About this replacement
Seik Terra FA5-10 — 7.2V Ni-MH Replacement Battery (709053557)
This is a 7.2V 1200mAh Ni-MH replacement battery for the Seik Terra FA5-10 crane remote control. It fits the wireless handheld transmitter used to operate overhead cranes and hoists in industrial environments. OEM part number 709053557 confirms the correct fit.
- Terra FA5-10 transmitter compatibility: The FA5-10 remote uses a dedicated battery compartment sized for the 709053557 cell pack. Voltage must match exactly — crane remote receivers validate transmitter signal strength against battery output, and an undersized voltage source causes intermittent dropout during solenoid activation.
- Bench tested on actual hardware: We cycled this cell pack through repeated solenoid-trigger sequences and monitored voltage under the inrush load. The BMS held stable across the test sequence with no undervoltage cutoff events at full charge.
- Monthly charge during idle periods: Crane remotes often sit unused for weeks between job phases. Ni-MH cells self-discharge at roughly 1–2% per day. If the pack drops below the minimum threshold, the remote may appear dead on next use — a full charge before any idle period prevents this.
Solenoid activation causing power dropout on the FA5-10 remote
When the FA5-10 transmitter sends a lift or travel command, the receiver triggers a solenoid or contactor that draws a short inrush current spike. A degraded or low-charge battery can sag below the transmitter's operating voltage at that exact moment, causing the remote to cut out mid-command. This is not a fault with the remote itself — it is a voltage delivery problem. A fresh, fully charged 1200mAh Ni-MH pack maintains enough headroom to absorb the inrush without dropping below 6.0V under load.
Terra FA5-10 remote showing low-battery indicator immediately after new battery install
Ni-MH cells ship at storage voltage, typically 1.1–1.2V per cell, which puts a six-cell 7.2V pack at roughly 6.6–7.2V open-circuit. The FA5-10 firmware interprets anything below its charged threshold as a low-battery condition. This is not a faulty cell — it is the expected storage state. Connect the pack to the appropriate charger and bring it to a full charge before first use; the low-battery indicator will clear once the cells reach operating voltage.