in2hockey Show full post »
in2hockey
Thanks everyone for the valuable input! Looks like I need to get busy troubleshooting this thing now...  
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cookelec
78buckshot is correct with his description of the circuit. I would just add that the battery charge winding may go through a bulkhed fitting before it gets to the battery charge relay. I have found these to sometimes be non conductive. Check wires 66 and 77 for continuity across the connector if you find the charge winding voltage missing at the charger while the unit is running.
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in2hockey
Alright, I'm back on my inherited 13KW unit after the successful upgrade at my bosses place to a 45KW unit. 66 & 77 have continuity, looks like I was mistaken and it wasn't charging whether it was on generator power or utility. The DC output at the factory charger under utility power is 13.85 VDC with the outgoing harness unplugged but once I plug it in the voltage drops to whatever state the battery currently is, in this case 13.30 VDC then continues to drop and it is currently down to 12.91 VDC and continuing to decline. I'll watch it over the next 24 hrs and if it continues to drop then I think the problem is solved and it just needs a new on-board charger! Any flaws in my diagnoses? 
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Peddler
Don't often see units putting out 13.3 volts no load not keeping the battery up unless the battery is bad or there is a short somewhere.  Won't say it isn't possible.
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in2hockey
The 13.3 v was the battery voltage before connecting it to the system. It had a full charge already from my battery charger. The on-board was putting out 13.85 v until I connected the battery then it reflected the current state of the battery, which was 13.3 v and from there is continually dropping, currently it's at 12.76 v. So it's not even charging the battery while the generator is idle, I would assume that I should see at least a constant 13v at the battery and certainly no dropping.   
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in2hockey
OK, I'm going to add more to it. The step down transformer is putting out 18.79vac on lead 6&7 and 17.27vac on lead 9&10. Lead 6&7 feeds the battery charger, could this higher voltage have damaged the charger since it's looking for around 16vac incoming and not almost 19vac? Or is this an acceptable amount of overage at almost 18% more vac?
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MacL
I think I've seen one 1801 charger read good output only until a load was connected.  

It's hard to say what the voltage should drop to once the battery is connected, but whatever it drops to, it needs to be ticking upwards towards the no-load voltage.

Now you say yours ticks down despite "apparent" output at the charger module.  

I think I'd go ahead and buy the 0A18010SRV charger and give it a shot.  Worst case you'll have a battery charger on hand when it does go out.  But I'm fairly confident that it can't be anything else.
State your problem, not your diagnosis.
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in2hockey
Thanks MacL! Agreed!! 
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UPS
MacL wrote:
I think I've seen one 1801 charger read good output only until a load was connected.  

It's hard to say what the voltage should drop to once the battery is connected, but whatever it drops to, it needs to be ticking upwards towards the no-load voltage.

Now you say yours ticks down despite "apparent" output at the charger module.  

I think I'd go ahead and buy the 0A18010SRV charger and give it a shot.  Worst case you'll have a battery charger on hand when it does go out.  But I'm fairly confident that it can't be anything else.


A bad filter capacitor in the charger could cause the voltage to read higher when the battery is connected.  The battery functions to some extent as a substitute for the capacitor.  Without any filter, the resulting pulsing DC (at 60 Hz) will read low.  Some inexpensive trickle chargers with no capacitors work that way normally.
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