Motor vehicles are usually powered by lead-acid batteries. However, a new player has recently begun showing its power in the automotive battery sector: lithium polymer batteries (such as LiFePo4's).

What are the advantages and disadvantages of replacing traditional lead-acid batteries with lithium batteries in automotive applications?


1 Answer 1


Some advantages:

  • Better tolerance for deep-discharge, meaning you don't reduce the lifetime of a battery by accidentally leaving the lights on
  • Reduced weight, and thus improved fuel economy
  • Reduced size, saving space in the engine compartment
  • Longer lifetime when only partially charged, allowing keeping the battery slightly below full charge and then quickly charging when engine braking
  • No lead, which makes the batteries more environmentally friendly

As well as some disadvantages:

  • More likely to start a fire (although LiFePO4 is reasonably safe)
  • Higher cost
  • Voltage not exactly the same, affecting e.g. halogen bulb lifetime (but this aspect will go away with LED lights)
  • Not as well-tested in float charge applications as lead acid

Personally, I believe that the 12 volt system will continue to use 12V lead acid batteries (but perhaps transition from flooded to AGM), but cars will transition through hybrids to plug-in hybrids and the high-voltage batteries will ultimately use LiFePO4. For example, all Toyota's hybrids have a traditional lead-acid battery as well.

  • What's flooded and what's agm?
    – JoErNanO
    Feb 6, 2017 at 20:25
  • Flooded means the battery has liquid electrolyte (it may or may not also have means to fill it up with distilled water), and AGM is absorbed glass mat, where the electrolyte is absorbed in a glass mat (obviously, given the name!). AGM is newer technology and more expensive but should be more durable.
    – juhist
    Feb 7, 2017 at 14:51

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