Nook Simple Touch Battery Replacement

[CHA-LEE]

Since most of the clubs in my USPSA section (Colorado) have moved over to the Nooks/PractiScore for match scoring I wanted to share some info about the Nook Batteries. The Nooks use a special rechargeable Lithium Ion 1250mah battery and it is pretty difficult to find direct replacements. These direct replacement batteries are fairly cheap at $10 - $15 each and I was able to find a source for them on eBay but these had to ship from China and it took over 2 months to get. While waiting for the direct replacement batteries I found another source for a slightly different size Lithium Ion 1800mah battery that did not have the special plug or circuit board used on the Nook battery. I was able to move the special plug and circuit board from the old Nook battery over to the 1800mah battery successfully with a little bit of soldering. These alternate 1800mah batteries are available here in the US and are about $7 each so you can get them right away. I have listed a direct link to the 1800mah battery where I ordered them. They shipped quickly and what I got was exactly what I expected so I am giving this vendor a thumbs up.

http://www.batteryspace.com/polymerli-ioncell37v1800mah425085-2c67wh36arate-ullisted.aspx

I know that each USPSA club may not have an electronics/technical person that would be able to rework these 1800mah batteries so I am offering my assistance in doing this type of rework. If you guys have Nooks with dead or weak batteries I can provide assistance in replacing the batteries. I will not charge anything for the labor of reworking the batteries but I will expect that the clubs pay for the replacement batteries and whatever shipping charges there are to get them back to you. Given how cheap these replacement batteries are and the opportunity to increase the capacity by 50% with using an 1800mah version it would probably make sense to proactively replace the batteries on an annual basis.

From a between match storage perspective I have found that its best to turn off the Wireless then plug it into the USB charger. Then fully power off the Nook and leave it plugged in until the next match. Doing this eliminates the trickle discharge of the battery and keeps the Nooks fully charged all the time which helps increase the life span of the battery. Don't worry about over charging the batteries as the charging circuit will turn on and off automatically depending on the charge level of the battery. It’s not possible to over charge the batteries. What will kill the Nook batteries is allowing them to become excessively discharged. If you allow a Lithium Ion battery to become fully discharged, there is a good chance that it will become ruined and never take a charge again, thus needing to be replaced.

If you guys want some training on how to disassemble the Nook let me know. They are very easy to take apart and it usually takes less than a minute to get it disassembled to the point where you can access the battery.

I am basically thinking of a process where you disassemble your Nook and remove the battery, then ship the bad battery to me for rework/replacement. If you guys feel adventurous and want to replace the batteries on your own I can give you some tips on doing the rework process.

Hopefully this is helpful information. If you have any questions let me know.

[jcwren]

Interesting that you've had to replace batteries. We have NOOKs that about 2 years old with regular weekly and monthly use that still have in excess of a 75% charge at the end of a six hour match.

Nice that you found a supply of compatible batteries that will work, even if a little soldering is required. One thing to note, the battery gauge will likely be inaccurate for some number of charge cycles if the battery is replaced. The BQ27510 charger has to develop a profile of the battery to accurately report percentage charged, time remaining, etc. So just be aware that 100% charged may not be right for a while.

I still *strongly* disagree with you about keeping the NOOK on the charger all the time, for several reasons. One is that it increases the susceptibility of the NOOKs to be killed by a lightning strike. Feel free to use all the power-protection strips you like, but when you have $900 (retail) worth of NOOKs plugged in, that protection still isn't worth it to me. It's easier to unplug it. The second is that yes, the battery charger *does* cycle on and off. Charging at any level generates heat, and heat is detrimental to the batteries. And the NOOKs can sit for *months* in a turned-off state without discharging the batteries below the point where it won't boot. Charge them a few hours or the evening before the match.

On rare occasions, I've seen NOOKs get confused, where the screen behaves oddly, the real-time clock is off and a few other oddities (maybe 4 times out of 33 NOOKs over 18 months). For all of these, disconnecting the battery for about 10 minutes, and then re-installing it fixed the issues.

Here's some light reading: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

According to /sys/devices/platform/i2c_omap.2/i2c-adapter/i2c-2/2-0055/power_supply/bq27510-0 (the interface in the Android system for the BQ27510 charger), the battery is charged to 4.18V at full charge. This is important in light of the statement from the above source, "Besides selecting the best-suited voltage thresholds for a given application, Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. When fully charged, remove the battery and allow to voltage to revert to a more natural level like relaxing after exercise. Although a properly functioning Li-ion charger will terminate charge when the battery is full, some chargers apply a topping charge if the battery terminal voltage drops to a given level."

[CHA-LEE]

Good info to add to the discussion. Worry about lightning strikes is a valid concern so keeping them connected may not be the best idea. Worrying about the “Heat” produced while charging or remaining connected after its fully charged is not a concern. The batteries never get above 90 deg F while charging (regardless of charge/discharge condition) and that is still well within acceptable heat tolerances for a long lasting life for the battery. Its far more probable to push the batteries into an over temp condition at a match by setting the Nook out in the sun on a hot summer day for an extended amount of time. Keep them in the shade when not in use to keep from cooking the batteries at the range.

Overall, the battery life has been excellent on most of the Nooks we have in our section. We had one club that left all of their Nooks turned on with the wireless turned on for over 2 months and it completely killed the batteries in all of their Nooks. That is when I started the process of finding replacement batteries, rework process and finding alternatives.

Hopefully the batteries in the Nooks outlast the life of the Nook its self. But if it doesn’t we at least have a cheap way of replacing the batteries so we can keep the Nook’s in service.

From a battery use/consumption perspective, my observation is that when the wireless is turned on it eats up the battery a LOT faster than having the wireless is turned off. So if you are diligent in simply turning off the wireless after you use it then you will probably not run into any low or dead battery issues.

[wgnoyes]

...

I still *strongly* disagree with you about keeping the NOOK on the charger all the time, for several reasons..... The second is that yes, the battery charger *does* cycle on and off. Charging at any level generates heat, and heat is detrimental to the batteries. And the NOOKs can sit for *months* in a turned-off state without discharging the batteries below the point where it won't boot. Charge them a few hours or the evening before the match.

...

I could guess that's probably why cha-lee is experiencing battery issues. Just let them sit turned off and unplugged. Then the night before the match, plug them all in until the little lights turn green and you're ready to go.

...

From a battery use/consumption perspective, my observation is that when the wireless is turned on it eats up the battery a LOT faster than having the wireless is turned off. So if you are diligent in simply turning off the wireless after you use it then you will probably not run into any low or dead battery issues.

Mine run with wifi turned on all day long (they wouldn't be much good for a match if they couldn't!) and still only use about one-quarter of the total charge in the battery according to the display. I've got some here that I haven't used in 6 weeks since the last match and have been re-rooting a few of them, and they come up saying they're about 80% charged after sitting for that long. Even one sitting in standby mode for weeks on end that had wifi on when it went to sleep shows 60% or so.

[CHA-LEE]

Just for the record. The Nooks I am in charge of babysitting were not treated well before I got them. Most of them were left unplugged for a long time allowing the batteries to get excessively discharged and the batteries were hurt by this. From what I can see in how the batteries perform they are only about 50% of their peak potential. I am going to be upgrading all of my clubs Nooks to the 1800mah battery and hopefully this puts the battery issues we have been experiencing behind us.

Edited September 19, 2013 by CHA-LEE

[Mark R]

cha-lee...I'd like to know the trick of opening up a Nook...I had one go bad and tried, but completely tore it up trying. No loss since it was a refurb.

[CHA-LEE]

cha-lee...I'd like to know the trick of opening up a Nook...I had one go bad and tried, but completely tore it up trying. No loss since it was a refurb.

Mark> Check out the below thread I started for Nook Troubleshooting and Tips. The second post has a video showing the step by step process of disassembling the Nook.

http://www.brianenos.com/forums/index.php?showtopic=165469

[Mark R]

cha-lee...I'd like to know the trick of opening up a Nook...I had one go bad and tried, but completely tore it up trying. No loss since it was a refurb.

Mark> Check out the below thread I started for Nook Troubleshooting and Tips. The second post has a video showing the step by step process of disassembling the Nook.

http://www.brianenos.com/forums/index.php?showtopic=165469

Thanks...I'll take a look.