41.7 (42v) volts is bulk mode charge rate for a 36v pack.
What is your pack voltage sitting at?
Do you have some 12v SLA's handy?
I would like to see your BMS and how many B wires connections it has, and if you dare take a look at the cell voltages.
41.7V will be the final float/trickle charge voltage which keeps the pack fully charged
(Each of the cells should stabilise at ~4.2V).
These chargers usually works on a two stage principle:
Stage 1 Constant current During this stage, current is supplied at a safe, continuous fixed level until the battery voltage rises to the required maximum setting.
When the maximum voltage setting is reached, the charger will automatically switch to the next stage.
Stage 2 Constant VoltageDuring this stage, the current is automatically adjusted
(slowly reduced) in order to keep the battery voltage at the pre-set level (usually the safe maximum voltage level).
When the charging current falls below a certain level, the green LED will light up indicating that the battery is fully charged, but it will continue to supply enough current to ensure the pack remains fully charged.
In theory it should be safe to leave the charger on continually when the battery is not being used, but I would prefer to use a plug in timer to limit this to an hour each week during storage just to play safe
(and also extend the chargers life).
By doing this, the battery should always be at least 98% charged ready for immediate use, and should not deteriorate unnecessarily during the winter.
My timer also has a countdown function, so I should be able to set it for a full 10 hour charge after a long run and leave it to automatically charge and then return to the pre-set weekly charge mode, but unfortunately it seems to switch off automatically at midnight.
Alan