[Marty in NY]

Originally Posted by jad03060

One of the SIBs indicated that the 48vdc battery won't be charged unless the applied voltage/current exceeds 20A, which is over what most battery tenders can product (most are in the 4-10A range).

I believe its this SIB that you were referring to: SIB 61 01 21 MC-10202468-9999 48v Battery Maint.pdf

Originally Posted by TurtleBoy

It doesn't remove it from the charging circuit but rather deactivates it from being able to supply power. As mentioned above, if the charger is powerful enough the 48v will be charged with the hood open.

Thanks TB, my head was wrapped around the battery disconnection I did while performing work a while back. The attached SIB, in part, says.. ..

a) The 48 V battery does NOT charge when using a 12 V battery charger with the hood closed.
When charging the vehicle using a 12 V battery charger, the 48 V battery is ONLY able to charge with the hood open.

b) Trickle chargers and solar chargers may not be able to properly maintain the 48V battery to jad03060s point

c) Prolonged used of the “Emergency charging function” causes the 48 V battery to become totally discharged. This occurs when the 12 V battery is not properly maintained and the SOC of the 12 V battery
drops below the critical threshold value while the vehicle is in sleep mode. The vehicle is woken up and recharged from the 48 V battery. If the 12 V battery is not properly maintained, this cycle repeats until both batteries become totally discharged.

JA-06, I stand corrected and the important point is even with the hood open, the battery charger needs to be able to supply at least a 20a in order to start charging the 48V battery (which are quite pricy by the way)