How To Ruin Your Electric Car's Battery - LFP Edition!

there is a ton of misinformation out there when it comes to the hottest battery chemistry in the electric car world lithium iron phosphate or lfp the f is silent while the electric car market is currently dominated by nickel manganese Cobalt or nmc batteries it's expected that lfp will surpass nmc by the year 2028 a not too distant future from a consumer standpoint one of the most common questions is under understandably what are the best practices for ensuring my electric car's battery lasts as long as possible the answer to this question changes depending on the chemistry of your battery now I already have a video explaining best practices for nmc chemistries which is absolutely worth checking out in this video we're going to be focusing on lfp batteries and boy oh boy is there are a ton of conflicting information out there with that said a brand new study does a great job of explaining how and why these batteries lose capacity over time which leads to logical best practices and you may be surprised by these considering what car manufacturers are saying you should be doing so let's start what they're saying you should do take for example Ford's electric crossover the Mustang Machi and first off a huge props to Ford here because they make it a completely painless process to understand what battery chemistry the vehicle has quoting the owner's manual if the eighth Vin digit is a four or five you have a lithium iron phosphate lfp battery and if there is any other digit or letter you have the nickel Cobalt manganese NCM style battery every single electric car maker should be making it this easy to understand what chemistry your battery is now Ford's chemistry strategy isn't uncommon Tesla's is very similar where you'll find lfp batteries in standard or lower range vehicles and nmc batteries in extended or higher range vehicles but again the only way you'll really know without disassembling the battery is to be told by the car maker so once you know it's lfp what does Ford say you should do quote set the maximum charge level to 100% and charge to 100% at least once per month to maintain range accuracy now immediately you'll notice this is the exact opposite of what you should do for nmc batteries where for daily use you want to set that to a lower char charge limit say 70% okay what else does Ford say to do with the lfp battery quote during regular use you can increase the battery life by maintaining the state of charge at 100% when storing for an extended time that the battery state of charge be approximately 50% now grammatically that last sentence is a disaster but to be fair a Ford also I not often words correct also but what are they even saying first you can increase the battery life by keeping it at 100% second if you're storing it for a long time keep the battery at 50% these are obviously conflicting statements but there's a good reason for it and so in order to understand this we need to look at the voltage curves for both nmc and lfp batteries okay so here we're looking at stateof charge versus voltage so we have the state of charge of the battery ranging from 0% to 100% And we have the voltage at the cell level ranging from 2. 5 to about 4. 5 volts here just for our diagram and we're looking at lfp in red and nmc chemistry in blue now you'll notice two distinct differences first of all nmc tends to operate at a significantly higher voltage but second of all and more importantly here for the discussion of this video lfp has a much flatter voltage curve versus nmc where it has a steeper slope so let's say you want to tell the driver of an electric car how much battery percentage is remaining well let's say your battery's chemistry is nmc and the cell level voltage is reading at 3.

7 Vols so you come across at 3. 7 you come down and boom what do you know your battery is at 50% charge remaining well let's do the same for lfp now let's say you have a voltage readout of 3.