Please note there are fake branded batteries selling online. Please check OEM for the mAH if in doubt. Protected batteries are also slightly longer due to the internal circuit. If still unsure, use reputable brand like AW, Efest, Sony...etc. Lookout for Max. Continuing Discharge Current as that what vapors look out for in a high drain batteries. Avoid Lipo batteries as it is highly volatile unless R/C is your hobbies.