For BFL13 et al... FLA vs AGM vs Li vs heated Li

[Bend]

I have no dog in this discussion. Just passing the info:

https://www.youtube.com/watch?v=iy3hga_P5YY

Interesting!

[KJINTF]

3 Tons
Now you know of someone that operates a home made 200amp 4 cell LiFe prismatic battery with no "installed" BMS. I built it from CALAB cells several years ago. It is my belief there are many others with similar installations most just not making comments here. Mine has been installed and fully operational for well over 5 years in the RV. I have a few Cell Log 8 battery monitors and audio visual alarms to help me keep and eye on the individual cells, nothing more. So far all has been wonderful no balance issues with charging or discharging. One of the best upgrades to date for our old RV.

[pianotuna]

3 tons,

I'd have to disagree about the well vetted. For example SiO2 was first developed in 1951.

I do agree and said the BMS is required. No one but a fool would use any Li "raw".

[3_tons]

pianotuna wrote:
Hi Steve,

On the same search I found this:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiawbfU75HvAhVeTDABHYfqBSYQ...

"Through experimental analysis of batteries, we draw the conclusion that LiFePO4 battery has a long cycle life, good safety attributes, a high theoretical capacity, low environmental impact and other characteristics; however, it also has many shortcomings, such as need to prevent over-charge, over-discharge, and over-temperature. Otherwise, utilizable capacity of the battery will decrease rapidly, and cycle life will reduce quickly."

Translation: LiFePo4 are unforgiving of any abuse and may bite you in the behind.

However, in the spirit of ‘no cherry picking’ context, Question, why is it that ‘context’ seems the first casualty of far too many LiFePo4 discussions- lol ??), continuing on within this very same paragraph (3.4), it also points to how damage mitigation is provided via the BMS System, thus, the article should be taken in it’s objective entirety...

FWIW, I know of nobody who operates a LiFePo4 battery without a BMS (but that’s just me...), but per the standard pattern of discourse (more often hyperbole), then this will naturally segue into a subjective amateur analysis of whether or not the BMS is ‘properly designed’ - say it ain’t so!!

Therefore, I would conclude that LFP batteries may be in fact the most ‘well vetted’ battery in the entire battery world!!

3 tons

[pianotuna]

One needs a magnificent battery management system. It is not in my skill set to design such a beast.

[pianotuna]

Hi Steve,

On the same search I found this:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiawbfU75HvAhVeTDABHYfqBSYQ...

"Through experimental analysis of batteries, we draw the conclusion that LiFePO4 battery has a long cycle life, good safety attributes, a high theoretical capacity, low environmental impact and other characteristics; however, it also has many shortcomings, such as need to prevent over-charge, over-discharge, and over-temperature. Otherwise, utilizable capacity of the battery will decrease rapidly, and cycle life will reduce quickly."

Translation: LiFePo4 are unforgiving of any abuse and may bite you in the behind.

[pianotuna]

Steve,

The high temperature information came from a seller, not a maker. It seems quite counter intuitive to me for a seller to post such negative information.

I decided to look for a more scholarly article. I searched for 'temperature at which damages starts on LiFePo4' and this is what I found.

"The LIBs, however, are still facing barriers that limit their application space [18], [41]. One of the major limitations is the impact of temperature to the proper operation of the LIBs. Generally, the acceptable temperature region for LIBs is -20 °C ~ 60 °C [42]. Pesaran et al. [43] showed that the optimal temperature range for LIBs is 15 °C–35 °C. Once the temperature is out of these comfortable regions, LIBs will degrade fast with increased risk of facing safety problems that include fire and explosion."

For my American friends 15 C to 35 C = 59 F to 95 F, and -20 c to 60 c is -4 F to 140 F.

There is no way I want any type of large secondary battery in my living space.

https://www.sciencedirect.com/science/article/pii/S1002007118307536

[StirCrazy]

pianotuna wrote:
LiFePo4 can be made to work well. Any battery bank can do that, but for LiFePo4, there are lots of extra hoops to jump through. Such as a way to limit charging from an alternator, a truly compatible converter. There are also high temperature concerns, starting at 86 f and possible low temperature "cut off" depending on the design parameters of the battery management system.

With SiO2 there are few of the above concerns.

Li prices are dropping madly. I would speculate that the DIY crowd are already almost at the point of parity in initial cost for the same number of usable amp-hours in lead acid. I did see an LiFePo4 "roll your own" for $480 using cells with cosmetic blemishes. (Grade B)

I dont see them as extra hoops, which any new vehicle with the smart altanators, I think it would be wise to do a DC-DC no matter what battery you are using. for the record neither my 5th wheel or my camper gets power from the truck due to this reason and the fact I didnt know about dc to dc chargers then, and they are normal flooded batteries right now.

that high temp concern is somthing you found on one manufactures site and i cannot find any reference to thoes temps on a official sheet, the only reference I find is 60C is the top of the opperating range. Non of the systems I have seen are refrigerated to keep them cool. but for the recors SiO2 do have a max temp of 65C so that a bit better.

and the temp cut offs, that is nothing to do with LFP but rather the BMS the company chose to run them... let me say most companys will not spend the money on a truly quality BMS that has all the fetures you can get if you build you own. the BMS if you spend the money (aprox 150 cdn) can limit the charging curent, or cut it off at any temp you chose. if can shout off the battery at a high temp or low temp, can use tempature compensated charging so it will carge at higher than 1C and taper as the battery temp gets warmer and so many other features.

for the price of LFP cells for DIY they have not changed, still in the 85-100 bucks range for a 280AH cell for grade A cells. what has change is the shipping. just over a year ago the shipping alone was 1000.00 for 4 cells to canada now it is down to under 400.00 and I suspect after covid it will proabably come down further.

Steve

[pianotuna]

LiFePo4 can be made to work well. Any battery bank can do that, but for LiFePo4, there are lots of extra hoops to jump through. Such as a way to limit charging from an alternator, a truly compatible converter. There are also high temperature concerns, starting at 86 f and possible low temperature "cut off" depending on the design parameters of the battery management system.

With SiO2 there are few of the above concerns.

Li prices are dropping madly. I would speculate that the DIY crowd are already almost at the point of parity in initial cost for the same number of usable amp-hours in lead acid. I did see an LiFePo4 "roll your own" for $480 using cells with cosmetic blemishes. (Grade B)

[StirCrazy]

3 tons wrote:

StirCrazy wrote:

3 tons wrote:
“ 3 tons the quote from the article qualifies itself:”

“Qualifies itself” how so??

BattleBorn (and every other LFP offering I’ve seen), clearly state that LiFePo4’s can be discharged to -4f, with no suggestion or implication otherwise - are we to dismiss this?? In proper context, ALL chemistries tend to get sluggish in *below freezing temps (a no brainer), so this is precisely why context matters!!

*with the possible exception of SiO2, though curiously, I’ve not found an independent (i.e. non-vendor) white paper on SiO2.batteries...

3 tons

No at 0C and below Sio2 still lose a large chunk of there capacity, actualy more than LFP but they work to a much lower temp. the graphs are out there. they dont lose as much capacity as Lead acid but lose more than LFP so there in between. still a good option if weight size are not issues and temp is. but I think if some one decided to go SiO2 they should change out there chargers also as there is no sulfication (sp) with SiO2 so will the desulphacation setting dammage them? Mind you I think anyone investing in batteries should also be investing in the charging system by having one that you can customize the settings and taylor them to your battery type. I always laugh when I see some one spending 1 or 2000 bucks on batteries but wont spend 200 bucks to hange out the charger section of the converter or there solare controler.

Steve

Agreed, those are all great points Steve, kudos Sir, I can see that you’re doing your all important homework!...I definitely see SiO2’s as a viable consideration, though it’s not been made clear what kind of SOC metering is compatible - nor sure about equalizations - maybe you have a white paper?

From the little I do know, PT is going with SiO2’s (mostly due to -40d temps), and in balance he’s surely making a great choice...

As far as LFP charging goes, I’m able to easily do this using a standard Progressive Dynamics 9245 using the optional Charge Wizard pendant set to Boost mode...Post BMS balancing regime (as verified via Victron BMV-12) I simply defeat the charger...

3 tons

I have always said in PT's situation and the way he wants it to operate that the SiO2 are the best way to go for him.

what I have also always said that in any normal situation that LiFePo4 are a better way due to several factors, more usable capacity, faster charging, way more cycles at 100% discharge than others have at 50% , 0 off gassing, light weight, small size and high discharge currents. other types may share one or more qualities but not all of them, but LiFePo4 does this while also coming in at the cheepest battery when you are looking at usable AH and life.

Steve

[StirCrazy]

pianotuna wrote:
The only graphs I can find say that SiO2 are at about 80% of capacity at -20 c (-4 f), and that LiFePo4 are about the same.

Of course if we drop down another 10 degrees to -30c (-22 f) then SiO2 are at 60% and LiFePo4 there is no graph I can find.

the graph on azmuth solar shows that at -20 the SiO2 is about 75% and different graphs I have looked at show the LiFePo4 at about 80% so not a lot of difference and on a small battery we are talking a small amount. but it also gets compounded when you can only use 80% of the capacity on the SIo2. not a hughe deal like I said just another comparason, still way better than a lead acid.

Steve

[3_tons]

StirCrazy wrote:

3 tons wrote:
“ 3 tons the quote from the article qualifies itself:”

“Qualifies itself” how so??

BattleBorn (and every other LFP offering I’ve seen), clearly state that LiFePo4’s can be discharged to -4f, with no suggestion or implication otherwise - are we to dismiss this?? In proper context, ALL chemistries tend to get sluggish in *below freezing temps (a no brainer), so this is precisely why context matters!!

*with the possible exception of SiO2, though curiously, I’ve not found an independent (i.e. non-vendor) white paper on SiO2.batteries...

3 tons

No at 0C and below Sio2 still lose a large chunk of there capacity, actualy more than LFP but they work to a much lower temp. the graphs are out there. they dont lose as much capacity as Lead acid but lose more than LFP so there in between. still a good option if weight size are not issues and temp is. but I think if some one decided to go SiO2 they should change out there chargers also as there is no sulfication (sp) with SiO2 so will the desulphacation setting dammage them? Mind you I think anyone investing in batteries should also be investing in the charging system by having one that you can customize the settings and taylor them to your battery type. I always laugh when I see some one spending 1 or 2000 bucks on batteries but wont spend 200 bucks to hange out the charger section of the converter or there solare controler.

Steve

Agreed, those are all great points Steve, kudos Sir, I can see that you’re doing your all important homework!...I definitely see SiO2’s as a viable consideration, though it’s not been made clear what kind of SOC metering is compatible - nor sure about equalizations - maybe you have a white paper?

From the little I do know, PT is going with SiO2’s (mostly due to -40d temps), and in balance he’s surely making a great choice...

As far as LFP charging goes, I’m able to easily do this using a standard Progressive Dynamics 9245 using the optional Charge Wizard pendant set to Boost mode...Post BMS balancing regime (as verified via Victron BMV-12) I simply defeat the charger...

3 tons

[pianotuna]

The only graphs I can find say that SiO2 are at about 80% of capacity at -20 c (-4 f), and that LiFePo4 are about the same.

Of course if we drop down another 10 degrees to -30c (-22 f) then SiO2 are at 60% and LiFePo4 there is no graph I can find.

[pianotuna]

Steve,

Where do you see the capacity curve for LiFePo4 vs SiO2? I'd love to see the graph.

[StirCrazy]

3 tons wrote:
“ 3 tons the quote from the article qualifies itself:”

“Qualifies itself” how so??

BattleBorn (and every other LFP offering I’ve seen), clearly state that LiFePo4’s can be discharged to -4f, with no suggestion or implication otherwise - are we to dismiss this?? In proper context, ALL chemistries tend to get sluggish in *below freezing temps (a no brainer), so this is precisely why context matters!!

*with the possible exception of SiO2, though curiously, I’ve not found an independent (i.e. non-vendor) white paper on SiO2.batteries...

3 tons

No at 0C and below Sio2 still lose a large chunk of there capacity, actualy more than LFP but they work to a much lower temp. the graphs are out there. they dont lose as much capacity as Lead acid but lose more than LFP so there in between. still a good option if weight size are not issues and temp is. but I think if some one decided to go SiO2 they should change out there chargers also as there is no sulfication (sp) with SiO2 so will the desulphacation setting dammage them? Mind you I think anyone investing in batteries should also be investing in the charging system by having one that you can customize the settings and taylor them to your battery type. I always laugh when I see some one spending 1 or 2000 bucks on batteries but wont spend 200 bucks to hange out the charger section of the converter or there solare controler.

Steve

[3_tons]

“ 3 tons the quote from the article qualifies itself:”

“Qualifies itself” how so??

BattleBorn (and every other LFP offering I’ve seen), clearly state that LiFePo4’s can be discharged to -4f, with no suggestion or implication otherwise - are we to dismiss this?? In proper context, ALL chemistries tend to get sluggish in *below freezing temps (a no brainer), so this is precisely why context matters!!

*with the possible exception of SiO2, though curiously, I’ve not found an independent (i.e. non-vendor) white paper on SiO2.batteries...

3 tons