Forum Discussion
StirCrazy
Mar 02, 2021Moderator
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
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