Tip for those disconnecting any battery:
- It is not necessary to disconnect both terminals, just the Negative terminal is enough. Once that is disconnected, the battery is essentially ‘disconnected’.
- Whenever disconnecting any battery, for removal or other purposes, disconnect the Negative first. This way you cannot short the Positive to ground.
- As a ‘just in case’ scenario, wrap the wrench or socket handle in electrical tape to avoid shorting to ground.

Shorting the battery to ground can have many adverse effects. It can damage the battery, bad enough. But with all the sensitive electronics and ECU controlled components one risks causing $$$ damage to multiple systems in the vehicle. You are extremely lucky. I would go buy a lottery ticket after that. Then have a shot and a cold beer, you dodged a bullet.