the battery on my e300 is dying way faster than it used to, only goes like 2 miles now.

Diagnosis

Battery capacity degradation. The sealed lead-acid batteries in the E300 lose capacity over time and with use, especially if they've been deeply discharged or stored empty.

How to Fix It

Replace the battery pack. It's a single, proprietary unit.

1. Remove the deck by unscrewing the four Phillips-head screws.
2. Disconnect the red and black main power connectors from the old battery.
3. Lift out the old pack and insert the new Razor E300 replacement battery.
4. Reconnect the power connectors (red to red, black to black).
5. Replace the deck and charge fully before first use.

If That Didn't Work

If a new battery also dies quickly, the controller might be faulty and drawing excessive power even when idle.

Heads Up

Always charge the battery after every use. Letting it sit dead for months permanently kills lead-acid batteries.