This is a timely issue since I talked to a West Mountain Apps person yesterday at the St. Charles, IL hamfest. I use the CBA-IV tester at 7.5 amp discharge to run a test that will take about 2 hours. My results for that discharge rate is 12.5-13 amp hours, exactly as predicted by manufacturer specifications for these batteries.
In general all battery makers specify 5.5-6 amps as max charge current. With smart chargers, the cycle will check for battery charge state at regular intervals and will back down charge current to fit the profile for our batteries. In checking several chargers I have found start currents at near 6 amps and within a few minutes they will back down closer to 5 amps. The charge current will back down throughout the charge cycle.
Do not believe the charging is killing our batteries, it is the discharge during a match. These batteries have a predicted charge/discharge life of 1200 cycles. With the rapid high current discharge during a match, we reduce that life to about 400 cycles, typical. Remember, each CIM motor is 131 amps in stall, or each time you robot starts moving.
Virtually all batteries are made by just a few manufactures, how many is a trade secret. That means that internally they are very similar. Any differences in the specifications (amphour, discharge current, life span) should be examined against other manufacturers. At least one Chinese manufacture lists their battery as 20 amps hours because they test it at different load currents.
If you choose to purchase a West Mountain analyzer (or other products like wire or APP connectors), please let them know you are on a First robot team. I have talked to them in the past about robotics and I want them to know the impact they are having. In speaking with them yesterday I found that there is an extended software package that is optional. It allows testing to be configured for periodic high current and low current testing. This is a normal load for ham radio where when transmitting the battery is required to give high high current while when receiving the current is vastly reduced. Ham operators like to predict how much battery they have when they are operating portable (in the field, parks or camping).