This Canadian Dollar and United States Dollar convertor is up to date with exchange rates from October 15, 2015. Enter the amount to be converted in the box to the left of Canadian Dollar.
1.2V per NiMH and NiCad cell. 2.1V per lead-acid cell (car batteries are 6-cell (12.6V) and some golf carts are 3-cell (6.3V)) Finally, multiply the voltage (V) by the amp-hour (Ah) rating of the battery/pack to get watt-hours (Wh) and then compare. For example, the Switch 8 Solar Recharger is 3.6V and 2.2Ah (2200 mAh) By multiplying those two together you get 7.92W.
You can check the health of your battery in System Profiler - look at the numbers for Full Charge Capacity and Cycle Count. Health is the percent of the original (new battery) capacity, which is 5500 mAh for a 15 MBP, and 6300 mAh for a 17. MBP, i.e. (current Full charge capacity / 5500 or 6300 * 100). Apple spec is 80% health for 300 cycles.