Strange battery charger problem

HappyAfloat

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I have a sterling 50amp charger/power pack (not sure of model or age, it's in a yellow & white case). When operating the charger via shore power all is well, it charges and acts as a power pack. However, when it is powered by my 3.5KVA generator it's a different story. First the charger appears to be working, plenty of amps are pushed to the battery. But within 20-40 seconds the charge has reduced to zero and the charger fails to act as a power pack. Basically the service battery bank starts to discharge.

I know the generator is pushing out 220v and plenty of amps as it is easily driving the electric immersion heater.

The charger has 3 outputs and is connected to the following battery banks Service, Starter and generator Starter.

Any ideas ?
 

Talbot

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probably that the generator is sending the wrong shaped pulse of electricity for the charger. Some (the cheaper) generators do not have the capaboility of sending the exact shape so crerate a squared off wave form, whereas it sounds like the battery charger needs the proper signal.
 

Talbot

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[ QUOTE ]
Forgot to add that the generator is a dedicated marine installation, not a B&Q cheapy.

[/ QUOTE ]

Doesnt mean that it is a proper Inverter, rather than a generator
 

Billjratt

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does it work with the immerser off? The sterling is a switched mode power supply that takes a "slice" off each AC cycle, the area under the sine wave curve before cutoff being proportional to the power it requires to charge batteries etc. If the generator waveform is being distorted by a heavy load, (or is just not up to it) then the sterling will probably sense that and save it'self from possible damage, by chucking in the towel. as they say- if it works off the mains the genny is the prob.....
 

HappyAfloat

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Re: Strange battery charger problem - Update

After further testing, the problem seems to only occur if the generator start battery is connected to the charger when the generator and charger are running. The voltage on the generator start battery quickly climbed up to 15v (before I got nervous and shut the charger down) and the other banks are not charged. When disconnected all seems fine, which explains the battery switch between the charger and generator battery.

So it looks like the charger is getting confused about the state of the generator start battery. Possibly caused by the small charge (4 amps) that the generator supplies it's start battery ? I'll test this theory over the weekend by introducing a small charge via a solar panel on the service bank to see if the same results occur.
 
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