SL55/63/65/R230 AMG: Lithium battery replacement - success!
https://amperetime.com/products/ampere-time-12v-50ah-lithium-lifepo4-battery?gclid=Cj0KCQiAmeKQBhDvARIsAHJ7mF5EwQw2CDB5 sNplD0rUn05WuwLXjr0eCzYt4ep9qnlJqjBVD3l6tCIaAnHGEA Lw_wcB
It’s early doors with it, but the experience so far is excellent. Firstly, it’s 40lbs lighter. That’s a big number. Second, the old battery was dead if I left the car for 4-5 days without driving. With this one I’ve left it six days and the top flies up and down.
It’s only been a few weeks, but no downside yet, and it’s small enough There’s a space for my toolkit next to it, which means it doesn’t clunk against my trunk tank over the bumps… ;-)
I have already replaced the front battery with a Braille 21, which saved me some weight in the front, and tried to put the same in the back, but it’s not a deep cycle battery so it only lasted a day without charge. This one’s brilliant.
My 2¢….
Hey Tim, I used these ones:
Worked just fine for me. Update on this, my battery hasn't gone falt once and I've left the car sitting for a few weeks at a time. You'll probably need some straps to keep it tight too, and I got them on Amazon also.
Hope this helps!


Do yourself a favour and upgrade to modern tech, it's a better solution. Holding up completely fine.
Trending Topics
If you simply swap the consumer battery in your Mercedes over to a lithium battery you risk damaging several expensive components including the alternator, battery control module and the lithium battery itself. In the worst case scenario you could start a fire in your car.
The charging profile for a lithium battery is very different to an AGM battery (which in turn is different to a standard lead acid battery). You will see that on a decent charger like the Noco 10, there are different settings depending on which type of battery you are charging. A lithium battery has 2 distinct charging phases - first constant current and then constant voltage. The voltage regulator in your car alternator ensures that it provides a constant voltage which is what a lead acid battery needs BUT....the alternator has no control over the current. It will provide the current that is asked of it. If you sit a lithium battery in the back of your Merc and let it run down....and then attempt to charge the lithium battery via the alternator by driving the car, you are potentially putting a MUCH larger current through the alternator windings, the BCM (battery control module) and the connecting cables than they were designed for. When I first got my EcoFlow delta lithium battery pack (an amazing bit of kit) I once accidentally used a cheap Chinese mains charging lead instead of the lead than came with the unit - the leads look identical. I almost set fire to the house because the lead melted and started to burn a hole in my carpet.
If you own an R230 you have no doubt heard the horror stories of the BCM melting and catching fire. I am convinced that this only occurs in cars where someone has attempted to charge the starter or consumer battery WITHOUT disconnecting them first...or they have used a sub standard trickle charger not designed for AGM batteries or worst of all have tried to jump start the car via the consumer battery. Imagine what the huge current associated with charging a flat lithium battery might be doing to your BCM. The degradation of electrical components to the point of failure, is like shoulder barging a locked door...it might not break the first time, but eventually repeated abuse will lead to failure. Repeated voltage spikes in your BCM will eventually kill the components which are designed to protect the rest of the BCM from excess current/voltage.
As well as potentially ruining your car, you will also ruin a potentially expensive lithium battery if you dont charge it with the proper profile. My Ecoflow delta Lithium battery pack charges to 80% of its capacity in about 20 minutes which is amazing, but then, it switches to a different charging profile. The cooling fans switch off and the last 20% is done at a much more leisurely pace.
Last but not least, the AGM battery in the trunk of your car should be drawing no more than about 58 milliamps after the car has gone to sleep. At this rate a fully charged battery will easily last 2-3 weeks. Many R230 owners have a parasitic battery drain that they are unaware of. You can ruin a perfectly good AGM battery in a few months simply by letting it run flat (11.8v) and them hoping the car will be able to charge it on a short run. It can take 24-48 hours with a GOOD charger to fully charge a flat AGM battery.
If you are suffering from Consumer Electrics Offline message, there are 4 videos on the subject which may help you in this playlist:
Kind regards,
Mike
Do yourself a favour and upgrade to modern tech, it's a better solution. Holding up completely fine.
The Best of Mercedes & AMG


