Ready for the next generation of batteries?

[papaof2]

Sodium ion 220AH, 2.1 volt cells. These are from a battery manufacturer so they're looking for big orders but will accept smaller orders because someone developing battery-powered equipment / vehicles might initially only need enough cells for testing a prototype.

4 to 99 pieces $87.00 each plus shipping

Need to determine shipping costs but these are being hyped as "better than any lithium battery" - remember that the saltwater battery of a few years ago was to be "the be-all and end-all of all batteries".

However, they list a lead time of 2 days for up to 64 pieces so they are in production now.

www.alibaba.com/product-detail/Exliporc-New-strong-Battery-strong-220Ah_1600989334373.html?spm=a2700.pcdrm.0.0.14faRowrRowrLn&s=p

At 2.1 volts, you'd need 6 cells in series for a 12 volt, 220AH battery or 24 cells in series-parallel for a 12 volt 880AH battery bank. That's the minimum capacity I'm looking for, which would provide close to 48 hours of fridge, furnace and a little lighting without any solar or generator power needed in winter. The freezer is OK for 24 hours without power so just power it alternate hours using a timer and it should be fine for at least 48 hours).

Each cell is 4.5kg (9.92lb) so a 12 volt, 220AH battery using 6 of these cells would be 59.5lb or less than the weight of a 100AH 12 volt AGM battery and with a life cycle of 4000 cycles to probably 80% discharge - at best, AGM is 1200 cycles to 50% discharge (where the battery is at 80% of original capacity).

24 * $87 = $2088 + shipping so a little more than 16 first grade LiFepo4 280AH cells to make four 12 volt, 280AH battery packs. I don't yet have a source of BMS units for sodium ion batteries so that's still an unknown.

Anyone have an extra $3000 or so they'd like to contribute to research? ;-)

There are some smaller cells 40140 (40mm diameter, 140mm long) 15AH (in header, 10AH farther down in the page) for $7.72/cell in quantities of 4 to 99 plus shipping ("To be negotiated" on their page).

www.alibaba.com/product-detail/Exliporc-40140-High-Rate-Sodium-strong_1600960435468.html?spm=a2700.pcdrm.0.0.7231B1tJB1tJ58&s=p

[feralferret]

Certainly something to keep an eye on.

[techsar]

Great that they think battery tech is evolving....but I don't see how a more expensive battery with a shorter lifespan is "better."

[papaof2]

The newer batteries have much longer lifetimes than the lead-acid grandparents. The AGM batteries in my backup system are rated for about 1200 cycles to 50% discharge (commercial "life" is when they drop to 80% of original capacity). Basic AGM batteries have a 3-5 of 5-7 year life depending on the maker. Higher-end AGMs (names escape me at the moment) may have 10+ year life. Some of the Surrette batteries have 15+ year life.

Lithium ion can have 5000 cycle life if you charge to 75% and discharge to 25% - the US military designs things with lithium ion batteries for charge to 80%, discharge to 20%.

LiFePO4 cells are typically 4000 cycles to 80% discharge but I have some that are rated 12,000 cycles to 80% discharge. 4000 cycles at 1 cycle/day is 10.95 years - better than most of the common lead-acid batteries. 12,000 cycles at 1 cycle/day is 32.87 years. That's approaching the life of submarine lead-acid batteries. Lithium Titanate Oxide (LTO) batteries are rated for 20,000 charge/discharge cycles. They use small LTO batteries for the battery for the restart every time the vehicle stops BMW's.

[techsar]

 s but these are being hyped as "better than any lithium battery" - 

...is what my post was directed towards. So even though they may be better than AGM (or VRLA) they do not exceed "any lithium battery."

My LiFePO4 are warranted for 10,000 cycles or over 27 years @ one cycle/day...and they often do not cycle that frequently.

ETA: Even the replies on the page have links to various lithium-type batteries for less $ with more cycles.

[papaof2]

Whatever the latest battery technology is will probably reach "fad" levels until the real-world results come in.

I nursed a set of used, end-of-life "data center grade" AGM batteries almost to age 9 but I try be very aware of the discharge levels I subject the backup batteries to which does extend their life - regardless of the chemistry.
Based on real-world usage reports, I plan to have LiFePO4 as the replacements when the current set of AGMs reaches end of life - possibly within two years based on their age and amount of power they can now deliver.

With the batteries in backup service that doesn't see one cycle per week and me being 70+, LiFePO4 batteries will likely be "lifetime" batteries in my application. If we don't have an outage, I plan to exercise them once every three weeks or so with a 10% discharge (as I do the AGMs) to verify that all connections are tight and that nothing warms up at that level which should ensure that nothing would overheat at the planned loads.