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pianotuna

Regina, SK, Canada

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Posted: 09/12/20 01:59pm Link  |  Quote  |  Print  |  Notify Moderator

Bert the Welder wrote:

And just for the sake of wondering.... for temps that cold, could some sort of heat pad, blanket or bag not be used to keep the lith's warm enough to function properly? (I'm picturing a Domino's pizza delivery electric warmer bag) Or, perhaps, would moving your batt's inside your camper living space. Obviously if you go with the SiO2, your good to go. But for those with Lith's already, are there options if they are occasionally stuck in temps that cold?


Hi Bert,

There are some LI that come with a built in heaters. That's fine, until the batteries run out of juice.

According to Battleborn, Li can be charged at -4 F BUT the charge rate has to be exceedingly slow. The actual charge rate was not made clear in the video. The problem is those pesky dendrites.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

Itinerant1

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Posted: 09/12/20 02:56pm Link  |  Quote  |  Print  |  Notify Moderator

This is where it gets interesting because when I ask what is the cell voltages for said 40-90% or whatever soc % is claimed for longevity I never get an answer for that voltage range, besides why not use all the battery?

I personally bought the lfp to be used in it's entire voltage range at any PSOC, its ease of recharging with solar and the light weight of the batteries, plus not having to use a generator or pedestal power at low SOC.

Mine are still young at 4.5 years and 550+/- full cycles of fulltime use and never being turned off other than one time when the bms did it's job shutting down the batteries. This is with loads from 7a-175a everyday multiple times a day. 40+ days being the longest psoc (25%-75%) before solar caught up to fully charge the batteries. I have gone through my recordings from previous years and it still shows the same voltage readings at misc PSOC. I'm sure it has used some capacity but can't detect it when comparing the voltage to SOC capacity with or without loads from 25% to 100%.

But then 14.2v (3.55vpc +/-) is the max my batteries (cells) have been charged to and float at 13.6v (3.4vpc +/-) always a load on the system.


12v 500ah (5,120Wh usable), 20 cells_ 4s5p (GBS LFMP battery system). 8 CTI 160 watt panels (1,280 watts)2s4p,Panels mounted flat. Magnum PT100 SCC, Magnum 3012 hybrid inverter, ME-ARC 50. Installed 4/2016 been on 24/7/365, daily 35-45% DOD 1,600+ cycles.

FWC

The Wilderness

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Posted: 09/14/20 07:49am Link  |  Quote  |  Print  |  Notify Moderator

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.

pianotuna

Regina, SK, Canada

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Posted: 09/14/20 08:43am Link  |  Quote  |  Print  |  Notify Moderator

FWC,

The 100 amp-hour is 450 usd.

https://azimuthsolarproducts.com/product/12v-100ah-sio2-battery/

-30=

FWC

The Wilderness

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Posted: 09/14/20 08:47am Link  |  Quote  |  Print  |  Notify Moderator

OK, and the 108Ah is $559 USD. The point about apples-to-apples costs still stands though.

01tundra

Middle, TN

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Posted: 09/14/20 09:52am Link  |  Quote  |  Print  |  Notify Moderator

Bert the Welder wrote:

And just for the sake of wondering.... for temps that cold, could some sort of heat pad, blanket or bag not be used to keep the lith's warm enough to function properly? (I'm picturing a Domino's pizza delivery electric warmer bag) Or, perhaps, would moving your batt's inside your camper living space. Obviously if you go with the SiO2, your good to go. But for those with Lith's already, are there options if they are occasionally stuck in temps that cold?



Or mount them inside the trailer instead of outside, which eliminates the low temp operation issue and increases security. Or buy one of the brands that has internal heaters or use the heating pads offered if you'd prefer to keep them outside. The entire temperature argument is a non-issue in my opinion.


2020 Rockwood Mini Lite 2109S
2017 GMC 2500HD Denali Duramax

pnichols

The Other California

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Posted: 09/14/20 12:03pm Link  |  Quote  |  Print  |  Notify Moderator

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.


Phil, 2005 E450 Itasca Spirit 24V

FWC

The Wilderness

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Joined: 09/12/2020

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Posted: 09/14/20 12:28pm Link  |  Quote  |  Print  |  Notify Moderator

pnichols wrote:


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.


The spec actually says discharged to 100% DOD (ie pull the full rated capacity out of the battery), not to zero (volts). As I pointed out this claim is not really substantially different from what deep cycle flooded battery manufacturers claim (see the graph I posted earlier with ~500 cycles to 100% DOD). I am not sure I believe either of these claims, just pointing out that the claims are about the same.

Also note that Gell Cells have a sulfuric acid electrolyte solidified with SiO2 (silica), the difference is that these appear to have more SiO2, but the concept is the same.

What spec do you think is far, far better?

pianotuna

Regina, SK, Canada

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Posted: 09/14/20 12:30pm Link  |  Quote  |  Print  |  Notify Moderator

01tundra wrote:




Or mount them inside the trailer instead of outside, which eliminates the low temp operation issue and increases security. Or buy one of the brands that has internal heaters or use the heating pads offered if you'd prefer to keep them outside. The entire temperature argument is a non-issue in my opinion.


This will do no good if the RV is in storage at -40. So extreme cold, for some of us is, a fact of life.

No one in their right mind is going to pay a premium of $109 for a gain of 8 amp-hours. I based all my looking on 100 amp-hour jars, which are a much lower initial cost than Li.

FWC

The Wilderness

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Posted: 09/14/20 01:28pm Link  |  Quote  |  Print  |  Notify Moderator

I guess I don't follow, if your RV is in storage, why would you be charging your batteries? Lithium doesn't care about sitting at partial states of charge.

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