Renogy DC-DC 50A (Version 1) Major Scary Failure

[Farnorthsurfer]

It was an ordinary trip to the shops near home. The wife and I both noticed an electrical burning smell on the way to the shop. So much so that I had the bonnet up and was poking about under the seat looking for the source. Maybe a wire short I thought. Didn't find anything and everything seemed to be working.
On the way home in traffic was dismayed to see a curl of smoke rising from under the passenger seat and the smell was now very strong, emergency stopped in the nearest car park, a cemetery funnily enough! Turned it all off and disconnected the solar panel as I have a cut off for that on the B pillar.
Unbolted the passenger seat and had a good look around at the Lithium battery and system, no smoke now but for sure a smell from around the Renogy DC-DC unit.
Started up and drove home, wife in the back (although she wanted to walk home) not long after getting home and while looking at the unit it suddenly erupted in smoke and sparks, choking black smoke pouring out of the unit. It stopped after a minute as I stood by with my fire extinguisher and seemed confined to the Renogy unit.
Quickly disconnected the battery etc and then unbolted the unit and took it out of the van. Will follow up with a few photos of the unit.
I took it apart as I am guessing it is out of warranty and will contact Renogy later.
It hasn't tripped any of the protection fuses that I can see and as far as I know it was installed correctly. I also think it was one of the first units in the UK as it was brand new out when I bought it in 2019. I am assuming that as no other fuses were tripped (EDIT: the 60A protection fuse between unit and lithium battery is blown) its not a short in any of the input wiring and I haven't noticed and symptoms external to the unit.
The electrical system of my van and solar control is built around this unit. We are very glad it didn't go when we were onsite in Europe a few weeks ago or on the autobahn at 130kmh!!
I see from their website that Renogy sell an updated version and also now 'recommend' it is fitted with one of their special fuses.
Have to say that the unit has been great until this point, doing everything well as advertised, I also have the BT control for the app.
Would of been a nightmare if this had burst while the van was parked up or we were sleeping.

My question for discussion is, should I buy another one after our experience?
And if not is there a reliable alternative with DC-DC control to Lithium with temp cut off and solar control that will fit in the space?

 

[Farnorthsurfer]

Here are a few photos of the unit.
Internally there was a capacitor rolling around the case which I think must have dropped off when its surface mount melted.

Sure it’s not paper but it’s well burned up.

The other side of the main board.

 

[Cool Carlos]

Just installing one at the moment!

 

[Farnorthsurfer]

Just installing one at the moment!

I am not trying to put anyone off the Renogy, I have been very happy with its performance and have not heard of anyone else with this problem.
I may well end up buying another one.
Although it was quite dramatic I guess it did what it was supposed to and self extinguished, there is no heat damage to the van or surrounding wiring.
But for sure its a little unsettling and there is a debate about posting stuff like this, but for sure we learn from experience, ours and others which is kind of the point of the forum.

 

[t0mb0]

That sounds scary! Seems a bit odd either an internal or external fuse didn’t blow to protect it before it got to that point.

 

[Farnorthsurfer]

That sounds scary! Seems a bit odd either an internal or external fuse didn’t blow to protect it before it got to that point.

Yeah, on further investigation it has blown the DC-DC to lithium battery fuse. It’s a 60A fuse and this probably saved anymore damage.
The engine wasn’t running when it failed so it makes sense that the power to heat it up came from the leisure battery.
Will probably never find out what caused the short or failure in the Renogy unit.

 

[bobbybasic]

And if not is there a reliable alternative with DC-DC control to Lithium with temp cut off and solar control that will fit in the space?

This should fit in the space. Rock solid, Australian built and designed for very hot and dusty environments.

BCDC Classic Under Bonnet 50A DC Battery Charger

The REDARC BCDC1250D is a 12V, 50A In-vehicle DC to DC Battery Charger designed to keep your auxiliary battery charged when driving or with portable solar panels when parked.

www.redarcelectronics.com

https://cdn.intelligencebank.com/au/share/yE9N/KYvX/blJyo/original/BCDC+Brochure+NA

"What does the charger do if the temperature around it rises above its operating
temperature?
As the temperature of the BCDC Dual Input rises above a certain level the current capacity of the
output is decreased gradually in order protect both the battery and the BCDC Dual Input unit."

 

[Bigsidavies]

Yeah, on further investigation it has blown the DC-DC to lithium battery fuse. It’s a 60A fuse and this probably saved anymore damage.
The engine wasn’t running when it failed so it makes sense that the power to heat it up came from the leisure battery.
Will probably never find out what caused the short or failure in the Renogy unit.

Could the fault lie in the other direction then? Maybe a fault in the LiFePo BMS that has caused the dc-dc issue prior to the fuse blowing. And maybe that’s the reason for it ‘self-extinguishing’ - ie the fuse stopped the battery connection to the dc-dc and the excess current or whatever stopped.

 

[Farnorthsurfer]

Could the fault lie in the other direction then? Maybe a fault in the LiFePo BMS that has caused the dc-dc issue prior to the fuse blowing. And maybe that’s the reason for it ‘self-extinguishing’ - ie the fuse stopped the battery connection to the dc-dc and the excess current or whatever stopped.

The TN Power 100ah battery seems fine, voltage normal, not hot anything.
Suspect the fault lies in the Renogy somewhere but I am not discounting anything.

 

[Dellmassive]

Here are a few photos of the unit.View attachment 210434
Internally there was a capacitor rolling around the case which I think must have dropped off when its surface mount melted.
View attachment 210435
Sure it’s not paper but it’s well burned up.
View attachment 210436
The other side of the main board.

100% raise a ticket with Renogy, send them what happened, show them the pics.

It will be interesting to see what they come back with.

For reference, we know you was running a 100ah TN lithium.

But what was the rest of the setup?.

What type/size fuse was on the starter feed?

What type/size fuse was on the leisure feed?

What profile was the unit set to?

What Amp rate was the unit set too? (Full 50A?)

..

Was your solar connected to the unit?... how many Watts worth of panels? .... What was the VOC from the panels?

Glad you all ok, and the vans still good.



.

 

[Dellmassive]

I am not trying to put anyone off the Renogy, I have been very happy with its performance and have not heard of anyone else with this problem.
I may well end up buying another one.
Although it was quite dramatic I guess it did what it was supposed to and self extinguished, there is no heat damage to the van or surrounding wiring.
But for sure its a little unsettling and there is a debate about posting stuff like this, but for sure we learn from experience, ours and others which is kind of the point of the forum.

I've been running mine for couple of years.

Dc50S. Set to lithium profile, and set to 30A charge rate, no solar connected.

I also have a couple of Redarc units, both very good. ... And very small.

 

[CJW]

What Amp rate was the unit set too? (Full 50A?)

My first thought too, Lee. [Edit - missed that it’s Lithium]

 

[Farnorthsurfer]

100% raise a ticket with Renogy, send them what happened, show them the pics.

It will be interesting to see what they come back with.

For reference, we know you was running a 100ah TN lithium.

But what was the rest of the setup?.

What type/size fuse was on the starter feed? 70A

What type/size fuse was on the leisure feed? 60A

What profile was the unit set to? LITHIUM

What Amp rate was the unit set too? (Full 50A?) The unit had solar fitted so would only provide 25A max from the alternator unless the Solar is switched off.

..

Was your solar connected to the unit?... how many Watts worth of panels? .... What was the VOC from the panels? Photonic Universe 160w panel, I don’t recall the VOC off the top of my head but it’s quite high, another reason for choosing the Renogy in the first place.

Glad you all ok, and the vans still good.



.

Thanks @Dellmassive I will ping Renogy and see what they say but need the van back as have more trips planned. May well just buy another Renogy as it does everything I need it to do.
Hard to get high solar VOC input and low temp cut off all in the same unit.
For sure I think it was an internal failure of the unit, either a PCB joint or failed component.

 

[Buksie]

I’m using the Victron with inline fuses. No problems.

 

[manicism]

I am sure this has been covered elsewhere probably by @Dellmassive but can only find references to people having done it. Where in the app can you limit the charge current?

I am not seeing the option to limit current

Am i looking in the wrong place?

Wanting to limit the current on the dc-dc side to 30A max but allow the PV to be 50A ( I know when both sources available it limits to 25A max from each source).

 

[Farnorthsurfer]

I have never messed with the settings on the blown unit except to set the battery type using the pin switch on the unit.
My BT2 unit was only used with the old Renogy app to monitor solar charge etc. There were no details or information on changing the charge current beyond it being limited to 25/25 with Solar connected.

 

[Farnorthsurfer]

Quick update.
I have ordered a replacement Renogy 50A unit direct from Renogy and have not in fact queried Renogy about the failed unit as TBH I don't have the energy or time to either fill in their online forms or deal with the response which is very likely to be 'Sorry, the unit is out of warranty and we can't help' as the unit has been installed for over three years.
I don't think there is a problem with the rest of my system, its worked perfectly since I built it and I have no indications that other components are faulty.
Will update when I get it working again.

 

[CJW]

The

I am sure this has been covered elsewhere probably by @Dellmassive but can only find references to people having done it. Where in the app can you limit the charge current?

I am not seeing the option to limit current

Am i looking in the wrong place?

Wanting to limit the current on the dc-dc side to 30A max but allow the PV to be 50A ( I know when both sources available it limits to 25A max from each source).

I don’t have the BT module but do have the monitor. This is how it is set via the monitor. DellMassive is your man for the app - it’s was DM that pointed the charge limiter out to me in the first place, then I discovered the app would do it.

 

[Dellmassive]

I am sure this has been covered elsewhere probably by @Dellmassive but can only find references to people having done it. Where in the app can you limit the charge current?

I am not seeing the option to limit current

Am i looking in the wrong place?

Wanting to limit the current on the dc-dc side to 30A max but allow the PV to be 50A ( I know when both sources available it limits to 25A max from each source).

View attachment 210474

View attachment 210475

View attachment 210476

You need to download the Renogy "DC Home" APP.

The setting is in the settings/profile/menu.

That looks like the older APP?

 

[Dellmassive]

Quick update.
I have ordered a replacement Renogy 50A unit direct from Renogy and have not in fact queried Renogy about the failed unit as TBH I don't have the energy or time to either fill in their online forms or deal with the response which is very likely to be 'Sorry, the unit is out of warranty and we can't help' as the unit has been installed for over three years.
I don't think there is a problem with the rest of my system, its worked perfectly since I built it and I have no indications that other components are faulty.
Will update when I get it working again.

PM me with a pic of the.serial number etc, I'll raise a ticket for you.?

They need to be aware of what's happened. And may offer you a replacement unit.

It looks like the tracks have burnt, it's possible that something failed pulling less current than your supply fuse, causing a PCB burn. But then you say the supply fuse blew.?

So I would try to inspect every inch of the cables, and fuses and holders before fitting a new unit.. looks for burning or heat damage.

A 60A midi fuse needs 80,90,100A to actively melt or blow, ... So the supply cabling and fuse holder etc will have been subjected to very high current and heat.

Plus, also a consealed cable (run under carpet for example) has a much lower current rating due to heat build up that the same cable in free air.

Post pics of your install if you can.

Fuses, cable, battery connections etc etc.