Why am I not able to Install a Backup Battery for my GI 275 EIS?

Per the STC a backup battery is not approved for a GI-275 that is configured to display engine information. The reason behind this is because the battery circuit design does not provide enough power for the GEA 110 or the GEA 24. So, if power is lost, the GI 275 would stay on, but all indications would go away since the GEAs wouldn’t be powered.

See the product page for more information on the GI 275
Watch this video for more information on the GI 275.