant by "average use." She also confirmed that they're planning an upgrade through the desktop app this weekend.

A USB wall charger will provide more current than your PC-based USB cable. For any USB-charged device, you will find better results using a wall charger. The Kobo doesn't have one available as an option but somewhere on the website it said that one was coming soon. I presume it's something that they overlooked, or decided that including one would increase the cost of the unit.

[Stinger]

A USB wall charger will provide more current than your PC-based USB cable. For any USB-charged device, you will find better results using a wall charger. The Kobo doesn't have one available as an option but somewhere on the website it said that one was coming soon. I presume it's something that they overlooked, or decided that including one would increase the cost of the unit.

By better results, you mean strictly a faster charging time. It's not like these wall chargers will give you a bigger battery capacity or anything like that

[Roy Hinkley]

Originally Posted by Stinger

By better results, you mean strictly a faster charging time. It's not like these wall chargers will give you a bigger battery capacity or anything like that

I never said it would give you a bigger battery capacity. Of course it won't. The wall charger can provide a faster charge, but it may also provide a more complete charge, depending upon how the firmware controls the charging of the battery.

The specs on the EB-600, which, I have read that Kobo is based upon, shows battery information:

Battery: Li-Ion 3.7V, 1000 mAh, 8000 screen refresh.
Battery Charge Time: AC Adapter 4 hours, USB cable 6 hours.

I am guessing that they measured a page turn (blank the page, fetch the new page and redraw) would consue 0.125 mA. Of course, this would be with the unit doing nothing else. Every option, menu selection, download of book, navigation, etc. would all take processor power. The 8,000 page refrerence, then, would never be reached.

I wonder about replacing the 1000 mAh battery pack with a 2000 mAh pack?


http://www.netronixinc.com/datasheet.../DS-EB-600.pdf

[PeterT]

If you look at the FCC application (see post https://www.mobileread.com/forums/sho...10&postcount=6 ) it included a power supply that appears to be http://deevan.en.alibaba.com/product...r_adapter.html

DSA-6G-05 power adapter
Input Voltage: 100~240 VAC
Output Voltage: 5.0~7.5VDC , +/-5%
Output Power: 6W max
Meet CEC: Level-V

[corona]

Originally Posted by Roy Hinkley

The wall charger can provide a faster charge, but it may also provide a more complete charge, depending upon how the firmware controls the charging of the battery.

Using a wall charger isn't going to bypass firmware's control of the charging process, is it?

[StealthyScribe]

Well I left it charged for a full 9 hours while at work today using a Blackberry wall charger, just like the woman suggested to me, and the red light never came on at all. When I disconnected it the battery shows a full charge though, so I'll see how long this one keeps and update later on. I'm still really annoyed with this whole battery business and wish they weren't behaving like this for so many of us.