Sterling charger question

[Doodlebug]

Hi everyone,

 

We have just bought a sterling pro charge u 40amps and are running it off our yamaha 1000kw pure sine genny.

 

Its working perfectly but I have had two occasions that it has done something strange, i'm sure its usual but it would be good to know what its doing.

 

The charger had been on for around 30 mins, and was charging at around 30 amps, the genny running fine and it suddenly went down to around 10v at 1 amp, two seconds later up to ten, then 1, 10, 1... then the genny decided it couldn't cope and cut the power.

 

The genny revs went right up with each time the digit changed.

 

What on earth was the charger trying to do. It was in absorption at the time, and on restarting the generator it all goes back to normal.

 

The thing that confuses me is if it says 10v at 1/10 amps how could it have drawn too much power from the genny.

 

I hope its not a problem with the charger.

 

Any thoughts? Cheers

 

Doodlebug

[by'eck]

Genny throwing the charger into confusion? Charger throwing the genny into confusion?

 

Can you check charger out with shore power to confirm its not that at fault?

[Paul's Nulife4-2]

Hi ya Doodlebug,

How big is your genny ! ? .if its that big,I should think that should cope no trouble at all @ low revs. Maybe its an internal P,C,B or switching fault. Does it happen while say Boiling a kettle,or 2.or immersion heater or any other HIGH draw appliance.

Edited October 8, 2013 by Paul's Nulife4-2

[Doodlebug]

No real way to test it out really. Even if we paid for a night with shore power it wont help, because it seems intermitted. Its happened twice in the five or six times we have had it charging so far.

 

Genny is 1kw and should cope fine, and the fact its giving out 15v at 40amps no trouble, and then when it goes funny it cant supply the 10v at a couple of amps makes it more confusing

 

It obviously has a two year warranty so I can sit tight, but would be easier, if it is faulty to take it back to the marina which we are moored near.

 

So theres no mode between absorption and float which uses an on off charge approach. The only thing I could think of was some sort of desulpherisation phase.

 

I suppose I could ring sterling and see if I can find out.

 

Cheers

[Paul's Nulife4-2]

Aaahh 1kw (not 1000kw,I did wonder).

We'll my understanding is that,even if its rated @ say 1kw,it will only deliver that for a short time,before dropping down to its mor comfortable output,which is probably no more than 700w ish.so depending on what you've got plugged in,it might just be struggling.especially as its new,its arguable that high loads shouldn't be run on it,just yet.

But its only my guess,

Hope you get it sorted anyway.

[Doodlebug]

Even that doesn't follow, it runs fine at its full rating when charging flat batteries so why would it falter halfway through. I need to wait for it to happen again so I can see what lights come on.

 

Sorry I meant 1000w, its too late and i'm tired!

 

I'll let you know what I find.

 

Thanks

[by'eck]

Don't take too much notice of the 10 volt indication. It couldn't possibly be that in reality and was a clear sign that the charger was not behaving correctly for whatever reason. A phone call or email to Sterling may be revealing.

[jonathanA]

I have had problems with smaller generators when running equipment that switches from a small load to big load and back again l like PA amps, which draw naff all until someone shouts down the microphone ! a lot of suitcase generators don't like that sort of thing and I've even had to resort to plugging in a 100w bulb to keep a minimum load on them - but it doesn't always work. might be worth trying something similar find something thats 100-200W and leave that as a constant load and see if you have the same problems.

[Doodlebug]

Just an update on what the problem was, we found out and its sorted.

 

We hadn't run the charger for a few days and our batteries were pretty much flat. I put on the genny and the charger was sitting at 40 amps for a while. Then all of a sudden it went down to 0 amps.

 

I had a fiddle around with restarting the generator etc, and then went checking connections. The inline fuse had totally melted. The casing, wire, everything, and could easily have set alight to some fabric that was nearby. The man in the marina I bought it from gave me a 40a fuse, and I never thought to check what he had given me.

 

I assume since it had been sitting at 40a constantly it had overheated but not blown.

 

Anyway, when the fuse disconnected (as it heated up), and then reconnected, it was that which caused the problems listed in the OP.

 

So three lessons learn't:

 

1) Double check what your being sold.

2) Always use a fuse much bigger than the charger output.

3) If the charger is disconnected and reconnected to the batteries, it gets confused.

 

Thanks for the help given, i'm glad its sorted (and we didn't have a fire!)

[George94]

So often with electrical problems, it's not the equipment itself that's at fault, but the wiring or fuses. These should be the first things to check.

 

Also usually the cheapest to fix, thank goodness!

[by'eck]

Just an update on what the problem was, we found out and its sorted.

 

We hadn't run the charger for a few days and our batteries were pretty much flat. I put on the genny and the charger was sitting at 40 amps for a while. Then all of a sudden it went down to 0 amps.

 

I had a fiddle around with restarting the generator etc, and then went checking connections. The inline fuse had totally melted. The casing, wire, everything, and could easily have set alight to some fabric that was nearby. The man in the marina I bought it from gave me a 40a fuse, and I never thought to check what he had given me.

 

I assume since it had been sitting at 40a constantly it had overheated but not blown.

 

Anyway, when the fuse disconnected (as it heated up), and then reconnected, it was that which caused the problems listed in the OP.

 

So three lessons learn't:

 

1) Double check what your being sold.

2) Always use a fuse much bigger than the charger output.

3) If the charger is disconnected and reconnected to the batteries, it gets confused.

 

Thanks for the help given, i'm glad its sorted (and we didn't have a fire!)

 

Unusual hard to find fault until the fuse/fuseholder started to melt. Sterling recommend a fuse 20% larger than the max output current of the charger in the positive feed of each of the three outputs.

 

Although it used to be specific requirement with earlier models its still good practice with your model to link any unused output to one that has a battery load.

[smileypete]

Yeah would be interesting to know what type fuse and fuseholder it was.

 

cheers, Pete.

~smpt~