The fact it indicates " Service Battery " is a good indication to have the Battery Replaced . Add to that, from what I can find >> Retina MacBook Pro 15" mid 2015 model. The theoretical capacity of this battery when new was 8755mAh. Versus" AlsoBattery Information>>Full Charge Capacity>>1711(mAh) " See post #9 - Now at 69 cycles and 100% battery capacity. I do work mine hard. On weekends I use battery power a lot. I worked about 6 hours this past Saturday on battery power. When at work I put it on a hub that charges it and connects the two 27" monitors. I don't use any special apps just have lower power mode if on battery power. Battery degradation is an inevitable part of your MacBook Pro's lifespan, extend it with this new replacement battery compatible with MacBook Pro 15" Retina (Mid 2015). Factory-installed MacBook Pro 15" Retina (Mid 2015) batteries are rated to last 1,000 cycles. If your laptop won't turn on, turns off suddenly, has a "service battery" warning Battery and Power 4. Up to 12 hours wireless web; Up to 10 hours iTunes movie playback; Up to 30 days standby time; Built-in 54-watt-hour lithium-polymer battery; 45W MagSafe 2 Power Adapter with cable management; MagSafe 2 power port; Electrical and Operating Requirements. Line voltage: 100-240V AC; Frequency: 50Hz to 60Hz Memory 8GB of 1866MHz LPDDR3 onboard memory Configurable to 16GB. Storage 1 2.7GHz - 128GB 128GB PCIe-based flash storage 2.7GHz - 256GB 256GB PCIe-based flash storage 2.9GHz 512GB PCIe-based flash storage Configurable to 1TB flash storage. Size and Weight Height: 0.71 inch (1.8 cm) Width: 12.35 inches (31.4 cm) Depth: 8.62 inches (21.9 cm) Pengujian dilakukan oleh Apple pada bulan April 2015 menggunakan sistem MacBook Pro 15 inci berbasis Intel Core i7 quad-core 2,2 GHz dengan penyimpanan flash 256 GB dan RAM 16 GB praproduksi. 1GB=1 billion bytes; actual formatted capacity less. Wireless web testing conducted by Apple in February 2011 using preproduction 2.7GHz dual-core Intel Core i7–based 13-inch MacBook Pro units. The wireless web test measures battery life by wirelessly browsing 25 popular websites with display brightness set to 50%. MacBook Pro with Retina display; MagSafe 2 Power Adapter; AC wall plug; Power cord; Configure to Order. Configure your MacBook Pro to order with these options, only at the Apple Online Store: Up to 2.6GHz quad-core Intel Core i7 (Turbo Boost up to 3.8GHz) with 6MB shared L3 cache; Up to 16GB memory upgrade; Up to 1TB of flash storage 1 tsk2Bu.