What is a safe charge rate or voltage setting for outdoor applications with wide temperature fluctuations?

What is a safe charge rate or voltage setting for outdoor applications with wide temperature fluctuations if a temperature-sensing charger is not available?

NOTE!

There is no fixed voltage setting or current that will work. A temperature-sensing, voltage-regulated charger must be used. Anything else will damage any battery and cause premature failure! It may be possible to limit this potential by using an ambient temperature sensing charger and assuming that the battery temperature is similar to the surrounding temperature. NOTE however that the temperature of the battery will fluctuate during discharge and recharge and this fact will eventually damage the battery and cause premature failure if not controlled. If the recommended charger is not available then limiting the charge current and extending the charge time will lesson the chance of damaging the battery.