Li-ion power mod

Re: Li-ion power mod

Postby snapper » Thu Mar 29, 2018 3:14 am

Diabolo wrote:Hello,

For people who want to simplify their lives, there is this:
- ... 0011.m1850


hi folks,
found this on thingiverse, a kind australian has provided this for diy 3D printing.
the beveled housing makes it easier to read as a tabletop device :lol:
there is enough space for two 18650 LiIon cells and charger equipment e.g.,
if you switch them to 7.4V in series not need a stepup converter and have a clean supply voltage :D

cheep Charger Cable and Lipo capacity indicators found here --->*/32647825736.html........*/32842555678.html
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Re: Li-ion power mod

Postby OhioEngineer » Tue Apr 10, 2018 3:04 pm

Dear Colleagues,
With so many posts about the inconvenience with 9V supply and work-around battery solutions, may I suggest next rev of the DSO Shell has a micro USB connector instead of 9V coax.
This should support BOTH 5V DC IN AND USB DATA

1. Thew scope now uses external USB 5V power like most other portable devices. There is plenty low cost support by cables, power banks etc..
2. The kit could now include a Li battery (could be option if it causes cost / shipment issues)
3. The easy USB data interface will now allow a wealth of expanded analysis and reporting in a PC or tablet.
4. The unique 12-bit resolution offers advantages and flexibility at a large screen display. On a small screen you can't see the difference to 8-bit.

- I modifed my own unit internally with a 1- dollar DC up-converter MT3608 board, adj to 9.3V, added in/out pi filters and glued micro USB 5v in connector to the main board. No noise!
And I put a small 5V USB power bank +double stick tape on backside cover top, now creating a convenient tilt of the display. Much easier to read !
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Re: Li-ion power mod

Postby Zimphire » Wed May 09, 2018 3:54 am

You can now buy 9v Li-On batteries that has a USB port built in for charging.
Just gut one (comes wth charging/protection board) and install it into the debice. No step-ip circuit needed. This is what I am about to do.
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Joined: Sat Nov 04, 2017 9:30 am

Re: Li-ion power mod

Postby tomtom38 » Sat Jul 21, 2018 4:40 pm

can I use every LI ion Battery or only which have two connections plus and ground
mobile phone batterys have often three or four connections can I use them too?
Or have anyone examples for Batterys
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Re: Li-ion power mod

Postby upsss » Sat Jul 21, 2018 5:50 pm

You can use any battery where you can positively identify the + and - terminals. Most cell phone batteries have a 3rd terminal which is a thermistor to monitor the battery temperature, the 4th terminal if it has it, usually it is not used. Whatever you do, make sure you don't overcharge it and ALWAYS limit the charging current.
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Re: Li-ion power mod

Postby carlos » Mon Dec 24, 2018 7:03 pm

In this and the following post (too many images for one) I would like to share my DSO150 battery mod using two lithium cells (without a voltage regulator), one module for battery protection, one for charging and one charge level indicator module. I haven't used the device heavily since I made the mod, but so far it appears to be working nicely.

(Update: In the first reply to my posts upsss writes that the scope will behave unpredictably on low voltage with two lithium cells without a boost regulator. I'm assuming he is right about that, so be warned!)


Parts used:

- 2 lithium cells repurposed from a dead Canon LP-E5 battery which I was able to restore to sufficient capacity. The cells from this battery fit the empty space in the DSO150 amazingly well (a little too large) and give hours of battery time. ... pack-lp-e5

- battery protection module for two lithium cells "HX-2S-02 3A" ... 16563.html
(the canon battery has a protection module built in, but I had accidentally damaged that one (lifted a pad) while I was testing it the cells)

- charging module for two lithium cells based on TP5100 ... 06863.html
This module accepts input voltages in the range of 5-12V (or even up to 18V, though not recommended), so any 9V power supply used before the mod will still be adequate. (Update: I discovered that actually at least 9V (presumably at least 8.4V) of input voltage are required for this module to load two cells in series to their full capacity. Lower voltages (I tried 7.5V) are not boosted up and the charging never finishes. I assume that the 5V from the specification refer to loading a single cell, which this module can also do (configured with a solder jumper on the PCB).)

- charge level indicator panel for two lithium cells ... 95698.html
(Update 1: I had never actually tried to run the battery low until after this post. Now I'm noticing that 1) the module I received looks different than the image at Banggood (mine has the button on the sime site as the IC and has SMD LEDs) and 2) that my module is actually meant for 1 cell, not 2; so with 2 cells, it always shows the battery as "full" until the protection module kicks in. Bummer.
Update 2: Rewired the indicator to measure only one of the two cells, now it works like a charm!)

- superglue, insulation tape, double-sided tape and some random bits from my bench

I didn't take photos during the build (no camera available at the time), so here are a few disassembly shots instead:


The charge level indicator in action. It lights up only a few seconds after pressing the button, using no power at all when idle.


Here it is inactive.


As you can see, I have drilled a hole for the first green LED (which indicates full charge) to be clearly visible. I glued a small piece of thin, transparent plastic behind so that no dust can get inside. For the two green LEDs between that green one and the red one I only removed some of the material from the inside of the casing so that they are somewhat visible through the wall. The red one (which is the last one still to light when the battery charge is low) didn't need that, as apparently this plastic is more transparent to red than to green.


The button itself is made up of a shortened brass screw and a nut, carefully filed and fixed together with superglue, hanging loosely in a drilled hole in the casing. Pushing the nut makes the screwhead push the actual button on the module.


Not strictly part of the battery mod, but made in the same frenzy: A glued-on non-turn washer from a bike makes for a crude, but functional hook, so that I can put the DSO150 up on my wall.


First step of disassembly. The charge level indicator is visible on the inside of the frame, held in place by double-sided tape.


After removing the digital PCB most parts of the mod become visible: the two pouch cells hidden under black insulation tape taking up almost the entire space on the back, the charge module in front of them and the protection module squeezed in the very bottom on the very bottom.

You can see pretty much all of the circuit here, too. Note the spot where the yellow wire connects to the digital PCB of the scope: There I removed the diode D2 as a convenient way to break up the circuit. (Also with the drop of the diode the voltage of the two cells probably wouldn't be high enough to power the scope.) The black insulation tape is there to prevent contact to the charging module.

(Update: Note that I had to rewire the charge level indicator after writing this, since I discovered that it is calibrated for one cell, not two. I desoldered one lead of the light-grey/blue double wire from the middle of the PCB and resoldered it on the left where the dark grey wire connects.)


Detail from the side: A narrow piece of hard paper with a bit of foram, glued to the inside of the case at its ends, gives a bit of necessary mechanical support to the indicator board (without it and attempt to push the indicator button would just push the entire board inwards.

Note the (almost…) matching holes in the hard paper and the indicator PCB: This is done so that the LED from the TP5100 charging module can also (barely) be seen through the casing, thus giving a visual sign for if the battery is currently being charged.

As you may imagine, the charge level indicator was the most time-consuming part of the mod by far.


Here it is in action.
Last edited by carlos on Tue Dec 25, 2018 9:04 pm, edited 9 times in total.
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Re: Li-ion power mod

Postby carlos » Mon Dec 24, 2018 7:04 pm


The side rim of the digital PCB had to be trimmed a little to make enough room for the hard paper backplate of the charge indicator.


Detail of the rotary encoder PCB. To make sufficient room for the thickness of the cells, I trimmed the solder points as flat as I could and widened the top of the screw holes a bit so that the screw heads could be recessed a little deeper.


They are still leaving slight pressure marks, but apparently only on the lose top layer of insulation tape on the cells, so the cells themselves should hopefully be safe.


This is the casing of the original battery I used. It was flat-discharged, but promptly came back to life when I first charged it through the TP5100.

The idea to use two lithium cells without a voltage regulator came from this youtube video (which has potentially annoying music, be warned):

This mod doesn't use a charging circuit though, which is probably not very god for the cells. Also no charge level indicator.

The posts in this forum thread were also a great resource and inspiration for tackling this project. Thanks to all of you!
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Re: Li-ion power mod

Postby upsss » Tue Dec 25, 2018 5:17 pm

Whoever came up with this idea of using two Lithium batteries in series without a step up converter did NOT do his homework and take into account worst case condition of the batteries voltage. THIS SCOPE WILL NOT FUNCTION AT BATTERY VOLTAGE OF 6V!

Anything less than 7.5V is very unpredictable! Most Lithium battery charger/protection circuits will allow full battery operation down to about 3V per cell (that is how Lithium battery capacity is determined and circuits designed to operate) and with two of them in series you will get ONLY 6V which is in this case unacceptable!
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Re: Li-ion power mod

Postby carlos » Tue Dec 25, 2018 9:00 pm

You are right that the undervoltage protection kicks in only well under 7.5V. I wasn't aware that the scope isn't functioning reliably below that, thank you for the warning! (Thanking also for those who might otherwise follow me in making this mistake.) I will definitely watch out for wrong readings on low battery. Do you know in what way the measurements will be influenced by insufficient voltage? Is it really unpredictable?
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Re: Li-ion power mod

Postby upsss » Wed Dec 26, 2018 6:19 pm

It is unpredictable and it will vary from unit to unit. Basically at around 7.5V, which could actually be 7.5V ±0.5V the +5V and the -5V regulators will stop regulating and then anything is possible. The problem is that at that point the scope will NOT just die but will stop functioning properly and the results will be unpredictable.

You can raise a little this minimum input voltage by about 0.6V by shorting out the D2 diode next to the power input connector. Other than that, I would strongly suggest using just one Lithium battery and using a step up converter with an output of 8.0-8.5V (still short out D2, there is no need for it). You will be able to fit a larger battery and get much longer run time. Take a look at the bottom of the first page of this thread, you will see my implementation of this project. BTW, I am a EE so I know what I am talking about.
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