GT3vsGTR

I just took delivery of a new to me 2018 GTR but prior owner did not leave the trickle charger. What is the best charger to buy and if it is the MB charger, does anyone have the PN?

Bonus question: what is the area under the the rear latch that is indented and has a couple of velcro straps. It would appear something should be stowed there.

streborx

Many forum members recommend the MB branded C-Tek charger. I use Noco chargers -- I have 3 of them. I use a 10A for fast charging, a 1A for maintaining, and a 2x2A for a winter store car. The 1A sells for bout $35 at Autozone.

dbrad32

I’ll tell you from experience and having to buy a new battery for $2000 you must use the MB CTek that came with car.

superswiss

https://www.juicemyride.com/collecti...z/model-amg-gt

These guys seem to know what they are doing. They used to sell the CTEK OE charger w/o the OE logo, but now have their own charger. This thing restored my AGM battery in my C63. My previous charger kept indicating the battery was faulty and it drained to 20%. After hooking it up to this guy, it fully charged and keeps a full charge for much longer now. The only strange thing is that you seem to have to add the lithium mode when ordering for the GT. I didn't check that box, but the charger they sent me still has the lithium mode.

streborx

I'm sure I'm not the only one curious about your experience with a non -Ctek charger and $2000 battery.

superswiss

Probably used a charger that didn't support lithium batteries.

Wolfman

IIRC, the MB trickle charger that came with our GTC was a C-Tek model that supported both types of batteries and needed to be set to lithium.

superswiss

Yep, the OE charger is a standard CTEK with lithium mode, MB logo and twice the price. Nothing special about it. Any charger with lithium mode will do, provided one uses the correct mode. Each battery type has different voltage and charging profiles and using the wrong mode can damage the battery. Especially lithium batteries are very particular about charging. They don't like to be pegged at 100% charge and will last longest if kept between 20-80% charge. They also don't need desulfation.

EDIT: Also, when it comes to car batteries, the 12V batteries don't generally have battery management logic built-in, so the external charger is hooked up straight to the raw battery and is expected to manage the charging profile. So you better set it to the correct battery type. This is different from your typical electronic device that you are charging regularly. The USB chargers we all use are technically not chargers. They just supply power. The device itself has the charger and battery management built-in to ensure optimal charging of the battery. For example iOS devices have long had a feature called optimized battery charging. It aims to learn one's charging routine and then with the lithium battery longevity in mind, it avoids the battery being kept at 100% charge for extended periods, for example if you typically charge overnight. Instead it charges the battery to 80% and then only resumes to a 100% shortly before the phone is typically taken off the charger. Below you can see what this looks like. This is how my phone charged last night. You can see how the battery is kept at 80% until a couple of hours before I took it off the charger. The battery in my phone is over 5 years old now. It has finally dropped to 80% capacity, but for now it's still working. Time to get a new phone soon, though. How the battery is charged can make a big difference.