Forum Discussion
- StirCrazyModerator
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 - pianotunaNomad IIILiFePo4 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) - StirCrazyModerator
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 - StirCrazyModerator
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_tonsExplorer III
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 - pianotunaNomad IIIThe 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. - pianotunaNomad IIISteve,
Where do you see the capacity curve for LiFePo4 vs SiO2? I'd love to see the graph. - StirCrazyModerator
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_tonsExplorer III“ 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 - StirCrazyModerator
pianotuna wrote:
3 tons wrote:
"
“Should not charge/discharge below 32F”.
Wrong, in most cases LiFePo4’s can be discharged to about -4f, (e.g. BB, et al) and can be charged below 32f, but at a much reduced amperage. Though my LFP is interior mounted (by a repurposed battery box), in many cases one should be able to do this passively via solar due to seasonally reduced winter harvest.
3 tons
3 tons the quote from the article qualifies itself:
"Keep battery temperature above 0 C (32 f) when discharging if possible"
I agree with the -4 f (-20 c)
I don't know why the seller's site is so negative about LiFePo4. It would seem to be bad for business. I do wonder if it is a "wiggle" on warranty??
they probably make more profit off the other types. I have hit this in stores with other products where they steer you towards there biggest margin brands or types of objects and make the lower margin ones seam inferior. the other comon problem I run into is the old store owner that hasnt kept up with technology and cant believe anything new would be better than what they have been using for 80 years... ;)
Steve
About Technical Issues
Having RV issues? Connect with others who have been in your shoes.24,189 PostsLatest Activity: Jan 21, 2025