About this replacement
Jandy E33 EOS Wireless Remote — 3.7V Li-ion Replacement Battery (24-0209)
This 3.7V 1800mAh Li-ion battery replaces the OEM cell (part no. 24-0209) inside the Jandy E33 and EOS wireless remote used in residential pool automation systems. The remote controls pumps, heaters, and scheduling features without a wired connection to the control panel. When the original cell fades after two to three seasons, this replacement restores full wireless function.
- E33 and EOS remote compatibility: Both the E33 and EOS remotes share the same 3.7V cell format, connector pinout, and BMS handshake protocol — one battery fits both units without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the E33 remote platform. The BMS accepted the cell immediately, reached full charge voltage without fault flags, and held stable output across polling intervals.
- Pool environment storage tip: If the remote sits unused through winter, pull the battery before storage. A fully discharged Li-ion cell left in a sealed remote in a pool shed can drop below the BMS recovery threshold after six months and may not accept a charge on reconnection.
Why the E33 remote loses connection to the Jandy control panel after a battery swap
The E33 remote runs a mesh re-join sequence every time power is interrupted — including a battery change. After inserting the new cell, the remote transmits a re-association request to the control panel, which can take 30 to 60 seconds to complete. Pressing buttons during this window causes the remote to queue commands that the panel hasn't yet acknowledged, which looks like an unresponsive remote but isn't. Wait the full 60 seconds before testing any function.
Low battery alert showing immediately after fitting a new cell
A new Li-ion cell shipped from a warehouse can sit for months and arrive at a resting voltage around 3.5V or lower — below the threshold Jandy's firmware uses to clear a low battery warning. The alert is triggered by voltage, not by capacity, so a partially discharged new cell will still show the warning. Place the remote on charge for a full cycle until the indicator clears. Once the cell reaches 4.1–4.2V resting, the alert drops and does not return.