There goes battery charger number 3!

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stranded

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So, last Autumn our Mastervolt Mastercharger went bang - literally. This winter we had the 240v system completely rewired (by Berthon, so hopefully well). New Mass Combi Ultra went bang on first day we used it with generator. Generator and other wiring totally checked and is supposedly fine. Waiting for a warranty replacement for the Mass Combi Ultra I today bought a Ctek M300 as a stop-gap/emergency reserve. All started well plugged into shore power but after about an hour it went off. No fault lights or any other lights showing. I have checked the connections to the battery, changed the fuse in the plug and checked the 240v supply is ok.

There has to be something wrong on the battery side right? But what could it be that destroyed the 100amp Mastercharger, the 150 amp Mass Combi and the 25 amp Ctek, variously on shore power and generator?

Grateful for any ideas - this is getting expensive!
 
That is really strange. The Ctek chargers are very well protected and you can connect them the wrong way round or short them out and it will simply trigger protection circuits. I just can't see how anything "wrong" on the battery side would damage the Ctek.

Have you checked the mains for voltage and polarity? Had the fuse in the Ctek plug blown? Have you tried plugging the Ctek into a different mains outlet and resetting it (if that model has a reset button?) and connecting it to a battery which is not connected to anything else?

Richard
 
I don't know but only suggest avenues to investigate , have you got an inverter anyway in the circuitry and smart chargers are a bit temperamental with Gennys that are not pure sine wave output
 
Yeah, done all that. It's totally dead. Slight smell of burning from ventilation slits, though that could have been dust on first use I suppose. I wonder if it is linked to a problem I had starting a couple of weeks ago, where the starter circuit was pulling on the service circuit and causing something to blow temporarily - never found what as it would seemingly reset itself after a few minutes. I have though pointed all this out to Berthon and they are adamant there is nothing wrong with the engine circuit, even though I measured only c.2.6v across the engine master switch. Something mightily strange going on. If Berthon can't resolve tomorrow I am going to tell them I want to bring in an electrical guru I think. Any idea where I might find one of those!?
 
I have had problems with chargers packing up. Because of lack of space, I had to have it moved from under the aft bunk, where its noise caused a problem, to the rear of the cockpit locker. The last failure happened one month before a 2 yr guarantee expired, and we wondered if damp was the cause, since the charger had be switched off during the winter. For the last two years I have left the charger on and used drying granules nearby as it is isolated from the dehumidifier.
 
Thanks Rob. We're getting way beyond my electrical knowledge here, but just had a quick look at Wikipedia. The (Austrian) boat is fitted with two pin European AC sockets throughout, which wiki suggests aren't earthed. We use them with uk 3 pin adapters and uk spec appliances. Is this a problem in itself, and potentially relevant to this particular problem?

I don't think damp is a problem on ours John - main charger is in saloon and the Ctek had only been on board for an hour!
 
It might be worth checking out with an oscilloscope to check out the wave form in the AC side at least, then maybe the 12v side also to make sure there aren't any spikes or anything odd.

For that you'll need a guru as you originally suggested, but it does ound like there's something very wrong somewhere; some kind of cross contamination or something because it's very unusual to blow chargers like that.
Is there a wrongly connected inverter somewhere? Disconnect completely before trying anything else
 
ohmaggie said:
Yeah, done all that. It's totally dead. Slight smell of burning from ventilation slits, though that could have been dust on first use I suppose.
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What's your battery capacity? If you had a 150A charger, I guess you have a reasonably-sized battery bank. Might it be larger than the M300 is designed for?
 
Did it happen while on shore power or generator? Generators can be dodgy on any semi conductor based electrical items. Escpecially a switch mode charger. They don't produce very good quality electricity unfortunately. OK for power tools and such like but I wouldn't plug anything into one that is semi conductor based.
 
pvb said:
What's your battery capacity? If you had a 150A charger, I guess you have a reasonably-sized battery bank. Might it be larger than the M300 is designed for?
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No, I think it's ok - service bank is 400ah, M300 spec is up to 500ah. The 150ah was a bit overkill as it is the only 12v Mass Combi Ultra option and to allow for likely future expansion to 600 or 800ahs.
 
I would look at the input side - but where are you? Have any neighbours had similar issues? is the cable good - an intermittant connection could cause spikes but would also surely smell and have other indications. If the second one blew while on the generator, is there any input cable that is common to both mains and genny?
 
I had a similar problem. Turns out if the boat supply switch is set to generator and the generator is started it initially spikes around 400 volts blowing capacitors in the battery charger. The genny is a Fischer Panda.
 
Billjratt said:
I would look at the input side - but where are you? Have any neighbours had similar issues? is the cable good - an intermittant connection could cause spikes but would also surely smell and have other indications. If the second one blew while on the generator, is there any input cable that is common to both mains and genny?
Click to expand...

Shore power and generator have separate connections to the mass Combi, which acts as an automatic switch. The M300 was wired direct to shore power with a new shore power to 3 pin converter, bypassing all onboard wiring.
 
I just had a Victron charger die on me. I replaced it with a more powerful Sterling charger. It fondly cooked the batteries (OK they were real old) and its ammeter showed it at maximum output the whole time. I replaced the batteries, now all is rosy.
Conclusion: A big bank of old batteries can suck a lot of current and cook a battery charger over time.
 
The more I think about it the more I am convinced that the problem I had with the starter circuit a few weeks ago must be connected to this issue. Briefly, a fully charged starter battery, on its own switch, would not start the engine and when I tried the starter took down the whole domestic side for a few minutes - everything went off, then after varying times the domestics would come back on. I discovered that this could be accelerated if I switched off the autopilot breaker. I measured the voltage across the open engine start master switch and it measured only around 2.6v. I got the engine started by jumping past the switch. I have told all this to Berthon but they can't find anything and thought the MassCombi blowing was just a faulty unit. The M300 going rather goes against that and I remain convinced there must be an intermittent short between the engine and domestic circuits which is somehow causing this, though it is still hard to understand how the numerous protections built in to the Mastervolt and Ctek chargers didn't work. And why the domestic circuits seemingly blew then came back in spontaneously remains a mystery as it did eventually, even if I didn't fiddle with the autopilot switch. I fear this could be a long and expensive conundrum!
 
The only thing I can think off which might overwhelm the protection circuits on the chargers would be if mains voltage was somehow being applied to the 12V side of the charger.

This would seem to be impossible and you would have problems with fuses blowing or RCCD-things tripping all over the place.

Richard
 
Perhaps this is just the fates telling me to work out how my bloody boat works before going blue water, so maybe I should treat it as an opportunity to get intimate with the electrics and try to logic the thing out myself!
 
That seems a sensible way forward, painstaking though it may be it's the only way to resolve it properly.

No matter how many ideas we come up with on the forum, nothing can beat tracing the wires and following them through to see what is connected to what, how well and in what condition all the connections are. Only then will you really understand how it all works, and find the problem.
Keep us posted though, I for one would be interested to hear about how you get on and what you find. Good luck.
 
Mostly I agree with Trundlebug above - posts on here without circuit diagrams are just guesses and no basis for investigation.

I also agree with the OP. Its just too coincidental that he had starting problems before this issue happened. I found myself wondering if he has a dud battery to give that low voltage at the starter motor or alternatively a bad connection on say the earth circuit. Either way there is something wrong with the starter circuit.

So what I would do, even before bringing in a paid expert, is to systematically check through the wiring starting at the battery negative. Make sure each connection is clean and dry. Then do the same with the positive feed right through to the starter motor.. Isolate each battery and check its resting voltage.
 
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