Lithium Batteries

FWC wrote:

pianotuna wrote:

FWC wrote:
Just to be clear, I agree with you on the low temperature charging advantage of SiO2 batteries. However I would argue that there are other ways to deal with this.
Which are list at $621 and are on sale for $558. LiON energy batteries are regularly on sale at Costco for ~$730 for 112Ah. .

FWC you are referencing the Canadian dollar price for the SiO2

So make that about 440 usd.

As I've repeatedly said, Li are excellent. They simply don't meet my needs.

BTW there is at least one documented report of an LiFePo4 Pouch cell battery bank bricking itself from just one discharge to stone bone dead.

Itinerant1, I will be doing a load capacity test to stone bone dead. But I think even once may kill of an Li.

Very neat that you can monitor the temperature per cell.

Are you doing anything about cooling in the summer time?

My (limited) understanding is that, for best longevity Li prefers 40% to 90%.

I lived for a lot of years with jars that preferred 80% to 100%.

I am pretty sure I am looking at the USD page for the size that was closest to the LiONs they have for sale at Costco right now (112Ah vs 108Ah):
https://www.azimuthsolarproducts.com/product/12v-108ah-ultra-long-life-battery/

Anyway, not a big deal, but the point was that it is not a huge difference in price between the two types of batteries. If you want to get the same (claimed) life out the batteries, the lithium comes out to be significantly cheaper as the cycle life is much longer. To get a similar life out of SiO2 to LiFePO4 at 100% DOD, you can only discharge the SiO2 to ~50% DOD, so you need twice as many batteries, at more than four times the weight.

Also, if you are willing to assemble your own pack from LiFePO4 cells, then the lithium option comes out to be cheaper up front as well.

I am not sure there are examples of folks killing lithiums in any number of creative ways. But the point still stands that you can pull the entire 100% capacity out of lithiums (until the BMS shuts them down) many thousands of times, which is a major advantage over all the forms of lead acid batteries.

Again, LiFePO4 may not be the right choice for your application, and SiO2 may work better for thermal, upfront cost or other reasons. As I said before, my goal is to stress that SiO2 is not some amazing break through technology and shares most characteristics with other lead acid flavors. These are likely not the best choice for the average RVer as they don't offer the performance of lithium but still have a significant premium over other lead acid batteries.

Well ... reading this clip below from the Azimuth Solar Products Si02 webpage
https://azimuthsolarproducts.com/product/12v-108ah-ultra-long-life-battery/ under the "Additional Information" tab:

---------------------------------------------------------------------------------------------
Battery Type
SiO2 Composite Electrolyte Battery

Nominal Capacity (25°C/77°F)
108 Ah (1296 Wh) @ 20 Hour

Nominal Voltage
12V

Max Charge Current
27A

Max Charge Voltage
14.7V

Internal Resistance (25°C/77°F)
=< 6 m?

Max Discharge Current (25°C/77°F)
800A(5S)

Depth of Discharge
100% DOD

Operational Temperature
-40?C to 65?C (-40?F to 149?F)

Self Discharge
< 1.6% per Month

Life Cycle
3400 Cycles at 40% DOD; 1500 Cycles at 80% DOD; 620 Cycles at 100%
DOD

Dimensions
17.2 x 33 x 22 cm (6.77 x 13 x 8.66")

Weight
31.5 kg (69.4 lbs)

Manufacturer
Soneil International Ltd.

Warranty
2 Years Workmanship
---------------------------------------------------------------------------------------------

It sure looks to me like their SiO2 batteries function in a far, far superior way as compared to good old regular lead acid (liquid or AGM) batteries. Crystals are not the same as liquid or liquid absorbed into mats.

Note that the SiO2 batteries can even be discharged to "zero" about 620 times - which I would never think of doing even once, with any battery in my RV - no matter what the chemistry. (Excluding a capacitor battery of course!)

BTW, that maximum charge current of 27A is perfect for us folks with only 130 alternators when underway, and for us drycamping RV folks with only stock converters and very small portable generators.