SiO2 Charging Profile

[BFL13]

56.5 constant amps in Bulk is 28% charging rate--expect lower rate to run to a higher SOC before tapering but take longer over all.



Here is the old ugly graph again showing 55 amps on a pair of FLAs rated at 220 but might have been more like 200 if they used the 1 amp instead of the 20 hr rate--don't know now. Doesn't make a lot of diff here though.



You can see the times to do a 50-90 are longer with the FLAs because of earlier tapering. Took an hour to do the 80-90 vs 1/2to do the 80-90 with the SiO2

There is some inaccuracy due to the monitor not showing any heat loss but that seems to be not much of a factor. Anyway there it is.

[pianotuna]

Hi BFL13,

The government "helped" me during covid. Now they want $8400.00 back. No SiO2 jars for me this year.

The one for my generator is working well.

[BFL13]

PT that is interesting about how the current changes the IR. (which is listed as a bit higher than an AGM's) I suspect that is poor wording for what goes on, but you do get recharged in a shorter time using the higher current for sure.

I have been using the 20 amp Renogy DC-DC setting of 14.7v and the solar is adjusted to 14.7 to match that (so they add their amps fully) to recharge while driving around and get 30 some amps total mid-day.

Solar is low amps (255w on the 200AH bank) so it is good to know the batts still get charged ok even if it takes longer and there is no minimum amps spec like that 20% for Lifeline AGMs and the 20% Trojan recommends too for their AGMs.

They are not exactly flying off the shelf at Azimuth looks like. Must be time for PT to make them an offer! 🙂

[pianotuna]

Getting the Most Out of Your Silicon Dioxide Batteries/Optimizing Your Silicon Dioxide Batteries:
Silicon dioxide batteries, AKA Lead Crystal or SiO2 batteries are designed to provide dependable power in conditions that would ruin most other battery types. They can outperform lead-acid and lithium batteries at high and low temperature extremes, charge faster than lead-acid, and don’t off-gas, or require maintenance. All that said, they still perform their best under certain conditions…
“Bulk” or “Absorption” Charging: These charge at the higher range of charging voltages for typical lead-acid batteries 14.4V – 14.7V, with 14.6V being the optimal voltage suggested by the manufacturer. Most charge controllers and vehicle alternators reach 14.4V, or just above. Some battery settings on charge controllers, such as “Flooded” or “Gel” may not reach that high, so charging could be slower and inefficient. “Sealed” “Lithium” and “Custom/User Defined” settings usually have higher available voltages and can allow for user adjustment. Maximum/Optimal Charging Current is 25% of Ah capacity. This is usually expressed as a 0.25C, C/4, or a 4-hour Charge Rate from 100% discharge. Charging at lower current is fine, but these batteries actually charge more efficiently at the maximum rate, as the higher current helps lower charging resistance of the electrolyte. This also minimizes run time for generators, and reduces fuel use, and also reduces RV and boat docking time for grid power AC charging, so you can cut your waiting time by almost half. “Float” Charging voltage range is 13.5V - 13.8V. When fully charged, these batteries have a shelf-life of up to 2 years, so float charging may not be necessary in circumstances where fuel conservation and charging from a generator is limited. Regular lead acid, lithium, and especially nickel-iron batteries require much more frequent float charge “top-ups”.
“Equalization or De-sulfation” charge settings are not necessary for these batteries. This function on multi-stage chargers should be turned off, or if it is 14.7V or less, it can be left as another Bulk charging cycle for the batteries. When the battery is fully charged, there is often an initial "surface charge" voltage generally starting at around 13.5V with no load, and will stabilize at around 13.05V after 4-6hrs. Or you can run a small load on the battery for a brief period to dissipate the surface charge for a more accurate voltmeter reading. This is common behavior with most lead-acid batteries as well. The State of Charge vs Voltage chart (attached) is for zero to minimal load on the batteries, if there is a load on the batteries, then the voltage readings will be lower. This should help you fine-tune your charging and monitoring systems to optimize the performance of your battery.

[pianotuna]

Getting the Most Out of Your Silicon Dioxide Batteries/Optimizing Your Silicon Dioxide Batteries:
Silicon dioxide batteries, AKA Lead Crystal or SiO2 batteries are designed to provide dependable power in conditions that would ruin most other battery types. They can outperform lead-acid and lithium batteries at high and low temperature extremes, charge faster than lead-acid, and don’t off-gas, or require maintenance. All that said, they still perform their best under certain conditions…
“Bulk” or “Absorption” Charging: These charge at the higher range of charging voltages for typical lead-acid batteries 14.4V – 14.7V, with 14.6V being the optimal voltage suggested by the manufacturer. Most charge controllers and vehicle alternators reach 14.4V, or just above. Some battery settings on charge controllers, such as “Flooded” or “Gel” may not reach that high, so charging could be slower and inefficient. “Sealed” “Lithium” and “Custom/User Defined” settings usually have higher available voltages and can allow for user adjustment. Maximum/Optimal Charging Current is 25% of Ah capacity. This is usually expressed as a 0.25C, C/4, or a 4-hour Charge Rate from 100% discharge. Charging at lower current is fine, but these batteries actually charge more efficiently at the maximum rate, as the higher current helps lower charging resistance of the electrolyte. This also minimizes run time for generators, and reduces fuel use, and also reduces RV and boat docking time for grid power AC charging, so you can cut your waiting time by almost half. “Float” Charging voltage range is 13.5V - 13.8V. When fully charged, these batteries have a shelf-life of up to 2 years, so float charging may not be necessary in circumstances where fuel conservation and charging from a generator is limited. Regular lead acid, lithium, and especially nickel-iron batteries require much more frequent float charge “top-ups”.
“Equalization or De-sulfation” charge settings are not necessary for these batteries. This function on multi-stage chargers should be turned off, or if it is 14.7V or less, it can be left as another Bulk charging cycle for the batteries. When the battery is fully charged, there is often an initial "surface charge" voltage generally starting at around 13.5V with no load, and will stabilize at around 13.05V after 4-6hrs. Or you can run a small load on the battery for a brief period to dissipate the surface charge for a more accurate voltmeter reading. This is common behavior with most lead-acid batteries as well. The State of Charge vs Voltage chart (attached) is for zero to minimal load on the batteries, if there is a load on the batteries, then the voltage readings will be lower. This should help you fine-tune your charging and monitoring systems to optimize the performance of your battery.

[pianotuna]

From Azmuth:


I'm just following up on your request for charging information for the
Silicon Dioxide batteries.

I have attached a few charging parameter sheets here for your reference.

Also, please see below for info on the 100Ah batteries:

- Maximum charging voltage: 14.7V

- Recommended charging voltage: 14.6V

- Recommended charging amperage: 25-30A (based on a 100Ah SiO2 battery)

[pianotuna]

Two types of damage on flooded cells.

On each and every cycle there is some shedding of material on the positive plate.

It is permanent damage and there is nothing that can be done about it.

The negative plate sheds when it is hard sulfated and recharged to "knock" this inactive material from the plates. This material falls to the bottom of the cell.

We call them plates--but it is more like a sponge on a grid.

[BFL13]

pianotuna wrote:
Hi BFL13,

Why not write azmuth about max charge voltage and amperage?

No need. The 55 amper is in the TC with 200 AH No plans to go higher in charger amps on gen

Combined solar and DC-DC is maybe 35 amps max Can switch them off if the 55 is on

[pianotuna]

Hi BFL13,

Why not write azmuth about max charge voltage and amperage?

[pianotuna]

If you really want maximum cycle life, on LiFePo4, then discharge to 45% and recharge to 85%. Once every thirty days (assuming constant use), recharge to 100% and then immediately draw the battery down.

[StirCrazy]

3 tons wrote:
My initial understanding was that SiO2’s do not sulfate, meaning that equalizations are not necessary??

3 tons

it may be that they don't, I searche for an hour the other day and couldnt find any quality info either way, but agm and regual batteries do, LFP kinda does in a way but it is a different process and it stands to make sence that SiO2 will also but at a much lower rate maybe then regular lead asid. I know the addition of SiO2 to the anode of a LFP will increase its life span also so maybe they don't but something is giving them a cycle life.

the main reason I brought this up as I have seen several other conversations where prople running GC2, AGM and other batteries are also advocating running a 50-80 % type routeen, and I think people who are new should know you can do this but it can and will decrease the capacity/life span of the battery. if you are ok with this then fill your boots.

this also applies to how I run my LFP if I have to go from 100% to 0% because of a solar issue big deal, I charge to 100% and then switch to a 13.4 float so I am floating at 99%, could I get extra life if I only charged to say 85% and nly discharged to 20% sure why not, but maybe not as my normal cycle is less than 10% of the capacity of the battery so right there with the shallow discharge I am adding a lot of life so how much does it offset my charge values....

bottom line is we should have the proper information and know both the upsides and down sides on the way we run our batteries so people can make informed choices.

Steve

[BFL13]

AFAIK the maximum recharge is listed as 27% or also seen-25% or also seen under 30%. I have not seen a "minimum" charging rate such as that 20% one for some (all?) AGMs, or to be above gassing voltage for FLAs. Not clear on LFPs--last heard it was 14.2 at least to get them to balance, but if not going for a balance then anything over 13.2? Whatever it is or isn't let the LFP guys fight it out. 🙂

If there is a minimum for SiO2s please let me know!

I use my 55 amper on the 200AH bank and am calling that as meeting the spec although it is over a tad. With one battery I was way over with the 55 amper, so I used a 20 amp portable, but no sweat with a 100AH FLA--it just accepts what it wants out of the 55.

I don't dare try that with my SiO2, because I don't know if it will damage it or if it just acts the same as a FLA

[pianotuna]

SiO2 for best lifespan need to be fully recharged once every 30 days (or perhaps cycles). My understanding is that recharge rate should be at 27% of the total capacity of the bank.

[3_tons]

Well at only 5% sulfuric acid, I’d kinda doubt that sulfating is all that significant, or something that even an occasional FULL recharge might not adequately resolve - this different chemistry may be the primary attribute to suggest SiO2’s extended longevity…JMO

3 tons

[BFL13]

3 tons wrote:
My initial understanding was that SiO2’s do not sulfate, meaning that equalizations are not necessary??

3 tons

Not sure. ISTR they have a little acid (5% comes to mind) in them even with mostly some other kind of chemistry so you still have to get them Full every so often. Would have to dig into all that stuff we looked at back in 2020 to clear that up.

Found this on Azimuth:

The non-corrosive electrolyte in SiO2 batteries forms crystalline salts when charged/discharged. SiO2 batteries use 95% less sulphuric acid than Lead Acid batteries. They are essentially a “dry-cell” battery with no liquid to freeze, spill or off-gas

Getting confusing whether it is the battery that needs to go to Full or for the monitor to reset that. Both. LFPs still both but it is to balance them and reset the monitor not to desulfate them as the reason.