# Low battery alarm and no solar power yield **URL:** \ **Category:** Q&A and troubleshooting\ **Tags:** mppt, multiplus-ii, beginner, cerbo\_gx\ **Created:** [21 September 2025 11:09 UTC](https://community.victronenergy.com/t/low-battery-alarm-and-no-solar-power-yield/45741 "2025-09-21T11:09:38Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![frank.ren](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/frank.ren/32/1302_2.png) [@frank.ren](https://community.victronenergy.com/u/frank.ren)\ **Post date:** [21 September 2025 11:09 UTC](https://community.victronenergy.com/t/low-battery-alarm-and-no-solar-power-yield/45741/1 "2025-09-21T11:09:38Z")
Hi everyone, I have the following system all connected to a Cerbo GX - Two SmartSolar Charger MPPT 100/20 48V - MultiPlus-II 48/3000/35-32 (ACOut2 switchable) - One Pylontech US2000C The system has been working for two years. Recently, I upgraded Cerbo GX to v3.66, Multiplus II to v558, and MPPT to v1.68. Now, I got a low battery alarm, even though the battery is full. And, the MPPT’s don’t generate any power. Any clue what could be wrong? ---
**Author:** ![frank.ren](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/frank.ren/32/1302_2.png) [@frank.ren](https://community.victronenergy.com/u/frank.ren)\ **Post date:** [21 September 2025 11:51 UTC](https://community.victronenergy.com/t/low-battery-alarm-and-no-solar-power-yield/45741/2 "2025-09-21T11:51:26Z")
The following might be similar issues: > [@Low battery alarm keeps coming back](https://community.victronenergy.com/t/low-battery-alarm-keeps-coming-back/45700): > > Hello! Victron Multiplus II / Cerbo MK2 / Pylontech 5000 Entire system is visible batteries charged to 100% but the Multiplus keeps giving a low battery alarm and switches off. Any suggestions as according to the installed settings it should work properly. Thanks!!! > [@Low battery warning after MultiPlus firmware upgrade to ver. 552](https://community.victronenergy.com/t/low-battery-warning-after-multiplus-firmware-upgrade-to-ver-552/10156/2): > > Did you check all settings of the MultiPlus with VE.config? I have checked my VE.config. It follows [Victron & Pylontech UP2500, US2000, US3000, US2000C, US3000C, US5000, US5000B, UF5000, Pelio-L, UP5000, Phantom-S, Force-L1 & L2 [Victron Energy]](https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom#veconfigure_settings) The battery voltage reading from the MPPT is between 52.60 and 52.70. From Cerbo GX is between 52.30 and 52.40. ---
**Author:** ![frank.ren](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/frank.ren/32/1302_2.png) [@frank.ren](https://community.victronenergy.com/u/frank.ren)\ **Post date:** [21 September 2025 12:22 UTC](https://community.victronenergy.com/t/low-battery-alarm-and-no-solar-power-yield/45741/3 "2025-09-21T12:22:56Z")
Inspired by the following disucssion, I changed ESS mode from Optimised (with BatteryLife) to Keep batteries charged. The two MTTP’s shortly ramped up to generate power. Then they were throttled. One is shutdown complete, the other only generates 40W. > [@Photovoltaic System Drawing 100% Energy from the Grid Despite Full Batteries and Sunny Weather](https://community.victronenergy.com/t/photovoltaic-system-drawing-100-energy-from-the-grid-despite-full-batteries-and-sunny-weather/12870/3): > > Hi, my settings are set to Optimized (without BatteryLife) with a minimum SOC (unless the grid fails) at 20%. The issue is shown in the attached images: Image 1: Mode is set to “ON,” and as you can see, the energy is being drawn only from the grid. Image 2: Mode is switched to “Inverter Only,” and suddenly it starts drawing energy from the panels and the battery. Thank you for looking into this! Let me know if you need more details. blush A few more observations… ---
**Author:** ![ron\_h](https://avatars.discourse-cdn.com/v4/letter/r/ed8c4c/32.png) [@ron\_h](https://community.victronenergy.com/u/ron_h)\ **Post date:** [24 September 2025 18:32 UTC](https://community.victronenergy.com/t/low-battery-alarm-and-no-solar-power-yield/45741/4 "2025-09-24T18:32:56Z")
After updating to V558 all mine settings are gone and ESS assistant (VEConfig) was not valid any more. Think your settings are also changed and do produce low battery error ---
**Author:** ![frank.ren](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/frank.ren/32/1302_2.png) [@frank.ren](https://community.victronenergy.com/u/frank.ren)\ **Post date:** [29 September 2025 12:06 UTC](https://community.victronenergy.com/t/low-battery-alarm-and-no-solar-power-yield/45741/5 "2025-09-29T12:06:13Z")
Thank you, @ron_h. I did remember to do VEConfig. The source was found. It was the black DC terminal got fried.