SiO2 Battery -UPDATE 5 (Two Batts)

I thought the comment from that boat guy on Li was useful. He said they work for full-timers but not for weekend warriors. I will try to cut and paste that here on Edit.

Even if I had unlimited funds, Li would not suit me. Too fussy with all that BMS and what not makes them sound too delicate, but I gather that may not be really how it is. Anyway, that's just me. YMMV.

I remember some years ago running the converter from the Honda, a Vector charger from an inverter strapped to the truck battery while idling, and solar all adding their amps just fine. You just need the various chargers to be at nearly the same voltage and all higher than the battery's voltage, and they add their amps.

"Fast charging" seems to have several meanings for folks. It does not mean way high amps as such. You have to know the acceptance rate curve along the SOC range. You can get the way high amps for the first ten minutes and then they might be the same after that, so all you did was save 10 minutes of gen time. It depends! Then as PT said, you still need a way to achieve those high amps wrt the battery bank size in AH. A big bank can mean your generator can only run so much of a charger in amps, and that's that, which miight only be a normal level of charging rate anyway, so even if the battery bank could take more, you don't have it. :) anyway, off to find that boat guy's quote---(link on back on page 6 of this thread (trawler one) page 2 of that at the bottom)

"The weak point of LFP at this time is the care and feeding needed: they want to be stored in a partial state of charge, and that is not so easily done. With LA batteries in intermittent use (like most boats) you just return to the marina, plug them in, a proper charger brings them to a float state while you walk away. LFP on the other hand, should be run down to 40 - 60% before leaving them. Then when you return next month you are starting the weekend with partially discharged batteries. Currently, that makes LFP a better fit for live aboard on the hook use where they have many advantages, vs. weekend use stored in a marina, or marina live aboard.

The carbon foam batteries seem to have nearly the same life kept in float or partial state of charge - that's why people are paying more for them. No one seems to know on SiO2."

EDIT--here is something on Li fast charging where it says you can over do it and wreck the battery from overheating. There is another one about why charging is slower than discharging C rate if I can find it again

https://energsoft.com/blog/f/c-rate-of-batteries-and-fast-charging

EDIT- " Normally high discharge rate batteries can be fast charged. However, since lithium ions are embedded in the negative electrode graphite during charging, the process of inserting lithium ions into the positive electrode during the discharge process is difficult, so the fast charge ratio is generally lower than the discharge rate"

https://www.grepow.com/page/high-discharge-battery.html?gclid=EAIaIQobChMIsNOZxqr27AIVLiCtBh3YoAphEAMYASAAEgJZWvD_BwE

Note--I find that last one might have a typo or something? Says discharging difficult, so charging is slower?

I am thinking spend number 1 will be on a modern DC-DC charger for my truck camper rig.

Ya I am that guy that would rather listen to the quiet rumbling idle of a 6.2 gas V8 doing a 'mergency charge of batteries vs the lawn mower rpm drone of my Honda "quiet generator"...

Ray at Love Your RV channel just did a couple vids on DC-DC charging from the vehicle alternator, and how running solar, plus DC-DC charger, plus generator AC-converter charging at the same time works. Yes they have Li batteries.

But yes, 1 x 100ah battery for 1 night seems to be the rule in the Dark Season.

I am kind of leaning to Lithium arn batteries, install inside the warm envelope, under a seat where it would be simple to pick them up and move them to heated storage if ever such an emergency were to arise.

Now on the other hand I can own and wreck quite a few good quality FLA batteries for the spend Li and SiO2's need.

But Li lend themselves very well to fast mechanical charging methods....

I still don't understand the high discharge rate allowed vs the lower charging rate allowed. I read about "C-rates" wrt Li but got bewildered. Something about how Li electrons mate ISTR?

The explanations for SiO2 linked earlier are less than clear too (to me) having to do with various voltages when you stop at different rates and seemed to allow for "ratio" of charge rate vs discharge rates being sometimes 1 to 1 but not clear when that is, and so when you can use the mystery 3C charging for how long instead of "standard" charging rate of 0.3C.

Beats me. Luckily I don't have to worry about faster charging, doing the recharge at home.

I thought my old 156 amps on a 458AH bank was pretty fast for acceptable gen time on the Honda 3000, and that was 0.34C, so 0.3 seems ok to me. But they claim SiO2 can be done faster (less time for a 50-90 is what I would mean by that) but I don't dare try it with my very expensive battery!

EDIT--forgot again that their 0.3C is at the 10hr rate according to a couple of blurbs, so that is really about 0.27 at the 20 hr rate for SiO2 batts. (Note that the 27 for 20 and 30 for 10 is for SiO2 and would be different for other types of battery)

Have to wait for PT to buy one and try out 3C charging and find out what happens! :)

BFL13,

Thanks for the informative real life testing.

My greatest need is for generator starting. I've killed off 2 AGM by forgetting to turn off the remote electric start.

My hope is that SiO2 will tolerate that kind of abuse (very definitely mea culpa).

So as feared, first time out with the SiO2, the scenario was not as planned for. :) Instead of an all day at the dog training place for DW and come home that evening (use the MW, but not much regular RV 12v loads) it was an overnighter.

It did run the MW as required for lunch, but after dark, furnace now on and lights, it ran the MW for supper but with the inverter alarming at 11v. Those additional loads made the voltage lower than in my testing, so I didn't test for that real life aspect. :(

Then overnight furnace etc, so by return home next day, it was resting at 11.68v , which is 20% SOC for the SiO2.(The advised lower SOC to reach without a recharge--although you can go lower) One 3 amp ceiling light was on for 6 hours = 18AH out of the "usable" 80AH for one thing. (I have swapped that lamp out for an LED! Yipes)

So it did all that, which is great, but now DW wants to use it for 3 nights in a row at times! Moving the goalposts! Drat.

So I have split the bank as mentioned way back as what to do, so now the SiO2 is just on the inverter for 120v (MW, toaster, and phone charging.) The usual RV loads are now on a pair of 6s I stole from the MH.

So I got caught with the one 100AH battery that can take high draws but is still only a 100AH batt. "One batt per night" still applies. That works in the summer with no furnace and not much light needed plus solar. I could not do the job with regular AGMs which I tried before, so I still need the SiO2 for the high draws and other advantages it has. I cannot afford to just use more SiO2s to get more AHs. So the split bank trick works using equipment I already have.

The same thing would happen with Lis of course. 100AH is still only 100AH. Only with Li you spend way more than for SiO2 and apparently only save some weight, if that matters, to get a batt that does about the same thing.

If you can get it done with regular batts, such as four 6s like in the MH for both inverter and lots of AH for lights and furnace, that is certainly the way to go IMO. That's what we do in the MH. Only got the SiO2 for this particular camper job and am not sorry I did, because it works where others would not)

I agree with PT that unless there is a weight issue, there is no need for Li when you can get SiO2 to do the same thing. However, there is no need to get either for most scenarios.

BFL13 wrote:
As I posted earlier, the one I got from Azimuth says, "Made in China" on it. A careful read of the Brampton site says they "use" and test these batts--I didn't see where they said they make them there.

Look at the green label here when you blow up the picture at the bottom right where it says "Made in China"

http://azimuthsolar.ca/product/12v-100ah-sio2-battery/

That's disappointing--I had an email that lead me to believe they were being produced in Canada. Sorry if I unintentionally mislead anyone.

FWC wrote:
I agree, that can't be the actual price. They have lead in them, and lead is a commodity that is worth much more than $6 per 30kg.

Here are more reasonable looking offerings:
MCA Battery

These look very similar to the various retail options, I would be fairly sure they are buying pallets of these (or similar) with the 'your label' option.

it most likely is the price, but... you can probably add 80-100bucks per battery for shipping and that for a min order of 60 batteries. I know when I was looking at 3.2V 280AH LiPo4 cells from china I can get them for as low as 80 bucks each but shipping on 8 of them was 400 bucks. then the company that buys 400 of them is going to put new lables on them , double the price and send them to distrubitors. then the price will be doubled again at the retailer. now if people wanted to get togeather and order 60 batteries direct you would probable be able to get them for 100-150 each landed. so quite a deal if enought prople fairly close to each other need 60 batteries.

Steve

I agree, that can't be the actual price. They have lead in them, and lead is a commodity that is worth much more than $6 per 30kg.

Here are more reasonable looking offerings:
MCA Battery

These look very similar to the various retail options, I would be fairly sure they are buying pallets of these (or similar) with the 'your label' option.

As I posted earlier, the one I got from Azimuth says, "Made in China" on it. A careful read of the Brampton site says they "use" and test these batts--I didn't see where they said they make them there.

Look at the green label here when you blow up the picture at the bottom right where it says "Made in China"

http://azimuthsolar.ca/product/12v-100ah-sio2-battery/

I am re-assured that the info on these batteries is certified by the information folks of the Chinese Army! Thanks FWC! :)

$8 each for min order of 60? I hope the poor guys in the PLA re-education camp that make these? get an extra noodle in their bowls at least once a week if the batts sell well. :(

I don't care-- I tested the one I have as noted earlier in my test results post, and it does what I want it for. I am not worried it might be some kind of fake.

That link also says you can do 3C charging. I don't understand what they mean by charging and discharging ratios, and how that works for when you can use higher amp recharging. Can anybody clarify that? Thanks.

Pretty sure they are all made in China, but BFL13 should be able to tell us.