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    Tesla 12V LTO Battery

    NOTE: This is a WORK IN PROGRESS project. So, could be risky for your vehicle. Do not try to replicate unless you know about batteries. Requires electric skills and deep understanding on what you are doing.

    Objective: LTO battery replacement for old Tesla lead (pb) 12V battery.

    Until 2022, Telsa cars used an ancient 12V lead battery from AtlasBX (Hankook) or Clarios (Varta). These batteries last no more than 3 to 5 years and are heavy. Tesla cars now use 16V NMC battery, starting from 2022.

    So, I started a project in order to replace this battery with something updated. I have explored several options:

    • LFP -> Long lasting, but not very good in low temperatures. Some kind of thermal heating is needed for temperatures under -0ºC. Requires BMS.
    • NMC -> Not so long lasting like LFP. Requires BMS and can be dangerous if not handled properly. Better thermal range than LFP, but I don't want to solder cilindric cells. Discarded due to my limited skills soldering (and a bad experience time ago with a cell crashed on my kitchen roof)
    • Sodium -> Quite similar to LFP. A good replacement for the future and not very expensive. Had problems trying to find a cell that could accommodate into box without soldering since I had to reach high C rate in order to provide enough amps for turning on. Can be mounted without BMS (only with a fuse) since can reach very low voltages without getting damage. Good at low temperatures.
    • LTO -> Ultra long lasting but expensive. Ultra safe. Very high discharge rate. Very good at low temperatures. Big enough to not require several cells to be joined. Just 6 in series. Although a BMS could be added in order to avoid cell damage just in case a deep discharge, for now I will take the risk. 200A BMS are expensive and this is an experiment. So, for now, no BMS. Just a 150A fuse. But could be added and replace balance board.

    Materials needed:

    • 6 LTO cells (26Ah, but can be others if can be accommodated to my box)
    • A balance board for at least six cells (Neey in my case)
    • A fuse holder and fuse (150Amps)
    • 6 copper busbars
    • 12 M8 nuts
    • 2 25mm2 cables (positive and negative)
    • 2 battery terminals (positive and negative)
    • Battery box (this one)

    Follow up:
    https://foro.clubtesla.es/index.php?topic=12433.0#forum