T&T: (Potentially) Catastrophic Electrical Shut-down

[Richard]

 The best
> explanation I've found so far is that the batteries were so close to the 
> end
> of their lives that equalizing simply killed them off. The fumes were
> evidence of the degradation of the plates. The inverter sensed the absence
> of charge in the battery banks, and went 'balls to the wall' as long as it
> could to restore capacity.

Amazing that you did not get the hint from the 'acrid air'. The instructions 
for equalize in all manuals I have seen say 'do not leave the batteries 
unattended during equalize', and most require that batteries be at normal 
fluid levels before equalize. The fumes had little or nothing to do with 
degradation of the plates, everthing to do with too little care and 
attention to the process. Once batteries go into thermal runaway, which is a 
small possiblity here, the only thing to do is complete disconnect, that is 
no charge, no load. This is also not a time to attempt adding water.

It is also possible (but unlikely) that the odor came from a source other 
than the batteries.

Many inverters have a time component in the charge cycle that will limit the 
period of time bulk charge was on. (also true for equalize). Check to see 
that the standard times have not been tampered with. The situation you 
describe was much more common with ferroresonant chargers that typically did 
not have time control on the charge cycle.

Aside from the electric fuel pump possibility, if the engine has a very 
large alternator and is a moderate size engine, it is possible the engine at 
idle was stalled by the alternator load if the alternator was fully loaded 
serving all the electric demands. I would go over every connection in your 
high amp circuitry and check for 'clean and tight' after an event like this. 
Also check on wire sizes and breaker functioning. Look for signs of burned 
wire ends especially under connectors or other areas where wires are 
'packed'.

Consider a breaker on your charge line from the alternator sized to protect 
the wire.
Richard