LiFePo4 on Faketec

[K-Kloppstock]

Hi there,

i stared to develop a small LiFePo4 PCB in the same layout as those CN3065 from Aliexpress, i used a CN3158 charger IC and a HY2112-HB protection IC to keep the Voltage Between 3.65V for overcharge and 2.5V over discharge. Also offers the option to use a NTC for temp protection.
Goal is to have a sturdy solar node on a like a ~20AH battery to work for month without sun in remote places.

The first test with a resistive load looked good, the PCB will charge the battery and power the dummy-resistor if power is applied to either USB in or Solar in. Same way it will drain the battery if no external power is present.

If there is any interest in this project give me a ping and will will post further progress

[lorde85]

Great work! I am interested as I have plans to move my nodes to solar with lifepo4 batteries. I have some cn for lithium and was looking to change resistor to drop voltage but your build looks neat and more efficient for sure.
Where do I sign up to follow your project?

[K-Kloppstock]

PCB_PCB_CN3158+HY2112_2026-02-06.json

BOM_CN3158+HY2112_2026-02-06.csv

I hope files help, if you need to, i can turn it into a complete SMD Variant. Later this week i will post a fitting case for 3D printing. I still have some PCB to spare, if you pay for postage i will can mail you a spare one.

[lorde85]

PCB_PCB_CN3158+HY2112_2026-02-06.json

BOM_CN3158+HY2112_2026-02-06.csv

I hope files help, if you need to, i can turn it into a complete SMD Variant. Later this week i will post a fitting case for 3D printing. I still have some PCB to spare, if you pay for postage i will can mail you a spare one.

Are you planning to release the Gerber file?
I would be interested to test your design on one of my solar nodes here in Portugal. Although I don’t have most of the other parts, maybe when you have Gerber I could order all together from JLCPCB for example.

[K-Kloppstock]

Hi,

That json was exported from jlcpcb, I currently on a business trip until Sunday. I can release the Gerber files then or move that project to oshwlab this would allow direct orders at jlcpcb. Sole problem is that jlcpcb does not have the hy2112 in -HB in stock just other parts.

I tested my own design for loading from solar & usb both works also running the faketec while no external power is present works too. I just noticed that if you start the system the first time you need to supply external power for one second or so to make that CN chip work. I will also upload a housing where both this board and faketec will fit in well.

[lorde85]

Thanks for your update, great work and cool you are willing to share it.

Did you test behaviour when battery runs out and only plugged to solar? Does it wake up CN chip? ‘Cause it could happen when the faketec is out there and cloudy for days, then one would need to go up there and plug in usb to wake it up.

[K-Kloppstock]

The USB and solar take the same power path in, just one goes to a diode other through a mosfet..so either solar or USB is working fine. Before I left for business trip I plugged in a faketec on 2x18650 lifepo4 battery and let it drain until the hy2112 shuts it off. Then I will test how startup on empty battery works restart it via solar

[K-Kloppstock]

Form Still close to aliexpress cn3065 loaders, can both be slottet in

I Updated it as follow :

• Parts now 0805 instead of 1206
• All Parts SMD
• All Parts JLCPCB Stock
• THT Holes still remain
• Switched back to micro USB instead of C ( needs additional resistor to work with every cable )

I had my node finally run for 1+ week plus, tried reboot works on either Solar or USB

If you need no further modification i will make it availible for public

[lorde85]

Looks great! Publish it and I’ll have it a go. 👏🏼🙌

[iuvi7]

Sweet job!

What about small FAQ? Or Guide to build?

It seems i need few LiFePo4 but not in parallel but in line? Where what to connect? How to add resistor for type-c?

P.s. plate is cool, is it possible to make 4 holes somewhere for nuts \ screws to hold?

Thankssss

[K-Kloppstock]

Hi iuvi7

i added those infos on the bottom silk layer,

Later when i am home i can check if there is space for holes , in 3.2 mm

Sadly the CN3158 is a single cell ( single series ) LifePo4 charger for small solar projects. As of now i do not plan anything in this direction.

BR

[lorde85]

Form Still close to aliexpress cn3065 loaders, can both be slottet in

I Updated it as follow :

• Parts now 0805 instead of 1206
• All Parts SMD
• All Parts JLCPCB Stock
• THT Holes still remain
• Switched back to micro USB instead of C ( needs additional resistor to work with every cable )

I had my node finally run for 1+ week plus, tried reboot works on either Solar or USB

If you need no further modification i will make it availible for public

I was adding the parts in JLCPCB but item is no longer available:
- MFR.Part # PH-2PSurface Mount，Right Angle // JLCPCB Part #: C47647
Replacement suggested by JLCPCB is:
- JLCPCB Part #: C968533

Ready to add to cart, just let us know when you publish the gerber ;)

[K-Kloppstock]

Gerber_CN3158+HY2112_PCB_SMD-1206-THT.zip
Gerber_CN3158+HY2112-SMD-0805_PCB.zip

Here you go, both have the same Layout

the SMD1206 is the design i use at home, has THT PH2 terminal and eye friendly 1206 SMD

other is for complete SMD assembly by JLCPCB with 0805 SMD

function is 1:1 the same

@ iuvi7 sadly i see no good place for holes, but i can design you a printable support to mount it via holes if you need.

BR

Update :

https://de.aliexpress.com/item/1005006370326779.html

this is the NTC you can use, i just used a jumper with a 2,54 mm pitch header
since the CN3158 supports a NTC i felt bad for leaving the option out

[iuvi7]

@K-Kloppstock Thanks, i could do 3D design and part , but thanks!

So it just one LifePo4 wich gives 3.2 volts, then you use some power transformator to like 5V, so nrf can works on 3.3V logic, correct?

[K-Kloppstock]

Hi,

no i just apply 3.2 directly to my faketec node, works pretty fine. I choose to to so after some options

1. use this and have 5V : https://oshwlab.com/wagiminator/y-cn3801-lifepo4-solar-charger_copy_copy but takes away some % for chargeing, so i loose runtime
   For reference non Solar charger :
   https://oshwlab.com/wagiminator/cn3058-lifepo4-power-board-ls-5v
   https://oshwlab.com/wagiminator/cn3058-lifepo4-power-board-ls-3v3

2. use this : https://de.aliexpress.com/item/1005008094801881.html , still cutdown of efficacy due to step up converter, no deep chargce protection, so you need to add https://de.aliexpress.com/item/1005001732120817.html

this was all not satisfying to me therefore i started to look up all kind of specs
https://github.com/joric/nrfmicro/wiki/ALternatives
https://docs.nordicsemi.com/bundle/ps_nrf52840/page/keyfeatures_html5.html

so the battery goes directly into the nrf52840 wich supports input of 1,7 to 5,5 v if you look at the power input you can clearly see that either battery voltage or usb voltage goes in and a LiFePo4 is perfectly in this range

also i especially used the hy2112-hb variant to keep the voltage in a somewhat good working window

i know that around ~ 2,6 v a brownout can happen but i will take this gamble.

Sole reason for using LiFePo4 is less danger from battery, bit more stable against cold, also i get a 20ah C40 LiFePo4 for around 9€

Using it to ~ 2,7 V will give me around 1800 hours in energy saving mode, so it should survive ~1 month without sun in winter easyly.

I will keep you updated about Node design an long term experience

[iuvi7]

@K-Kloppstock

Awesome! Thanks a lot 🙏🙏🙏

One more question if you could pls 🙏

Had you ever heard or have idea how \ if it possible to make realisation of power&control FakeTec node over Etehernet PoE (LAN cable) ?

I use to put it on hight mast (20-30m from ground) but BT connection with external antenna quite tuff

Thanks