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obitus1990
New Orleans, LA, USA

Posted Tue Mar 02, 2021 6:34 pm

I wasn't concerned about it leaking. I was asking primarily since the main challenge in charging a Li-Ion battery is to realize the battery's full capacity without overcharging it, which could result in catastrophic failure. There is little room for error, only ±1%. Overcharging by more than +1% could result in battery failure, but undercharging by more than 1% results in reduced capacity. As I understand it, special attention has to be paid to charging circuit design when dealing with Li-ion batteries.

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Stumpi
Germany
Website

Posted Wed Mar 03, 2021 2:21 am

Ah, I see. I followed the corresponding data sheets 100% when designing the hardware. The charging circuit used on the board is taken 1:1 from the data sheet of the MS920SE. To guarantee a correct charge a 3.3v regulator was used to stabilize the voltage of the charge. It is impossible to "overcharge" a 3.3v cell with 3.3v charge voltage ;) The opposite is the case, the cell will never be 100% full, max. 99.9%, but hey that's the "simple" in SimpleClock ;-).
It is important when rebuilding that you keep to the specifications of the values of the components used. The current limitation is realized by the 620Ohm resistor.
MS920SE_Charge.jpg

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BatteMan
France
Website

Posted Mon Mar 15, 2021 12:54 pm

I just received my 5 PCB from JLCPCB. They're very sexy ;)

I also bought some batteries on AliExpress and made a command to DigiKey but they don't have "587-5436-1-ND" in stock for now (and Mouser asks 20 EUR to send this article to France :shock: ). So this item is in my DigiKey command, hope to receive all parts asap.

I bought to build two SimpleClock, so if I'm good enough, I'll have one to sell ^^ (and 3 PCB too).

More to come :-D

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Zippy Zapp
CA, USA

Posted Mon Mar 15, 2021 3:48 pm

Shipping gets you sometimes.

Try this one :
587-1436-1-ND

Should be the same cap just a different packaging in this case -T instead of -P.

User avatar
BatteMan
France
Website

Posted Mon Mar 15, 2021 4:03 pm

Thx, I'll have a look to it tomorrow ;)

[EDIT 1] All in stock (with the replacement item ^^).
Just need to wait now, and look if my equipment is good enough to solder all this stuff ! :D

[NEW EDIT] In my command (and in the BOM), I see support/pin for the cpu (the "ED3764-ND" item) but I don't see connector/pin for the motherboard (if I can say this).
Yes, I know... I dont' know where I'm going :lol:

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Stumpi
Germany
Website

Posted Thu Mar 18, 2021 2:47 pm

You need something like this:
2 * 40 Pin Singles Row Straight Round Pin Header
https://www.ebay.de/itm/10Pcs-Gold-Plat ... 2771310268

It seems i forgot it in the BOM :(

User avatar
Stumpi
Germany
Website

Posted Fri Mar 19, 2021 12:59 am

Digikey BOM updated. Added
"920-0172-01","1988-1163-ND","2"

but you'll get it very cheaper at ebay ;)

User avatar
BatteMan
France
Website

Posted Fri Mar 19, 2021 2:51 am

Thx !

I'll try to get all stuff for my next holidays ;)

[EDIT] Just bought 6 on eBay, from France ^^
Now, I must buy a "third hand", flux and some cool stuff for soldering it correctly (I only soldered little pieces and a Kitco, so it'll be a world premiere for me ^^)

User avatar
BatteMan
France
Website

Posted Wed Mar 24, 2021 8:30 am

UPS informed me that I need to pay 80 EUR for customs and others fees (with 11,80 EUR of VAT, 11 EUR of gouvernemental charges and... 59 EUR of brokerage charges...).

I initialy payed 31 EUR + 18 EUR of shipping costs...

And the best is coming, if I decide to refuse the package, Digikey will not refund me and will charge me for shipping costs and extra fees !

So, my choices are : pay 130 EUR... or lose 50 EUR and pay at least 20 or 30 EUR more...

My SimpleClock will cost me an arm :lol: (and I haven't bought tin and others yet :roll: ).

User avatar
JoeUser
Dallas, TX

Posted Wed Mar 24, 2021 8:46 am

Oh, man! That certainly sucks, for sure!

Highway robbery is alive and well in the shipping industry, for sure...





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