SiO2 Battery -UPDATE 5 (Two Batts)

Edit-- might be some confusion! I did not say that it was only $300 more to get the same AH. Obviously 230 AH is more than 100AH. I already have one SiO2 (expensive) so adding another to that would also be expensive to get 200 instead of the 230 for the 6s there now. (but hard to get at--unsat) It is just that if I left the 6s in the TC I would need to get two for the MH to get back to having four there. Clear as mud?
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Not clear what Azimuth is doing for price just now. I think the prices are coming down somewhat. They still have a bunch on the shelf they just got in that are not exactly flying of the shelf. I found that if you get hold of them and do your best bazaar routine, you might get a deal.

I would not buy them at all unless you had a special need that only they can fill compared with ordinary AGMs. I hope I have made that clear in this thread--not suggesting they are better in every case. In fact IMO, probably few cases. But when needs must--yes.

My special case was I needed to run the microwave at fairly high amps wrt to the battery bank AH, and the batteries were hard to get at. So Wets are no good being hard to get at, and I had no luck before with AGMs doing that work, where they apparently warped their plates the way I was doing it, and want to keep doing that. (I have no trouble in the C doing that with four 6s, but can't do that in the TC with limited vented space for batts you can get at)

Ta Da! The SiO2 is the right answer for the TC. But not enough AH for the other loads to last a few days as with regular camping work. No problem as DW was only going to be day-running or maybe one overnight at the dog training place. Then of course-- she moved the goal posts and wants to be able to stay longer, but still use the TC instead of the C because of parking space. Well drat! So out comes the Visa card for another SiO2 to make up the AH and still be ok where it is hard to get at. At least that puts all four 6s back in the C where they belong. Oh well. :)

Just how it is in the big city! :)

BFL13 wrote:



--On price-- Azimuth is selling the 27 size 100AH at $628Can (also their US site says $449 US--which is lower at 75 cents conversion) but they have all sorts of sizes and prices.

http://www.azimuthsolar.ca/product-category/batteries/sio2/

I can get two 6s at Can Tire (they are East Penn GC15s 230 AH--an excellent 6) for just under $400 with tax, no shipping. That is nearly $300 less than the SiO2 with tax and shipping.

It could be worse --check out what Lis cost! (Way more)

Have to wait for the BC govt buy my vote money to show up or else win the Lotto I guess.

300 less and twice the AH or a little bit more usable amps. I am going to have to go back and read this all over again. I am surprised with all the other types of battery prices coming down these are still that much. lots of questions yet before I cn buy them.

Steve

Here is a video where they took SiO2 to zero volts. Every day for six months? (not quite sure)

This after 4 weeks:

https://www.youtube.com/watch?v=cawNUyLAnP8

This after 6 months?

https://youtu.be/O45eLd5YotM

It is a bit old 2012

PT, don't forget that your SOC when amps start tapering depends on the charging rate, so at 25% it would be at a lower SOC than at the 19% I was using.

I don't have a charger that can do 25 amps. Nearest I can get is my Vector chargers with their 20 amp settings (eg my 1092A with 2/10/20/35)
It happens that mine does 19 at the 20 amp setting. The charger seems to be set for 14.7v and battery voltage got there by the end.

If you are recharging on gen and stop before the battery is full--as usual with gen charging to not waste gen time with tapering amps, then battery voltage would still be under that 14.7 when you stop.

Eg, when doing a 50-90 using 14.8v charger setting, battery voltage might be 14.5 when I stop. Also there is voltage drop in there, but by the time amps taper down that becomes less so battery voltage is closer to charger voltage. Even so, you don't see battery at the same voltage as the charger until amps stop flowing right at the end of a full recharge.----You know all that, but some might not, so I want to be clear.

Hi BFL13,

I've corrected my posts to reflect your information.

Was there a reason for 19% instead of 25% for the charging rate?

Were you charging at 14.6 volts?

PT, mine didn't do that. See my test results way back in this thread. Amps started to taper at 87.5% SOC with a 19% charging rate. So charging was only "faster" between about 77-87%. from 50-77 is was the same time at constant 19 amps.

Some of the blurbs say you can charge at 3C for a limited period with no harm but the "standard" is 25% charging rate as the limit. I can't find any info on how long that 3C would be, so I don't dare try over the 25%

I suspect if you hit it with 3C, amps would taper quickly down to what the battery would accept, same as with any battery. Probably accepts more amps with a lower SOC same as other batteries too. No data seen on that.

You can go down to 20% SOC (or lower) though, so that lets you do a 20-90 instead of a 50-90 or a 50-80. That means your gen time is not being wasted by amps tapering while restoring 70% instead of just 40 or 30 % with no tapering.

--On price-- Azimuth is selling the 27 size 100AH at $628Can (also their US site says $449 US--which is lower at 75 cents conversion) but they have all sorts of sizes and prices.

http://www.azimuthsolar.ca/product-category/batteries/sio2/

I can get two 6s at Can Tire (they are East Penn GC15s 230 AH--an excellent 6) for just under $400 with tax, no shipping. That is nearly $300 less than the SiO2 with tax and shipping.

It could be worse --check out what Lis cost! (Way more)

Have to wait for the BC govt buy my vote money to show up or else win the Lotto I guess.

3 tons,

SiO2 charge much faster than traditional Lead Acid. For example, at 85% state of charge the acceptance rate for a 100 amp-hour lead acid is 12.5 amps. correction in BFL13 see his real life figures.

StirCrazy,

Price was wrong.

BFL13 wrote:

I would rather get the second SiO2 than more 6s, but it is more money. In this case, whatever the price diff would be for the SiO2 vs the two 6s, so not the whole price of the SiO2 like last time.

I am not sure if you ever mentioned itbut what do the SiO2 batteries run pricewise?

Steve

No the charge rates are not a factor. Also in the TC the SiO2 is by itself and only runs the inverter. The two 6s do all the usual 12v stuff. If I had two SiO2s they would be in parallel and run everything.

The two 6s down to 50% make 115AH while two SiO2s down to 20% would make 160AH. That is with comparable 20 hr rates 11.5 amps vs 10 amps. So the two would be as good as having one on inverter and the two 6s on the rest for operating when the inverter AH are 45 or less. (At 65 amps MW, 45 AH is 41 minutes.)

The problem is cost. Two more 6s would be much less cost than one more SiO2, even with the current sale price. The one SiO2 has already solved my inverter problem with the TC, so a second one would be just for convenience, not a real need. Have to figure out my priorities!