Votronic 1212-30 B2B - *warning*

[activecampers]

I know a few here have these, so just a word of warning.
Seems to be a design fault that causes an internal fuse to melt and potentially burn (!)
If you look in the LHS of the unit look for any heat damage or melted case on the side.

Our unit stopped working - said charging - but no voltage being sent "out" to the LBs.

Problem appears to be that internally there is a 40A blade fuse in PCB holders, and it appears the connection between the fuse and the holder is poor (over time? by design?) - increased resistance, gets hot, melts, bang. Its a 30A unit, but 30A@ 14.4v output, which could be 37+A @ 11.8v input... So almost maximum fuse rating.

Board and components all look fine - it appears to be only the fuse connection to the holder causing the problem.

I will modify ours and to have good connections to an external fuse.

Of course, opening case DOES void 3y warrantee - but if you need a solution quicker than the turn around to/from Germany.....

 

[activecampers]

Below are 4 other owners with exactly the same issue, and if you read amazon reviews (where these images came from) many with the same problem.

So keep an eye - seems to be a design flaw and/or cheap fuse/holder (or under rated)

 

[ChrisL]

I'd be sending those photos to Votronic suggesting that they do an urgent recall before someones pride and joy goes up in flames.

 

[activecampers]

I'd be sending those photos to Votronic suggesting that they do an urgent recall before someones pride and joy goes up in flames.

Already done but no doubt as its opened there is no warrantee, and no doubt they are aware of the numerous amazon reviews (as many said they contacted Votronic).
TBH fuses melting like this is not uncommon in medium-->high current circuits - just most are visible in fuse boxes. My first van (pro build) did the same fuse melting about 7 years into ownership - must've been for same/similar reason.
Thinking about it overnight, I do think its likely to be corrosion or similar in the fuse holder-->fuse contact.

 

[BouncyBoatFolk]

Cheap Chinese fuses? Not a good look on a "premium" product!!
Mike.

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[activecampers]

Cheap Chinese fuses? Not a good look on a "premium" product!!
Mike.

Possibly, but (IMO) more likely a corroded connection between fuse and holder. Its not likely the current exceeded 40A - and indeed these type of fuses don't tend to instantly blow at 40.1A it can be a lot high A over a lot of time. The fact it was one leg hot/melt suggests high resistance in the leg.

In my internet trawling yesterday I could not find any PCB mount blad fuse holder rated for 40A.... Hmmm.

But you are right, blade fuses - should be branded only!!

(My external fuse mod will be to a midi-type which (AIUI) which will have better connections)

 

[BouncyBoatFolk]

Possibly, but (IMO) more likely a corroded connection between fuse and holder. Its not likely the current exceeded 40A - and indeed these type of fuses don't tend to instantly blow at 40.1A it can be a lot high A over a lot of time. The fact it was one leg hot/melt suggests high resistance in the leg.

In my internet trawling yesterday I could not find any PCB mount blad fuse holder rated for 40A.... Hmmm.

But you are right, blade fuses - should be branded only!!

(My external fuse mod will be to a midi-type which (AIUI) which will have better connections)

Selling it as a sealed unit that has the warranty voided by opening to rectify a fault induced by poor design is still not very good. A replaceable fuse should be accessible without major disassembly required. A customer's own external fuse should not be a requirement either. A reset button might be a more user friendly option.
Mike.

 

[activecampers]

Selling it as a sealed unit that has the warranty voided by opening to rectify a fault induced by poor design is still not very good. A replaceable fuse should be accessible without major disassembly required. A customer's own external fuse should not be a requirement either. A reset button might be a more user friendly option.
Mike.

Can't disagree with that.
The manual does state clearly "no user servicable parts". Ok then!

 

[activecampers]

FYI

If you have this issue, see the below email - TBH the support from them has (so far) been 10/10.

We deeply regret the inconvenience caused to you.

The damage observed here seems, as you already suspected, to be due to a resistance problem in the fuse socket.

Our current VCC 1212-30 no longer have the plugged fuses inside, but this is not due to the correction of a design error.

With the earlier device versions, an external insufficient ground connection between the leisure and the starter battery circuit triggered the input fuse under certain operating conditions.

The devices of the first two generations, to which yours also belongs, repeatedly tempted customers to open the devices and check the fuses due to the externally visible plugged fuses, which was not in our interest, hence that too Warranty seal above the screw. This has prompted us to reconsider the design. Now the customer no longer has the option of simply replacing the fuse without further measures. There is always a reason for a fuse to blow, which must be checked before replacing the fuse.

With this measure, we have already eliminated the cause that occurred in your and apparently also in other cases. It is a pity, however, that these customers apparently preferred a negative review to contacting our support. If you know one of these affected customers, please let them know that they can contact us at service@votronic.de regarding their problem.

 

[davidroxburgh]

Do you have any idea of when the first two generations of the product ceased?

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[activecampers]

Do you have any idea of when the first two generations of the product ceased?

No, sorry
If you look in the LHS vent, you will see either a board mounted fuse or a blade fuse in a holder. Its the blade fuse that has issues. In mine, the blade fuse was orange. The new one, the board fuse is a dark red.

 

[activecampers]

Final update

Considering I emailed over the weekend, but they never got back to me till Wednesday (yesterday).....

Considering my unit was out of warranty.....

Considering I'd taken it apart and modified (fixed) it......

They shipped a newer model to me yesterday, express, from Germany. Just arrived. I've installed and tested and the old unit is being collected in an hour.

Zero hassle. Zero cost to me.

W O W.

Thats customer service!!! And I'm glad, its a fantastic unit! 30A B2B, intelligent LiFePo4 charging, and back charges the engine if excess power (solar/hookup). Had been perfect, and I'm now confident in the replacement.

 

[Guigsy]

From the Votronic response, it says it's the result of insufficient ground connections between the batteries.

How would that cause the issue?

Is there evidence that they might be correct?

 

[activecampers]

From the Votronic response, it says it's the result of insufficient ground connections between the batteries.

How would that cause the issue?

Is there evidence that they might be correct?

Who knows? Its possible I guess.
I know mine are well connected, but only via a single terminal (as permitted in the manual) but who really knows. But the problem fuses are not on the new board so I'm happy.

 

[rwg]

From the Votronic response, it says it's the result of insufficient ground connections between the batteries.

How would that cause the issue?

Is there evidence that they might be correct?

Maybe... If you have installed with a single connection to the -ve of the B2B then the return flow from the -ve of the leisure battery to the -ve of the vehicle battery is via the van chassis or separate connection wire. If that has a high resistance then the voltages of the -ve terminals of the two batteries will differ, which may not be something the circuit is designed for.

When I installed mine I added an extra 16mm2 from my -ve busbar to chassis in addition to whatever link was in the existing wiring.

cheers,

Robin

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[rwg]

I found I kept coming back to thinking about how a bad ground connection might or might not impact the B2B operation, so in the end I sat down and worked it out properly from Ohm's law and a bit of basic electronics.

Assuming the B2B is trying to charge a lithium battery (14.4V) at 30A, it needs 432W of power (actually a bit more due to inefficiency, but forget that). That power comes from drawing a current on the alternator (say producing 14.2V). However, resistance between the alternator and the B2B (both +ve and -ve wires) means the B2B doesn't see 14.2V - there is some voltage drop in the cable, which means it needs more amps to get the 423W, and more amps means more voltage drop in the wires, and so on.

Anyway, I made a graph of the current being drawn by the B2B to supply 14.4V @ 30A output, depending on the total resistance of the wiring between the alternator and B2B

The resistance is along the bottom of the graph from zero ohms on the left to 0.12 ohms. The current is up the side.

You can see that with very small resistances the current drawn is only a bit over 30A, but as the total resistance climbs, so does the current, and with a resistance of more than about 0.115 ohms, the current goes sky high and you get to a point where the circuit just cannot support that power output.

So, I'm now pretty satisfied that a poor ground link between the two batteries (and equivalently between the B2B ground and the alternator ground) can cause excessive input current on a B2B. It would do it for all B2B devices unless they have a current limiting circuit on the input which would in turn cut down the output power.

However, you'd expect that excess current to blow the 40A internal fuse, not melt the fuse holder. The fact that the fuse holder melted at a current that the fuse itself survived indicates poor design, poor quality components or material degradation (corrosion, etc).

(Takes off geek cap...)

cheers,

Robin

 

[StillGoing]

I’ve had the Votronic B2B for 3 years without any problems. After reading this thread, I contacted Votronic and they confirmed I have one of the affected units. They are sending me a replacement free of charge.

From Votronic:
So far we have been able to confirm the situation you described regarding deformed input fuses in a few individual installation situations of the VCC 1212-30, in which there was obviously increased heat development due to the location and situation.

My colleague Eva asked you for the serial number, because from the third generation of devices the fuses are installed directly without a socket. Without a fuse socket, there is no additional physical heat source at this point.

According to the serial number, your device still has the said fuse socket, but this does not mean a problem if the ventilation at the installation site is taken into account.

 

[tonyidle]

I found I kept coming back to thinking about how a bad ground connection might or might not impact the B2B operation, so in the end I sat down and worked it out properly from Ohm's law and a bit of basic electronics.

Assuming the B2B is trying to charge a lithium battery (14.4V) at 30A, it needs 432W of power (actually a bit more due to inefficiency, but forget that). That power comes from drawing a current on the alternator (say producing 14.2V). However, resistance between the alternator and the B2B (both +ve and -ve wires) means the B2B doesn't see 14.2V - there is some voltage drop in the cable, which means it needs more amps to get the 423W, and more amps means more voltage drop in the wires, and so on.

Anyway, I made a graph of the current being drawn by the B2B to supply 14.4V @ 30A output, depending on the total resistance of the wiring between the alternator and B2B

View attachment 798413

The resistance is along the bottom of the graph from zero ohms on the left to 0.12 ohms. The current is up the side.

You can see that with very small resistances the current drawn is only a bit over 30A, but as the total resistance climbs, so does the current, and with a resistance of more than about 0.115 ohms, the current goes sky high and you get to a point where the circuit just cannot support that power output.

So, I'm now pretty satisfied that a poor ground link between the two batteries (and equivalently between the B2B ground and the alternator ground) can cause excessive input current on a B2B. It would do it for all B2B devices unless they have a current limiting circuit on the input which would in turn cut down the output power.

However, you'd expect that excess current to blow the 40A internal fuse, not melt the fuse holder. The fact that the fuse holder melted at a current that the fuse itself survived indicates poor design, poor quality components or material degradation (corrosion, etc).

(Takes off geek cap...)

cheers,

Robin

A simple fuse as used in the majority of automotive applications (and very many non-automotive applications) is rated at the current it will carry continuously. Close to instantaneous fuse failure only happens at twice the rated current. Any overload less than that will result in delayed failure to the extent that a 25% overload (in this case say 50A) may well take hours to rupture the fuse. During which time it will get hot.

 

[activecampers]

A simple fuse as used in the majority of automotive applications (and very many non-automotive applications) is rated at the current it will carry continuously. Close to instantaneous fuse failure only happens at twice the rated current. Any overload less than that will result in delayed failure to the extent that a 25% overload (in this case say 50A) may well take hours to rupture the fuse. During which time it will get hot.

True

But don't think this issue was caused by any overload - moreso increased resistance in the fuse connector (that probably wasnt rated at 40A anyway - at least I was unable to find any connector rated at 40A!). And proabably over time with expansion/heat changes and corossion the resistance got higher and higher until the heat cause the issue.

The replacement unit working perfectly.

 

[Bertilak]

With one of these units, fitted c20 months ago, I'm concerned by this. Can anyone advise where the serial number is located, please?
I can't see it on any of the three faces I can see (front bottom & right), but knowing may help with how much un-wiring I need to do.

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[StillGoing]

With one of these units, fitted c20 months ago, I'm concerned by this. Can anyone advise where the serial number is located, please?
I can't see it on any of the three faces I can see (front bottom & right), but knowing may help with how much un-wiring I need to do.

It’s printed on the top side on mine - opposite side to where the wires go in.

 

[Jez1966]

On the "positive" side, it should only possible catch fire while in use/your in the van.
So install several fire extinguishers and install with Velcro for quick removal.
An option would be to reduce the fuse rating if lower is sufficient for your needs.

 

[MisterB]

Just been looking at buying a 40A (or bigger) voltronic B2B, if I do I will ensure my buyers message includes reference to the issue, thanks for highlighting it!

 

[Lenny HB]

At least they have responded and customer service appears to be good.

Although you can get standard blade fusholders and blade fuses rated at 40 amp I really don't think 40 amps through a standard blade fuse that relies on a poor spring connection is a good idea.

I've just had a similar problem at the start of my current trip. My Goldschmitt air suspension packed up. The 40 amp blade fuse feeding the compressor both fuse holder and fuse had melted. The fuse is in a waterproof fuse holder under the bonnet, I suspect vibration over time had caused a poor connection and it had been arcing. The compressor draws 30 amps and only runs when the tank needs topping up so running time is not much overall, it's been installed for 5 years.
Bodged it until we get home, managed to force a 30 amp fuse in and held with a cable tie.

 

[Gerry77]

I never thought I would ever see that word “ bodged” in a post by you Lenny!
Needs must eh!
Hope it lasts till you get back.

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[Bertilak]

It’s printed on the top side on mine - opposite side to where the wires go in.

View attachment 813503

Thanks: I can get to that without having to unwire it!

 

[activecampers]

With one of these units, fitted c20 months ago, I'm concerned by this. Can anyone advise where the serial number is located, please?
I can't see it on any of the three faces I can see (front bottom & right), but knowing may help with how much un-wiring I need to do.

Look in the LHs
If you can see a blade fuse in holder like the pics it's old version.

 

[activecampers]

With one of these units, fitted c20 months ago, I'm concerned by this. Can anyone advise where the serial number is located, please?
I can't see it on any of the three faces I can see (front bottom & right), but knowing may help with how much un-wiring I need to do.

It should have space for airflow around and not boxed in anyway...

 

[activecampers]

On the "positive" side, it should only possible catch fire while in use/your in the van.
So install several fire extinguishers and install with Velcro for quick removal.
An option would be to reduce the fuse rating if lower is sufficient for your needs.

That would not work. It would constantly blow if lower. You can't use a fuse as a current limiter (well, you could, but single use!)

 

[activecampers]

Just been looking at buying a 40A (or bigger) voltronic B2B, if I do I will ensure my buyers message includes reference to the issue, thanks for highlighting it!

It's only the 30a version affected. The bigger versions will not have blade fuses

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