Burgduino an Arduino UPS/Lithium Battery Charger & more

[soubitos]

This is the "final" design for the prototype pcbs..
This is a 1S lithium battery charger / UPS and a lot more depending on software and how each user wants to scale up.
There are three "shields" Each can be used separately and all three together!
First shield is the charger. It can charge 1S battery with max 1A, has a boost converter onboard (0.6-12V/max1A outp) and will supply power to a load while charging the battery so the charge cycle is not interrupted by the load unless it consumes a lot more than the availabel power of the input - the power needed by the charger. The charger can be used as standalone device without any problems or can be hooked up to an arduino and allow it to measure Output and battery voltages and charge current. It will also allow arduino to change max charge current setting, enable or disable the boost converter and even enable or disable the charger itself.
The second shield is a logic board, similar to the 1602+keypad already in the market but with the addition of an atmega8 & RTC clock and also a i2c chip for the lcd to free up pins on the atmega8. This will be able to control the charger as with an arduino but also allow for example to enable disable the boost converter on a set time in the future. It is also possible to attach an arduino too, sharing some of the functions like ie the keypad.
And the last shield is a battery compartment. It hooks to the added header for battery on the charger. It has room for up to two 18650 cells on a holder or tabbed versions can also be used (saving a little cost too and lowering its profile by a couple mm).
I'd like to hear your opinions about this project!
I'd also like to know what a fair price for such a device would be for you and if anyone would be interested to develop software/applications for it

Image are the charger board top and bottom, the "logic" board top and bottom and finally the battery "shield" top and bottom (ok not much to it)

[soubitos]

Redesigned the battery shield.
Up to 4 can now be stacked forming packs of 1S1-2P and up to 4S2P configured with solder jumpers. Also the 4 NTC onboard can be configured depending on how many shields are stacked.
I consider adding room for an optional or user installed I2C temp sensor and a connector for lipo cells but i have not made my mind yet!

[soubitos]

And final version of the 1S1-2P /1A charger shield (to begin with).
Also added 3.3V rail to the logic shield so it can relate with RPi easier

I dont see any comments but if anybody is interested on the project and would like to chip in to have the first prototypes made, he is most welcome to let me know!!!!

[soubitos]

I'd really appreciate any comments! how does the layout and routing look like to you? the project in whole?

[metrologist]

I don't really know anything else about the project other than the board images and brief descriptions here.

What was the main objective of the project or original problem statement?

I am looking for an application ATM.

I can see it may provide identical functionality as an inexpensive battery bank, but this one has some provision for the user to integrate a programmable output. I suspect the shield provides no functionality as built, however, and the user needs to provide an Uno type controller and figure out the interface and programming.

LCD shield?

4S2P is 8 cells?

[soubitos]

This is not a powerbank.. its function allows the battery to be charging while the load is powered from the main power source so the charging cycle is not affected. It operates exactly as a UPS. Your application is powered by your main power source while the batteries are kept charged.. When power fails Burgduino takes over and your application is working as usual while the battery level is monitored. At a low level point it can disable the external load for example or switch to another power source or send message online if connected.. there are a lot of possibilities in that field. 
Each of the three shields can be used without the others.. the battery shield obviously can house batteries but the charger can operate "manually" while it can be turned to "automated" either by use of existing arduino or RPi (perhaps others) inter-grading in existing application or simply on a bench/lab, while adding the logic shield (which hosts an RTC/ATMEGA8/I2C controller for the LCD it can be automated, user can interact with it changing charging current, monitoring charge cycle, output voltage etc.
The logic shield has provisions to be either 3.3 or 5v powered for easier communication with 3.3v logic while another arduino can be attached and take over some or full control of the "pack".
The charger is one out of more to come if this one proves its worth with a 2-3&4S versions to come.
As for battery configuration 1 shield can be configured either as 1S2P or 2S1P, 2Shields can form a 1S4P/2S2P/4S1P pack while when two shields are connected the NTC "bridge" is shared between them. Similarly when 3 or 4 shields are attached. In that case with a 3rd shield a 3S1P/3S2P can be formed (unfortunately for 3S 3 shields are needed) and of course 1S6P, 2S3P. Finally with a 4th shield a 4S2P pack is possible. I dont see further expansion in this format as viable although it would be possible.. The charger has provision for external cells anyway so it can work without the battery shield anyway.
Via software the on-board atmega or other micro-controller has access to the charger board to take measurements and act accordingly, it can enable disable both the output booster or charger ic and with the RTC on the logic board this can be time programmed as well... Truth is, i will not be the one programming this, I am not a software guy but i can only say i believe this to have a lot of possibilities ahead as it can meet demand for ups/power source for external loads other than 3/3/5v and it is .. fun! (it is even funnier that this will not kill the bank!)

[metrologist]

The charger can be used as standalone device without any problems or can be hooked up to an arduino and allow it to measure Output and battery voltages and charge current. It will also allow arduino to change max charge current setting, enable or disable the boost converter and even enable or disable the charger itself.

Did you post schematics for the charger/ups? I was wondering how the Arduino hardware can monitor/control these aspects. It sounds like software could also make this device a solar charge controller as well.

[soubitos]

The charger can be used as standalone device without any problems or can be hooked up to an arduino and allow it to measure Output and battery voltages and charge current. It will also allow arduino to change max charge current setting, enable or disable the boost converter and even enable or disable the charger itself.

Did you post schematics for the charger/ups? I was wondering how the Arduino hardware can monitor/control these aspects. It sounds like software could also make this device a solar charge controller as well.

No I have not posted schematics..
I will at a later time when at least i have more charger/booster varieties ready but yes, a solar charger is well into planning... actually, as it is it accepts 8-45V input and in its "brother" form of TP4056FlexAdv (https://www.eevblog.com/forum/reviews/tp4056flexadv-review/) works very well with solar panels .. controlling it is a whole other issue though so i will wait for another charger shield most possibly based on a more "capable" IC than TP4056 used in these chargers!

[soubitos]

All parts and pcbs have been ordered for the first 10 prototypes!
It helped a great deal TP4056FlexAdv sold several pieces over the past few days as sales of this charger are financing all other projects

[soubitos]

While i dont see anybody commenting on this one, i am designing and have almost ready a 2S2A and a 3S2A charger shields and i am also working on a solar charger shield with mppt for Lead Acid and a similar one for Lithium cells.
I would love to hear what others think about this project and especially those interested to get their hands on an early prototype and help with its software!

[soubitos]

Early prototype of the Logic Shield for the Burgduino modular charging system

[soubitos]

Early prototype of the battery shield for Burgduino modular charging system

[soubitos]

Just a little update on this ongoing project.
I am working on various spinoff charger solutions, from dead simple like this one to more elaborate.
This is a near finished prototype, some bodge wiring required to communicate with the arduino it will be supporting but can work as standalone as you see here. It looks great with the burgduino battery shield but i am having problem finding long enough stackable headers, any ideas for (prefferably cheap) sources?
It also works very well with the burgduino logic shield but that is a whole other story as i am reworking that aspect of the project all together with an atmega328 instead of atmega8, rotary encoder instead of keypad and oled instead of 1602 lcd.
The actual charger displayed here has 5V micro USB or 5-45V DC jack input, charges cells with 50-100-250-500-750 or 1000mA selected from the dip switch, of course has protection for the cells including NTC (optional, can be disabled) and the batteries are actually connected to the screw terminal so the interconnection is part of what i am working on improving really.. i think brass standoffs!
Then there are two boost converters, one fixed 5V1A to supply power to the arduino and a second adjustable from battery level 3-4.2V up to 12V/1Amax. The adjustable boost converted can be disabled or enabled by onboard switch but can also be controlled by the arduino (D7). It also drives battery voltage, charge current and adjustable boost converter output measurements to the arduino (A1-A2-A3),
Last but not least, this is the type of charger/ups which will happily charge the battery while supplying current to the arduino/external load (1A max combined) via power path implementation. It is also possible to connect any load to directly to the battery for example an external boost converter, in which case depending on battery quality/condition it can draw up to 2.5A but if charging at the moment, the batteries will support the output while discharging ....
If by chance anybody wants one of these prototypes to play with, i can sell 4-5pcs for 10$ each, also if someone wants to review the prototypes or use them in a project that will be made public, let me know... last, but not least this version uses TP/TC4056 as main charger IC, in future versions i plan to use a different charger and protection IC set allowing the same design and pcb to support either Li Ion / LiPo or LiFePO4 batteries...