Knowing the Difference
Just a note of clarification.
A Ground Power Unit or GPU is not a Battery Cart.
A Battery cart is just that usually two 12volt batterys tied together supplying at best 24v. whereas a GPU is a power unit that can be regulated and adjusted for both volt and amperage requirement.
If you note in some AFM's they specifically say that when you use a GPU the battery should be in the OFF position however, when you use a battery cart you normally have the battery switch on during the start.
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