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.

[BFL13]

"so by running 50 to 80 or 50 to 90% you are just acepting a shorter battery life kinda like if you run a LFP from 100 to 0 all the time you are acepting your only going to get the advertised cycle life which is Ok as long as you are fine with that. but telling people to not fully charge with out telling them that there may be a slight trade off in cycle liffe or capacity the more they do it is not cool. a lot of new people who only know that a battery makes there lights work read this stuff and go out and buy expensive batteies then wonder why there getting killed in 3 years."

Lots of advice out there to do 50-80s when on generator recharging so not to waste generator time and fuel doing the higher SOC part with low tapering amps. Also lets you get more AH in during generator hours if those times are restricted.

Charging profiles for different battery types are useful for knowing how far up in SOC it is worth going while doing a generator recharge

When I first got onto this the big problem was knowing when the batts were up to 80 or 90 % while still being charged so I knew when to stop the gen. Voltage no use and no ammeter on a converter to tell you what amps have tapered to. That is where the Trimetric monitor came in handy with its AH counter

It is true that Newbies can have their first set of batts die too soon. Called their Learning Set. Happened to me for sure.

[3_tons]

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

3 tons

[StirCrazy]

BFL13 wrote:
With FLAs doing successive incomplete recharges in a row leads to Progressive Capacity Loss. We talked about this on here about ten years ago. You must do a "recovery" to Full every so often or your capacity gets so low you can't get through the next night. Depends on the whole scenario how many days you can do it.

Ok but dammage is done every time it is not fully charged, tiny buts of damage but dammage none the less that is not reversable. so even if you do charge to 100% your only preventing the extra bit of damage from that cycle not from the previous times you didnt get to 100%. there are desulfication methoes but they are doubious at best and don't totaly fix things if they fix anything at all.

so by running 50 to 80 or 50 to 90% you are just acepting a shorter battery life kinda like if you run a LFP from 100 to 0 all the time you are acepting your only going to get the advertised cycle life which is Ok as long as you are fine with that. but telling people to not fully charge with out telling them that there may be a slight trade off in cycle liffe or capacity the more they do it is not cool. a lot of new people who only know that a battery makes there lights work read this stuff and go out and buy expensive batteies then wonder why there getting killed in 3 years.

I agree that solar has helped but that again can be an issue of the system is sized to small and your battery reserve is to small. I have mine set up to in normal conditions to only use the top 20% of the battery bank and then once and a while dip a little lower, but my solar can recover my bank from 50% to 100% by 2pm whish is why my last batteries lasted 14 years before showing any indication they were old.

with the new LFP in the camper I only use the top 10% of the capacity as it isn't there to run everything and the solar has it charged full befor noon , but it is rather for the emercency capacity when I am in the bush and the solar isn't working for some reason (snow, rain, etc.)

[BFL13]

Grit dog wrote:

BFL13 wrote:
Whoever replied at 1521, it's not showing on mine yet. Apparently that means you are in Admin's bad books! 🙂

Wudn't me!

No, it was Lwiddis. Apparently, you both have to start behaving according to what the Truck Camper mod said. Tee hee! 🙂

[BFL13]

time2roll wrote:
More usable capacity. Full amps to 90%

If it stayed at constant 56.5 amps till 90% SOC instead, that would take 0.354 Hr or 21 minutes to do the 80-90 instead of 30 minutes as happened. Saving = 9 minutes.

(I can do the constant amps with the PowerMax 55 amper. It happens to run at 56.5 steady off the portable generator. It runs, but at lower amps off 120v below 105v. I had to get out the gen at home to do the test because of the long cord from the stick house to the camper made for low 120 with the converter on.)

"Usable" is hard to define.

I found that "usable" capacity for the case of running the inverter at high loads is when 90 amps at 50% SOC makes the inverter alarm, so that is almost 1C (the way I do that). At less of an inverter load you can go below 50% of course without inverter alarm. How low? Depends on the load amount.

I don't know how low you can go doing ordinary loads that will still run at lower voltages. DW came back with the one batt at the time at 20% SOC and things still worked, but those things pull low amps. Same as with FLA to a degree. Not as low as LFP with their slightly higher Voltage per SOC than SiO2's (which is higher than FLA and some AGMs)

How dim can the lights get and how slow can the fans go before you declare they are un-usable?

At least there is no BMS cutting you off completely. Yipes!

Anyway it is what it is. IMO they are sort of like the Stark brand AGMs I had back when, only with the high amp discharge thing added in.

I won't be cycling them enough times down to zero to see if they really last as long as the ads say. I doubt they will hardly ever get below 40% the way we operate.

[time2roll]

More usable capacity. Full amps to 90%

[BFL13]

time2roll wrote:
Seems fine although not exactly impressed. Seems more limited than what some have previously expressed.

Good to know the SiO2 is working for you.

What were you sort of expecting?

[BFL13]

Ok so at 28% charging rate tapering starts at 80% SOC
at 19% charging rate tapering starts at 87% (as expected-same idea as the ugly graph for FLA)
----------------

There is some info ? that the same happens with LFP but hard to pin down. Needs some ugly graph work! also with LFP there is another aspect where (more rumour ) something similar happens if you use a lower charging voltage. That is different from the ugly graph where the same charging voltage is used but different amps per size of bank in AH.
--------------

I found my test result on the one SiO2 back in Oct 2020 where I used the Vector at its 20 amp setting (it did constant amps at 19 amps for a 19% charging rate)

" using the same Vector charger as in my ugly graph with flooded 27DC type batteries, and a 19% charging rate, the Vector stayed in constant amps until 76% SOC Flooded and 87.5% SOC with this SiO2 batt. Amps then taper.

Not attempting to compare tapering times since with the Flooded it is very flat 90-100 but steeper for that last 10% with the SiO2. Certainly you get a "faster recharge" from 76% SOC on up because one is tapering and the other is still in Bulk constant amps for part of that range.

At the 19% charging rate used for this test, it is the same times up till 76% -can't be faster, the charger can't do faster, but eg, with the Flooded, the 80-90 part takes an hour of tapering, while the SiO2 takes about 1/2 that time then tapers."

[time2roll]

Seems fine although not exactly impressed. Seems more limited than what some have previously expressed.

Good to know the SiO2 is working for you.

[Grit_dog]

BFL13 wrote:
Whoever replied at 1521, it's not showing on mine yet. Apparently that means you are in Admin's bad books! 🙂

Wudn't me!

[BFL13]

With FLAs doing successive incomplete recharges in a row leads to Progressive Capacity Loss. We talked about this on here about ten years ago. You must do a "recovery" to Full every so often or your capacity gets so low you can't get through the next night. Depends on the whole scenario how many days you can do it.

Solar solved that by doing shallow instead of deep cycles and by getting close to or even to Full often when the sun is out. You still have to get to Full every so often and do an overcharge per battery guidelines.

Here is a plot showing PCL with five successive 50-90s I did about ten years ago.

[StirCrazy]

BFL13 wrote:

pianotuna wrote:
Ty BFL13,

Useful information.

I'd be tempted to stop at 80% myself.

Yes 40 - 80s is 40% too and save gen time

Note this is not much use with solar No constant amps and amps taper from noon as sun lowers regardless of battery SOC

Ok so I am not sure if this applies as much to SiO2, maybe some one can tell me as there is nothing showing up on a google search, but I see a lot of people only charging normal batteries to 80% all the time are you not worried about sulfication.

if you do this continuously, or even just store the battery with a partial charge, it can cause sulfating which reduces the capacity of acid batteries.

Steve

[BFL13]

pianotuna wrote:
Ty BFL13,

Useful information.

I'd be tempted to stop at 80% myself.

Yes 40 - 80s is 40% too and save gen time

Note this is not much use with solar No constant amps and amps taper from noon as sun lowers regardless of battery SOC

[3_tons]

Lwiddis wrote:
Interesting observations. TY for posting.

X2!! Thanks BFL for the good information!

3 tons

[pianotuna]

Ty BFL13,

Useful information.

I'd be tempted to stop at 80% myself.