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Sodium Batteries

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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
Topic starter  

I have 20 18650 size Na (Sodium Ion) batteries on the way. The delivered cost is $41 USD.

There are NO chargers on the market yet, but I have a SkyRC MC3000 programmable charger and have discovered that the Lithium program can be modified for charging, and the LTO program for discharging (capacity measurement, cycle, storage) Both Lithium and Sodium require CC-CV with TC (termination current) charge profiles so it is simply a matter of changing the Charged voltage from 3.7 to 3.95, 4.0, 4.1 depending on what NA you get. LTO is the only profile that allows the fully discharged voltage to go down to 1.5V.

I will let everyone know how they do.

These are 1500mAh so MUCH less power than Li but 100% safe and cheap. NOT good for airplanes, but boats and cars ok. Not a good Tesla replacement, even less range. Great for whole house like the Tesla Powerwall.

BTW, charge time can be as low as 5 to 15 mins! That means at 15mins, at least 16 and as much as 24 charge cycles per day so a 2kW solar array can fully charge 32kWh to 48kWh of battery bank.

They are also much better in the cold so full time RVers could use them.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
Topic starter  

I have not yet received the Na batteries, but I did just get a second batch of Li-Ion. These are labelled as 3500mAh, and they test at 3150mAh on average. The Li are at least 2X capacity. Prices are in Canadian $ delivered. Li-Ion 18650 3500mAh, 10 for $55, Na is 20 for $42. Since we need a bit more than 2 Na to equal a Li-Ion, the prices are very close per cell, $5.50 Li-Ion, and $5.08 Na. Or $21 Na vs $22.70 Na assuming 1300mAh vs 3150mAh.

Bottom line, cost is equivalent.

BTW, The Li-Ion has been measured and tested on a SkyRC MC3000 so capacity is correct.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
Topic starter  

The batteries are here. They arrived at 2.5V which is what I had determined to be the storage voltage. I am now doing a discharge to 1.5V at 750 mA. Then I will charge to 4.1 at 750 mA to determine capacity (s/b 1500 mAh) then I will discharge again but to the storage voltage of 2.5V. More later.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 4 years ago
Posts: 7334
Topic starter  

I am saddened to report that using the closest charging algorithm and modifying it has failed biug time. I set the current to 750 mA which is the recommended 0.5C but the charger only saw 150 mA so at 4 hrs in starting at 1.5V i was only at 2.98 V and about 600 mAh or less than half way. The battery maker knew of NO chargers yet. Rumours are there may be one in the works.

My SkyRC MC3000 is very programmable, but clearly something is wrong.

At the moment, these 20 batteries are paperweights but if/when anything changes vis-a-vis chargers I will update this.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.


   
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