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--- cars:batteries [2025/02/10 20:03] – created - external edit 127.0.0.1
+++ cars:batteries [2025/02/13 02:58] (current) – [Batteries] Nedra
@@ Line 1: / Line 1: @@
 ====== Batteries ======
-You will need batteries!
+You will need batteries! Batteries are governed by section 1.8 in the official rules. consult there for the most up-to-date/official determinations about technical specs.
-There is a list of 'approved' battery technology that you can use.
+Generally, you'll be selecting either Lead-Acid batteries or one of the assorted Lithium Chemistries.
-Jeremy (or someone else) will add that list below.
+Lead-Acid batteries are tempting because they are free on the BOM, but they are heavy and have a lower energy density. They are generally discouraged for new builds if your aim is to drive half-competitively, but they are a fine option for getting a "baby's first kart" off the ground and on four wheels.
-If you come up with some batteries not listed below, ask Jeremy, and he will consider adding them.
+Lithium batteries are generally higher energy density, which means a lower overall weight on your kart. since Lithium is less inherently safe than lead-acid (risk of fire) you'll have to make extra sure that you know what you're doing when you get into building your own packs, manipulating others' home-brew packs, and charging or discharging either homemade or store-bought packs.
+All chemistries which cost on the BOM are calculated in the same fashion, whether it's Ni-Cd/Ni-MH (not recommended due to poor energy density) LiPo/LiIon/LiFePo4, or other technologies: $0.06/Watt-Hour as calculated by: "Battery Sticker Amp-Hours" x Nominal Cell Voltage.
+For Example, a 12S3P Chevy Volt pack of Lithium batteries, which contains pouches stickered at 15AH per pouch, calculates as follows:
+AH x 3 cells in Parallel (3P) = 45 AH per cell.
+cells in Series (12s) * 3.7v nominal voltage = 44.4v
+.4v * 45AH = 1998 Watt Hours
+WH * $0.06 = $119.88 total battery cost on the Bill of Materials, regardless of how much you paid for it.
+This value does not degrade over time (even if you bought your batteries a decade ago and they don't hold as much energy, the BOM is still calculated off the Sticker, not a measured actual AH)
 ===== Approved Battery Technologies =====