How to Repair a Moleskine USB Book Light

25,201

15

21

About: I am interested in a wide range of things as shown in my list of interests. Almost anything creative is fun and worth trying.

Intro: How to Repair a Moleskine USB Book Light

I bought this Moleskine Rechargeable Booklight and found that it worked great until the battery went dead and then when I plugged it into a USB port to charge it showed that it was charging but no matter how long you left it charging it would not take a charge and never worked again (unless you left it plugged in).

I did a search and found that this is an extremely common problem with this particular light. Here are some product reviews on Amazon.com saying how badly this thing sucks.

I really like this booklight and so it was a serious disappointment that it has such a design flaw.

So I decided to take mine apart and figure out how to fix it. I will now show you how to fix yours.

You will need:

  1. precision screwdriver set
  2. soldering iron
  3. wire clippers
  4. double-sided tape or hot glue gun or superglue, etc.
  5. electrician's tape

The fix will cost nothing and only take about 10 minutes. This is well worth it considering how nice the booklight is and how it originally costed around $20.

Step 1: Disassembly

Pry the plastic cover off the front. You will find that it is only held on with double-sided tape.

Then use a precision screwdriver to remove the little screws so that the mechanism comes out.

Step 2: Finding the Problem

First I had to figure out what the problem was. So I plugged in the unit to a usb port and then used jumper cables to verify that the lights work when the power is being supplied to the positive and negative rails on the bottom of the mechanism.

So the problem seemed to be that the battery is not being charged. It could be due to a faulty electrical component like a burned out surface mount resistor or something blocking current from getting to the battery from the usb.

To test this hypothesis I removed the plastic from the leads on the battery and connected the jumper cables directly to the positive and negative on the battery. Note that the "charging" indicator light will not come on. After a minute or two I disconnected the jumper cables and the light worked normally. Hence the problem is power is not getting to the battery from the USB input.

Step 3: Fixing the Problem

The solution is to connect the positive of the battery directly to the positive rail coming from the USB. That way it will charge directly from the USB power without going through the internal circuitry. However, this means that the "charging" indicator light will always be on since the battery is always connected to the USB power rail. Hence we first need to cut one of the leads (it doesn't matter which one) of the blue indicator LED. You don't need this indicator LED anyway since if it is plugged in it will be charging. If you aren't sure whether it is plugged in correctly or not, just turn it on. If it works then it is plugged in right.

In the first picture I show where to cut this.

Then you have to solder the positive (red) lead from the battery to the positive USB rail. The second picture shows how to do this. A good method is to heat the insulation on the wire and then pull it apart a bit exposing bare wire, then dab a drop of solder between this and the rail below.

Step 4: Finished Soldering Job

In these pictures I show better quality closeups of the finished fix. You can see the cut LED wire and the soldered battery lead.

Step 5: Putting It Back Together

Finally use some electrician's tape to cover up the battery terminals replacing the plastic you removed earlier.

Then put it back together, and stick the cover back on with glue, or tape.

Step 6: Finished!

Now you are done! It will now charge from a USB port and it will work properly.You should only charge it for 15 minutes or 1/2 hour to get a full charge. Note: here is the lithium polymer batter that is used you will be charging it at slightly over the nomial voltage and charging current which may reduce the battery lifetime (but it is still better than a lifetime of zero which is what it had before right?) Don't charge it for longer than 1/2 hour to avoid it getting hot (although mine never got the slightest bit hot even after charging for a long period as a test).

Happy reading!

Share

    Recommendations

    • Fix It! Contest

      Fix It! Contest
    • Furniture Contest 2018

      Furniture Contest 2018
    • Tiny Home Contest

      Tiny Home Contest

    21 Discussions

    0
    None
    MarisolR13

    8 months ago

    I did it on a brand new light, it works, thank you!

    0
    None
    1o_o7

    10 months ago

    I will do an experiment and see how much power it will take.

    0
    None
    1o_o7

    10 months ago

    Point taken. I think I might do an experiment to see how much power is required to fry the battery.

    0
    None
    p_leriche

    10 months ago

    DON'T DO THIS! Bypassing the protection circuit is a fire hazard, and if your insurance company found out what you'd done you'd be on your own. The author says they left it on charge for an extended period without it getting hot. They were lucky.

    Another Instructableshows you how to replace the battery protection IC but doesn't fully resolve the question as to why these things fail in the first place.

    From that Instructable it's plain that the electronics in these things is rubbish (to put it politely). Lithium batteries are supposed to be charged according to a strict protocol, whereas this book light simply shovels electrons in until the protection IC calls foul. There are no inductors on the circuit board. A properly designed rechargeable light would contain one inductor in the charging circuit and another in the LED driver. The extra cost would be a very small fraction of the retail price.

    2 replies
    0
    None
    1o_o7p_leriche

    Reply 10 months ago

    :) First, the total energy stored in this tiny battery is practically infinitesimal. It powers an LED. So it won't start any fires by shorting it. It won't even get hot. Next, it is charged with a current limited usb port, so no 'exploding battery' youtube videos are going to be made here.

    0
    None
    p_leriche1o_o7

    Reply 10 months ago

    A USB port will deliver an amp, which is a lot for a tiny battery like that. Some people may charge it from a USB charger capable of delivering 2 Amps or more. Many people will use this as a reading light in bed and may charge it with a bedside USB charger which they also use to charge their smartphone. Bed covers provide a ready source of fuel for a fire. The energy stored in it certainly isn't "infinitesimal" - almost certainly at least as much as in a glowing cigarette end, and plenty of fires have been started by cigarette ends.

    Loads of people have got away with carelessly discarding cigarette ends, and plenty of people will get away with this, but sooner or later someone may have a very bad day! The proper thing to do is to complain loudly and publicly to Moleskine about what appears to be a nice product on the outside but apparently is rubbish inside.

    0
    None
    Gameplete

    1 year ago

    I don't know if you can edit this but I reccomend adding that you should only put on the bare minimum amount of solder. I did this and put too much on the joint which caused the battery to explode.

    0
    None
    HyattRonald

    1 year ago

    Fixed the light. Was really happy I found this as I really like the book-light. Thanks!

    0
    None
    TylerS75

    2 years ago

    Fixed! Appreciated.

    0
    None
    TylerS75

    2 years ago

    Fixed! Appreciated.

    0
    None
    TylerS75

    2 years ago

    Fixed! Appreciated.

    0
    None
    TylerS75

    2 years ago

    Fixed! Appreciated.

    0
    None
    Yuezera Sullivan

    2 years ago

    would i be able to use electric tape to connect the battery and usb instead of soldering it together? would it be a temporary fix or just as long as soldering it would? thanks

    0
    None
    AdrienneV2

    2 years ago

    Thank you!! So happy that my money isn't completely wasted!

    0
    None
    edStatic

    3 years ago on Introduction

    Thanks for looking at this and posting all the pictures. definitely very helpful. Mine was also broken so I did a little more poking around with a volt meter and can add a couple of details:

    -The positive battery terminal measured about 4 V, the negative 3.4 V - not enough potential to charge a Li battery.

    -I lifted the bottom right pin of the right-most IC (where the USB power input terminals are on the bottom of the board) and the positive battery terminal went to 2.7 V, the negative to ground. Current started flowing and the battery started charging. After a minute or two I was able to use the light on battery power.

    -My suspicion is that the IC was installed backwards. Unfortunately, I managed to break off the pin while trying to remove it, so I can't prove it.

    -Under the IC is a silkscreen saying DW01 - I'm guessing that refers to this. . I haven't managed to find the DW01 on retail electronics sites, but I may have a substitute here.

    It looks like the pinout matches up. If anybody wants to sift through all the specs they are welcome to do so.

    I will order the part and post more if I actually manage to fix it. It would be nice to have a light without losing the overvoltage protection.

    3 replies
    0
    None
    edStaticedStatic

    Reply 3 years ago on Introduction

    Whoops. Substitute link is here.

    Attention to detail. That's what makes things work when you build them.

    0
    None
    edStaticedStatic

    Reply 3 years ago on Introduction

    I finally got my parts in and had some success replacing the battery
    protection IC. Rather than hijack the whole thread I did a
    "sub-instructable" here.It seems to be working so far.

    0
    None
    1o_o7edStatic

    Reply 3 years ago

    Awesome! Thank you! If it was put in backwards at least we would finally have a reason for the flawed product.