So the ideal way to keep the clock from resetting is to install a backup battery. If you do that, you definitely don't want to connect the keep alive wire, as it will recharge the backup battery as it slowly self-discharges over time. This wasn't an ideal design, and SkyView - in contrast - only charges the backup battery when we see a high enough voltage such that we know that an alternator/generator is running.
If you don't have the backup battery, connecting the keep alive line will have much less of an impact on discharging your aircraft battery (I think it's negligible, but I don't know the current draft off the top of my head).
Another way to have the system pick up time is to connect a NMEA GPS via serial. Then, whenever you get a lock, it'll pull that into the system.