Why does my Mercedes EQS say the 12V battery is low and show a pile of errors?

Short answer: A '12V battery low' message or a burst of unrelated errors on an EQS usually means one of the small 12-volt batteries is weak. Have the dealer test and replace it, which owners say is a warranty job. To prevent it, keep the car plugged in at about 50% when it sits, and check the app less often.

Symptom: You see a 12V battery low message, sometimes asking you to keep the car on to recharge, or many unrelated warnings at once. The car may not wake up after sitting.

What to check first

1. Leave the car on (in drive-ready mode) for a while if it asks you to.
2. Have the dealer test all the 12V batteries.
3. When parking for long, leave it plugged in at about 50%.
4. Check the app less often.
5. Read the storage section of the owner's manual.
6. Run your VIN at nhtsa.gov/recalls.

Likely causes

1. Aging or failing 12V battery. Like a gas car, the EQS has small low-voltage batteries that wear out. Owners say a weak one causes a pile of unrelated warnings. One owner said the EQS SUV has three of them. The 12V battery is the small battery that powers the computers, locks and screens. EVs and hybrids still need it to wake up, even with a full main battery.
2. 12V not being topped up while parked. Owners say the main battery charges the 12V mainly when the car is on or plugged in. A car that sits for weeks, especially unplugged with a low charge, can run the 12V down.
3. Frequent wake-ups from apps. Checking the car in the app often can wake it up. Owners suggested checking less often.

What it usually costs

Owners report 12V replacements under warranty. Owners didn't post out-of-warranty prices.

Is it safe to keep driving?

A 12V warning means important systems could fail. If the car says not to drive, don't. Otherwise go straight to the dealer.

DIY or shop?

Storage habits are DIY. Testing and replacing the 12V batteries is dealer work. An EV's high-voltage system can stay live with the car off. Leave the orange cables, the big battery and the charging hardware to a trained EV technician.

Recalls, bulletins and complaints in plain words

• Recalls: NHTSA lists 4 recalls for the 2022-2024 EQS, and its lookup returned no data for 2025. None is about the 12V battery. 24V115000 covers 80-amp fuses that may have been manufactured incorrectly and can fail on certain 2023-2024 EQS 450 and 580s, and 24V372000 is a battery management software recall for 2024 models. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 64 keyword-matched complaints for Mercedes-Benz EQS 2022–2025 (of 134 unique complaints queried, NHTSA complaints API by model year, queried 2026-11-01; keywords: 12v, 12 volt, low voltage, battery, warning, error, dead) (NHTSA returned no data for 2 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In How can I stop the EQS from unnecessarily discharging the low-voltage battery if I don't drive it as often as Mercedes expects? on Reddit r/MercedesEQ, an EQS owner who doesn't drive much asked how to stop the low-voltage battery from draining. Replies said to leave it plugged in at about 50%, the best storage practice, check the app less often, and look up the long-term storage section of the owner's manual. An EQE SUV owner had the same drain after two months parked.
• In EQS 450 issue with battery on Reddit r/MercedesEQ, an EQS 450 owner got a 12V battery low message on startup. Owners said the 12V batteries age out like on any car, that one 2022 owner just had it replaced under warranty, and that the EQS should keep the 12V charged when parked, so a repeat points at a bad battery or charging problem.
• In 2024 EQS SUV tripping a whole lot of errors. Thoughts? Help? on Reddit r/MercedesEQS, a 2024 EQS SUV started throwing a long list of errors. Owners said this usually means a weak 12V battery. One 580 owner said the SUV has three 12V batteries and they'd had two replacements in a year and a half, and the errors cleared after a charge or a new battery.

Quick tip

If you get a pile of random errors on an EQS, start with the 12V batteries before anything expensive.

Vehicle focus: Mercedes-Benz EQS sedan and EQS SUV (450, 580, AMG), 2022-2025.

Safety / mechanic note

Warnings about low voltage mean safety systems might fail. Verify with a mechanic.