The 123 battery manufacturer went bankrupt. A Chinese company wanted to buy it but Obama said no.

I use Li-Po batteries for my electric radio-controlled model airplanes. They DO NOT have a protection circuit since it is in the charger and airplane.
Some Li-Po model batteries can provide over 200A! That will cause a pretty big fire if something shorts. Lithium burns with an extremely hot flame like magnesium (flares) and titanium.
Water on a 'ium fire makes it burn hotter.

 

The 123 battery manufacturer went bankrupt. A Chinese company wanted to buy it but Obama said no.

I use Li-Po batteries for my electric radio-controlled model airplanes. They DO NOT have a protection circuit since it is in the charger and airplane.
Some Li-Po model batteries can provide over 200A! That will cause a pretty big fire if something shorts. Lithium burns with an extremely hot flame like magnesium (flares) and titanium.
Water on a 'ium fire makes it burn hotter.

What does Obama have to do with an ordinary battery cell format? This is not clear to me.

If you break up old button cells and add a drop of water they will fizzle a bit but that's that.

Even good NiMH cells will easily burn wires.

With these AAA cells so cheap here a big 12 pcs or 16 pcs blister just 2 Euro, they are an option in favour of Li-ion.

But AAA holders are a pain to insert or to remove cells. And AA cells are too long eat too much space.

 

that sounds usefull what is the part number?

DS3231 is an I²C version, I'm not sure if that is the one ErnieM is referring to or not, but has the same function.

The DS3231 is a low-cost, extremely accurate I²C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, and maintains accurate timekeeping when main power to the device is interrupted. The integration of the crystal resonator enhances the long-term accuracy of the device as well as reduces the piece-part count in a manufacturing line.

 

DS3231 is an I²C version, I'm not sure if that is the one ErnieM is referring to or not, but has the same function.

thanks, ok i would use that but i need a 1 wire rtc the ds 2417

thanks anyway

 

Last few times I needed a RTC I used a discrete ic device that not only has the crystal built in but also monitors it's own temperature to remove changes from delta T.

Let me know if you want the part numbers I can get them later.

that sounds usefull what is the part number?

I first found the Maxim part number DS3231S#, which comes in a 16 pin SOIC. Single piece from DigiKey is $8.38 USD.

Later on I discovered (from a post on this forum BTW) the PCF2129AT from NXP, 20 pin SOIC. Single piece from DigiKey is $3.23 USD.

Guess which one I use going forward?

I am not aware of any similar 1-wire units (and I checked my usual suspects).

 

What does Obama have to do with an ordinary battery cell format? This is not clear to me.

The batteries produced by A123 systems were a weird form of lower voltage lithium rechargeable. 6 months ago they got 249 million dollars as a grant from the US government. Then LG batteries from Korea were selected for the Chevy Volt instead and another car company also rejected them.
When they went bankrupt a Chinese company wanted to buy them but Obama said no, they cannot buy them. Obama said that A123 Systems must stay American or be gone. So it is gone.