Battery group sizes
A group size is not a capacity or a brand. It is a MAXIMUM BOX, issued by Battery Council International, that a battery sold under that number has to fit inside — with the post and terminal arrangement that goes with it. Almost every lead-acid golf cart runs on GC2, GC8 or GC12, and almost every lithium pack sold to replace one calls itself “GC2 size”.
These are BCI’s own figures, read from their published table. Each group’s page sets them against the packs whose own makers publish dimensions, so a “drop-in” claim can be measured rather than taken.
| Group | Volts | Maximum L × W × H | Post / terminal |
|---|---|---|---|
| GC2 | 6 V | 264 × 183 × 277 mm10 3/8 × 7 3/16 × 10 7/8 in | LPT,HPT,UT,LT |
| GC2H | 6 V | 264 × 183 × 295 mm10 3/8 × 7 3/16 × 11 5/8 in | LPT,HPT,UT,LT |
| GC8 | 8 V | 264 × 183 × 277 mm10 3/8 × 7 3/16 × 10 7/8 in | LPT,HPT,UT,LT |
| GC8H | 8 V | 264 × 183 × 295 mm10 3/8 × 7 3/16 × 11 5/8 in | LPT,UT,LT |
| GC12 | 12 V | 327 × 183 × 277 mm12 7/8 × 7 3/16 × 10 7/8 in | LPT,HPT,UT,LT |
| U1 | 12 V | 197 × 132 × 186 mm7 3/4 × 5 3/16 × 7 5/16 in | X |
| U1R | 12 V | 197 × 132 × 186 mm7 3/4 × 5 3/16 × 7 5/16 in | X |
| U2 | 12 V | 160 × 132 × 181 mm6 5/16 × 5 3/16 × 7 1/8 in | A3,X |
Source: batterycouncil.org/wp-content/uploads/2023/10/BCI-Group-Sizes.pdf
What the numbers are and are not
They are maxima, not targets. A battery under them still drops into the tray. But BCI also say batteries within a group “must be the same physical size (i.e., within 2mm)”, so a pack well under the maximum is worth knowing about: a hold-down bar set for a taller battery does not clamp a shorter one, and an unclamped battery in a cart is a loose object.
And the maximum height includes raised quarter covers — BCI say so — with a flat-top design running about 10 mm lower. That matters when a published height sits a few millimetres outside a group: it may be measuring to a different point rather than describing a different battery.