Colleen, nice work. Assuming the charger does indeed have sufficiently rated components then the lower charge rate is indeed a plus with respect to battery life.
However, if the charger "heats up" when charging a
completely discharged battery - and if indeed it is NOT limiting the charge rate to nearly 1 amp - then the semi-conductors used in the chargers "gate circuitry" are insufficient in value or capacity. (hmmmm?)
I missed it - but did you measure the current
at the very beginning of a charge of a
completely drained battery?
Was it indeed down near 1 amp, or was it more like 1.6A?
In addition to the measuring you have performed -I used an Excel sheet in conjunction with a stop watch to to record and calculate watt/hours produced during discharge. Although it is necessary to "average" the values across x/minute periods - it is still reasonably accurate method of determining "true" battery/run time /watt hour capacity.
Thanks for getting "down to it" - the bike forums are a better place for people like you.
You get the:
Anti-Richard Cranium Award
for best post to the Lights Forum