Field Impact Notice- 48V Batteries

EG4 Eric · 2026-01-14T14:52:43Z

Summary EG4 48V batteries that have been sitting idle connected to an EG4 inverter will have a small parasitic draw that is too low powered to be registered as power leaving the BMS. Over time this parasitic draw can drain the battery of stored energy while in an idle state, without the ESS recognizing the change to the SOC of the system. Customer Impact Affected customers may experience a rapid drop in battery SOC when turning on loads that require a greater draw from the battery. In some instances, this rapid drop can push the SOC under the shutdown percentage, leading to complete system shutdown and loss of power. Resolution The latest 48V battery Firmware from EG4 has been designed to perform a periodic voltage check of the internal battery cells to update system SOC. This voltage update will trigger an SOC decline and subsequent recharging before bulk SOC decays to a shutdown level. Affected customers should update to the latest FW as listed below: 314Ah Indoor: Z03T17280Ah Indoor and Outdoor: S02T25Lifepower4 V2: S02T34LL-S 48V: S02T34

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Last Post by SQ671 2 days ago

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SQ671

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I wish I had seen this post prior to updating my batteries... Same issue as described. I upgraded both RS485 and RS232 firmwares to Z02T28 & S02T25, respectively, to hopefully resolve my previous issues (SOC drift, constant inverter relay opening/closing when batteries reach 100%, batteries not discharging when batteries reach 100%, etc.). Don't know if the original problems persist (just updated today), but now info of only 1 of 3 all weather 280ah are showing (site shows Battery 2 - ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ - V 2.28, app shows it as Battery0 -ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ -2.28)...

I guess I'll switch back to lead-acid mode again until a solution is provided.

Posted : February 15, 2026 7:23 am

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