So this warning popped up on my dash last week and I've been ignoring it because the car starts fine, but now I'm getting nervous. From what I've read, newer Mercedes have a main battery under the hood or in the trunk plus a smaller auxiliary battery that handles things like stop/start and the electronic parking brake. The message specifically says "auxiliary battery malfunction" not the main one. A friend told me I can still drive like this but eventually the stop/start will stop working and I might get more warnings. I called the dealership and they quoted me something ridiculous – like 1200 just for the little battery plus labor. Started looking around and found that Mercedes Battery Replacement Dubai is way cheaper if you go to a specialist instead of the dealer. My question is – has anyone here just ignored the auxiliary battery warning for a while? Does it affect anything else besides stop/start? And do I really need to replace both batteries at the same time or can I just do the auxiliary one now and the main one later? Trying to budget this without breaking the bank.