Charging / Not Charging Table

by: Larry Rubin

Engine (alternator) Shore Power Generator Charger Boost Switch Engine Batteries House Batteries if not charging as indicated then possible cause
1 On On On On On charging charging
2 On On On On Off charging charging
3 On On On Off On charging charging
4 On On On Off Off charging charging
5 On On Off On On charging charging
6 On On Off On Off charging charging
7 On On Off Off On charging charging
8 On On Off Off Off charging charging
9 On Off On On On charging charging
10 On Off On On Off charging charging
11 On Off On Off On charging charging
12 On Off On Off Off charging charging
13 On Off Off On On charging charging #2 bad boost solenoid
14 On Off Off On Off charging charging #1 bad isolator
15 On Off Off Off On charging charging
16 On Off Off Off Off charging charging
17 Off On On On On charging charging
18 Off On On On Off charging charging
19 Off On On Off On not charging not charging
20 Off On On Off Off not charging not charging
21 Off On Off On On charging charging #9 bas boost solenoid
22 Off On Off On Off charging charging #8 bad charger?
23 Off On Off Off On not charging not charging
24 Off On Off Off Off not charging not charging #7
25 Off Off On On On charging charging #6
26 Off Off On On Off not charging charging #5
27 Off Off On Off On not charging not charging #4
28 Off Off On Off Off not charging not charging #3
29 Off Off Off On On not charging not charging not possible (charger on but no source of power)
30 Off Off Off On Off not charging not charging not possible (charger on but no source of power)
31 Off Off Off Off On not charging not charging not very interesting!
32 Off Off Off Off Off not charging not charging not very interesting!
  • Since there are 5 separate items that each can be on or off, then there are 32 possible combinations. Of course some of the combinations are not very interesting, e.g. 32 where everything is off.
  • Mike’s note lists 9 conditions —- I have cross referenced these in the list #1 - #9
  • If the engine and therefore the alternator are on, then both battery banks are being charged (conditions 1 through 16)
  • The charger is “sourced” by shore power or the generator. If the charger is turned on, and both shore power is connected and the generator is on, then the charger is getting power from shore power.
  • Combination 10 is my problem situation in that I am not getting the engine batteries to charge