LiPo LIR2032 Rechargeable for Puck modification

Sun 2020.03.22

Puck landing page indicates: 'based on a normal CR2032 battery'

http://www.espruino.com/Puck.js

A standard (normal) Lithium Manganese Dioxide (LiMn02) is 3V nominal with a capaity of 210-230 mAh

https://www.batteryequivalents.com/lithium-cr2032-dl2032-br2032-ml2032-lir2032-lr2032-batteries-equivalents-and-replacements.html

Although much lower capacity, LiR2032 battery is 3.6 V battery, with typical capacity in 50-70 mAh range and may be charged 500+ times. (lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium nickel cobalt aluminum oxide - range 3V2 - 3V9)

Note on schematic indicates Diode at D7
see lower left
https://github.com/espruino/EspruinoBoard/blob/master/Puck.js/pdf/puckjs_sch.pdf

with note 'allow LiPo 2032s to be used if diode in here'

Instruction indicate to cut trace: 'If you cut the trace and solder a diode in, that'll drop the voltage enough that you can use a LiPo.'

http://forum.espruino.com/comments/13161325/

I've stared at layout and Puck itself and have located D7

https://github.com/espruino/EspruinoBoard/blob/master/Puck.js/pdf/puckjs_brd.pdf

but it isn't clear where the trace to cut is. It looks like the diode should be soldered between D7 - D8, but unsure of that also, but no trace between the two. (could it be on the back side of the board? - not easily accessible)

A diagram would really help here and maybe a photo if someone has made the mod.

I haven't made this mod myself (yet), but was considering it & also read the threads you link to above. I opened the board schematic/layout in Eagle & I think I've figured it out.

The confusion is from the fact that there are two different things called D7 - the diode part name in the Eagle file is "D7", whereas the pad you're looking at is the GPIO pin called "D7", but they are actually unrelated.

It appears to me that Diode D7 is meant to be soldered to the two pads on the left side of the board, near the D27 pin - see the attached photo. In Eagle, these two pads are connected, so "cut the trace" presumably means the trace directly underneath the area between these two pads (being extremely careful not to cut the nearby traces to D28-31).

Hopefully Gordon can chime in and correct me if I'm wrong :)

Edit to add: re: orientation, the part symbol in Eagle shows the cathode (-) pointing down (towards the row of D28-31 pins)

2 Attachments

I agree with you @dandelany as that big blob, 10 O'Clock to your red outline appears to be the battery holder tab. Didn't even occur to me that D7 without a plated through hole was in fact a GPIO pin solder pad. Good Catch!!

Also considering a simple hack of a 18650 backpack with a CR2032 slide in tab, based on this great idea that had limited production back in X-Mas 2017 and no longer manufactured:

https://www.razimports.com/Shop/Details.aspx?Prodid=3416184

That product resulted during a powering discussion that @oesterle presented an image in this forum post: Owen Project in which he created a AAx2 using a slide in tab.

@dandelany spot on - yes, that's exactly where you need to cut and put the diode.

Just a note that the Puck.js v2 won't have the space for a diode - it never really seemed like it got used.

However if you want to use a CR2032 adaptor, 2x AAs, or a LiFePo4 battery would be perfect

Mon 2020.03.23

Puck.js V3 will have ;-)

'Puck.js v2 won't have the space for a diode - it never really seemed like it got used'

Surprises me as it was extremely intuitive Puck.js V1 to have such a small space reserved for what might be a user demand requirement. I've noticed a larger need (recycleable) for rechargeables as LiIon etal takes off.    medium disappointment oversight not to have continued that feature IMO

Did you means something like this:

https://www.stlfinder.com/3dmodels/cr2032-to-cr2430-adapter/

or was 'adaptor' meant to just mean a different solution?

re: 'CR2032 adaptor'

Anyone have a link?

'CR2032 adaptor' Anyone have a link?

I meant what you posted in the very last post: https://www.razimports.com/Shop/Details.aspx?Prodid=3416184

Unfortunately it looks like the adapter from that link is out of stock and may no longer be available... However, I did see this (even better IMO) one on Tindie:

https://www.tindie.com/products/bobricius/coin-cell-battery-emulator-cr2016cr2032/

Powered by microUSB w/ 3V regulator & it even has handy contacts to hook up an ammeter. The same seller has a number of other cool gadgets in their Tindie store...

Wed 2020.03.25

post #6 'I meant what you posted'
post #7 ' it looks like the adapter from that link is out of stock and may no longer be available'

It seems my comment 'and no longer manufactured' in post #3 is misunderstood. I contacted razimports post X-Mas 2017 and they indicated it was a limited production run to test saleability over that Holiday. No plans to re-manufacture from lack luster sales. Inventory ran out some time 2018.

From post #7 cool idea and nice features but Geez! for that price plus S&H, I'll continue with my protoboard samich (sic) that will even include the needed voltage drop diode between the layers. Should only cost time as I have scrap circuit board lying around.

Just to add, bobricius is a really nice guy:

https://www.tindie.com/products/bobriciu­s/coin-cell-battery-emulator-cr2016cr203­2/

It might not be super cheap, but it's nice to support him :)