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pianotuna

Regina, SK, Canada

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Posted: 09/12/20 11:10am Link  |  Quote  |  Print  |  Notify Moderator

FWC wrote:

There seems to be a lot of confusion about these, possibly arising from the fact that no one is actually using them. A couple of things that may help - these are lead acid batteries, and have the same electrochemistry as all the other flavors of lead acid battery (AGM, flooded, gel etc). The only parameter that they differ significantly from other lead acid batteries is low temperature charging, as there electrolyte is already crystalline, and therefore they won't freeze like a liquid electrolyte at a deep discharge. They are not comparable to the various lithium chemistries (which are a completely different electrochemistry), which have significant advantages in terms of energy density (by weight and volume) rate of charge, cycle life, self discharge, partial charge etc.

This is also not new technology. There was another wave of companies pushing this 'break through' technology a decade ago. But you will notice, with the exception of some niche applications such as low temperature telecom installations, it has not taken off and it has not been adopted by any of the major battery manufacturers. There is a reason for this - unless you desperately need high rate and deep DOD low temperature charging, there is no significant advantage over regular lead acid, which is well known and available from established manufacturers.

You will also notice that almost all the performance information on SiO2/lead crystal batteries is in the form of marketing from people selling them. There is almost no independent testing or scholarly research on them, which is a major red flag.

I don't have a dog in this fight beyond having looked into these batteries some time ago for some remote instrumentation we were installing in Antarctica. What worries me is that these seem to be being promoted as some amazing new thing for RVers, and somehow equivalent in performance to LiFePO4, when they really aren't. If you really do need to charge at -40C, then maybe they are worth looking into, but for general use, stick with well known deep cycle/AGM manufacturers or LiFePO4.

PS if you do need to charge at -40C, you are going to have other problems than the just the battery - check the specs on your power electronics, I doubt many will work well at those temperatures.


SiO2 don't sulphate and don't require 100% recharging each and very cycle.

Let me know how well LI work if you discharge them to stone bone dead say 25 times? SiO2 allows that 620 times.

Let me know how to charge an LiFeP04 at -40, in any reasonable time frame.

My electronics do just fine at -37 C.

And yes, my RV is modified to endure such temperatures, with auxiliary heaters where they are needed, and electric heated carpets.

SiO2 behave much more like LI than any flooded or agm jar.

There are few folks using SiO2, but I'll be going that route in summer of 2021 and will of course test and post results.


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.

pianotuna

Regina, SK, Canada

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Posted: 09/12/20 11:11am Link  |  Quote  |  Print  |  Notify Moderator

BTW I think LI are great--so long is you are not in cold weather. I don't like the initial high price.

Itinerant1

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Posted: 09/12/20 11:25am Link  |  Quote  |  Print  |  Notify Moderator

If a person discharges a lfp 100% without proper protection they might deserve to have an expensive brick and doing it 25 times is just idiotic.

Pianotuna are you going to test the 25 times bone dead depletion with no harm to the batteries, I won't hold you to the 620 times. [emoticon]


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: 09/12/20 11:42am Link  |  Quote  |  Print  |  Notify Moderator

If we want to compare spec sheets, LiFePO4 claim to be able to cycle to 100% DOD (aka stone bone dead) ~2000 times:
[image]

Standard deep cycle lead acid batteries also claim to be able discharge to 100% DOD ~500 times, so I don't really see a difference here, particularly given that none of this is backed up with actual data:

[image]

Contrary to the marketing materials SiO2 batteries absolutely do sulphate. Like other gel cells, they are less sensitive to this reaction path, but the fundamental electrochemistry is still the same sulfuric acid/lead/lead oxide reaction.

This brings up the point that'SiO2' batteries behave almost exactly the same as Gel Cell lead acid batteries, as that is essentially what they are. Gel cells are based on a sulfuric acid electrolyte, thickened with silica powder (aka SiO2):
https://en.wikipedia.org/wiki/VRLA_battery#Gel_battery

'SiO2' just has a higher silica content than traditional gel cells. There is no magic here.

FWC

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Posted: 09/12/20 11:57am Link  |  Quote  |  Print  |  Notify Moderator

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.

One other thing I am not following is a major price advantage of SiO2 batteries. I think the ones that were referenced were these:
https://www.azimuthsolarproducts.com/product/12v-108ah-ultra-long-life-battery/
Which are list at $621 and are on sale for $558. LiON energy batteries are regularly on sale at Costco for ~$730 for 112Ah. So yes the SiO2 have a slightly lower up front cost, but based on their spec'd lifetime the LiON total cost of ownership is much lower.

Bert the Welder

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

pianotuna wrote:

Hi Bert the Welder,

I have AGM's because I got rather tired of laying down in the snow to check electrolyte levels in seven Group 29 12 volt jars, totaling 875 amp-hours.

There is only one Li formulation that can work at -40. It is still, as far as I am aware, not available in a 100 amp hour battery.

The other issue is HEAVY inverter use. AGM's are a bit better than Li at that. I often draw 190 amps from the battery bank.

My particular AGM's are telcom batteries that are 4 years old and were "reconditioned" pulls from Cell phone towers. They were purchased because of price. New, they would cost about the same as SiO2.

My next bank, unless I can find something better, will be SiO2 and that will probably happen in July or August 2021. I'm debating whether to get 600 amp-hours, or 400.

I have a lot of respect for Itinerant 1. He has done his research carefully.

I wanted my RV to behave as if it were plugged into shore power, without generator use. I mostly succeeded and for the first five years I did not own a generator.

I wish I had not caved in and gotten a generator. It has, since I started, cost me over $12000.00. Considering that I use the generator less than 100 hours per year, it is a pretty pricey item. For that, I could have had a rather large solar array with slide out "wings" and actuators to move them in and out.

If I had known in 2005 what I know now, I would have moved to a 48 volt battery bank.

Having a beer budget is quite a pain sometimes * grin *.

P.S. I have no relationship with *any* company that is selling anything.

SiO2 are not perfect. No battery is. But with a potential 16 year life span, and my recent change back to part time, they essential for me at age 72, have a life time guaranty. Their cost per cycle, lower initial cost, and the flat dead 620 times are icing on the -40 cake.


Thanks Don! Makes sense if your AGM's are still working, no sense replacing them before they're time is up. Interesting regarding getting the cell tower batteries. Didn't realize they ran on those. I assume they are a back up power source and are swapped out as part of routine maintenance.
And I do thank you for your postings re the SiO2's. I'd not heard of them and am completely ignorant when it comes to TC electrical, batteries and solar so rely heavily on the experience and info sharing of others. So again, thank you. [emoticon] Good to have a Canadian source for info too since availability for us can vary greatly compared to south of the boarder. As well as limited selection.


"> 1998 GMC 2500, 10.5 Okanagan, My better/smarter half, George and Finnegan(APBT), all I need.


grizzzman

salt lake city, Utah

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Posted: 09/12/20 12:27pm Link  |  Quote  |  Print  |  Notify Moderator

Itinerant1 wrote:

If a person discharges a lfp 100% without proper protection they might deserve to have an expensive brick and doing it 25 times is just idiotic.

Pianotuna are you going to test the 25 times bone dead depletion with no harm to the batteries, I won't hold you to the 620 times. [emoticon]


LOL I agree. And really the price has come down if you are into a DIY set up.( Although a person in the know says they will jump up in the next little while.)


2019 Ford F150 EcoBoost SuperCrew
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Boondocking is my Deal

Bert the Welder

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Posted: 09/12/20 12:31pm Link  |  Quote  |  Print  |  Notify Moderator

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?

Itinerant1

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Posted: 09/12/20 01:28pm 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?

Folks are either moving them inside to the heated/ cooled area or adding warming pads underneath them. You might have to take that into account and possibly add a battery for the warming pad.

I insulated the front compartment as bet as possible, added a 1/2" thick rubber mat under the batteries to get them off the metal floor and added a heat duct to the end of the duct work that ended right above the batteries. If it gets down into the teens then I'll open the heat source to the compartment. I can see cell temps on all 20 individual cells to see if warmer temp is needed.

pianotuna

Regina, SK, Canada

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Posted: 09/12/20 01:54pm Link  |  Quote  |  Print  |  Notify Moderator

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%.

* This post was edited 09/12/20 02:03pm by pianotuna *

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