Do we need a new battery? ☹️

[JTQ]

Adding to the controller debate:
Whilst it may be stating the obvious to some, with our use of solar systems the real challenge is quite different to typical solar applications.
Our challenge is not getting the highest yield from the system but more the highest yield under challenging light conditions.
I suggest most of us can get all our batteries can hold on bright summer days? We have an 85Watt freestanding panel and during the summer on a good day fully recharge our battery back up by 10:00 to 10;30 hrs.
Where we struggle is getting the most, or even enough out of overcast or low sun angle days. The more so for others with panels installed flat on roof and so not "aimed".

It is in this specific area we really need to focus, and look to exploit what controllers and panels can offer.
Here matching panels with high maximum power point voltages, to MPPT controllers that by nature can work over a wide input voltage are particularly attractive.
This high maximum power point voltage characteristic of some panels, means there is a decent driving voltage at lower light levels well off the maximum. Whereas a more tradition panel with something like 17 to 20 volts maximum power point voltage, is not going to have much voltage under low light conditions to drive any real power into the battery. And that is what we see in real life with our normal kit.

If I was buying again today the first move would be to buy something like a 36 volt maximum power point panel, and then couple this to a high spec MPPT controller.
I don't expect that to help me much if it fully recharges my battery an hour earlier in summer, but I would expect it to make yield on low light days quite a bit higher, my real-life goal for caravanning.

Just an aspect to throw into the deliberations.

 

[Jcloughie]

Adding to the controller debate:
Whilst it may be stating the obvious to some, with our use of solar systems the real challenge is quite different to typical solar applications.
Our challenge is not getting the highest yield from the system but more the highest yield under challenging light conditions.
I suggest most of us can get all our batteries can hold on bright summer days? We have an 85Watt freestanding panel and during the summer on a good day fully recharge our battery back up by 10:00 to 10;30 hrs.
Where we struggle is getting the most, or even enough out of overcast or low sun angle days. The more so for others with panels installed flat on roof and so not "aimed".

It is in this specific area we really need to focus, and look to exploit what controllers and panels can offer.
Here matching panels with high maximum power point voltages, to MPPT controllers that by nature can work over a wide input voltage are particularly attractive.
This high maximum power point voltage characteristic of some panels, means there is a decent driving voltage at lower light levels well off the maximum. Whereas a more tradition panel with something like 17 to 20 volts maximum power point voltage, is not going to have much voltage under low light conditions to drive any real power into the battery. And that is what we see in real life with our normal kit.

If I was buying again today the first move would be to buy something like a 36 volt maximum power point panel, and then couple this to a high spec MPPT controller.
I don't expect that to help me much if it fully recharges my battery an hour earlier in summer, but I would expect it to make yield on low light days quite a bit higher, my real-life goal for caravanning.

Just an aspect to throw into the deliberations.

I remember researching these points 6 years ago when I put mine in. And it was clear that the controller had to suit the output voltage of the panel, or panels. The expected light conditions, the type of panel, etc.. It is certainly not completely clear to an amateur.


I will keep looking for now, though I am getting there. So far found out that it is not about the cost. I could pay a lot of money for one which would work fine on a larger system.

Onwards and upwards though.

John

 

[WayneS]

Hi John,
No words of advice or suggestions from someone like me who lacks knowledge and understanding of this matter. Whilst I'm sure a very rare event, nonetheless a very scary one - pleased you weren't in the caravan when it happened!
I'm sure not likely to reoccur but hope you can firmly nail down the most likely cause.
Best of luck, Wayne

 

[Raywood]

Looks like there was no regulator fitted to the panel, or if there was one, it failed. Frankly I would not use the battery again and just get another. The wiring looks damaged and should be repaired. Given the box looks to have had it as well, then the cost may justify an insurance claim.
I would have an engineer look at it as the work needs to be done correctly.

 

[JTQ]

Looks like there was no regulator fitted to the panel,

John had mentioned a controller several times, I think we can take it had one, so it faulting is a possibility;

But I also wonder if the solar controller malfunctioned.

Just been looking for a replacement controller

I will not bother testing the old controller. I will just bin it

 

[Jcloughie]

Looks like there was no regulator fitted to the panel, or if there was one, it failed. Frankly I would not use the battery again and just get another. The wiring looks damaged and should be repaired. Given the box looks to have had it as well, then the cost may justify an insurance claim.
I would have an engineer look at it as the work needs to be done correctly.

When the storage site owner phoned me to say the battery had exploded I imagined half the side of the van to have gone. As it happens, the damage is confined to the battery box. Amazingly, a new box is only £120. Delivered. Which I think is great for a caravan spare. It comes with a new mains inlet, a tray, a strap, a door and a new lock.

Fitting should be easy, so a long way off an insurance claim. The battery would not have been covered anyway.

John

 

[Jcloughie]

As an aside to this topic. As we know, batteries can gas off in certain circumstance. So battery boxes should be sealed from the inside of the van. And quite rightly. But the door seems a close fit and has a seal.

Do others think a vent in the door would be wise?

John

 

[otherclive]

As an aside to this topic. As we know, batteries can gas off in certain circumstance. So battery boxes should be sealed from the inside of the van. And quite rightly. But the door seems a close fit and has a seal.

Do others think a vent in the door would be wise?

John

The locker door is already designed to vent hydrogen emitted under certain charge conditions. But it’s not designed to relieve a extremely rapid over pressure such as your system experienced.

 

[Jcloughie]

The locker door is already designed to vent hydrogen emitted under certain charge conditions. But it’s not designed to relieve a extremely rapid over pressure such as your system experienced.

I was talking in general, not about my specific case. Looking at the damage more closely. I feel sure the explosion came from within the battery. But I can’t locate the epicentre.

It is nice to know that they are designed to ventilate. To me they look just the same as a wet locker door. Except for the cable inlet notch. I will examine carefully when the new one arrives.

I remember buying a new van in 1990. This is the battery box that was supplied to go under a bunk!


Things have moved on.

John

 

[otherclive]

I was talking in general, not about my specific case. Looking at the damage more closely. I feel sure the explosion came from within the battery. But I can’t locate the epicentre.

It is nice to know that they are designed to ventilate. To me they look just the same as a wet locker door. Except for the cable inlet notch. I will examine carefully when the new one arrives.

I remember buying a new van in 1990. This is the battery box that was supplied to go under a bunk!

View attachment 2456
Things have moved on.

John

Sorry but your post seemed to be seeking views on whether a vent is required but read as if you were discussing your recent experience.
To control whatever affected your caravan would probably require a rupture diaphragm. Unless it was a very rapid build up of hydrogen that was then ignited, but as you said and the pictures show there’s no evidence of a ignited explosive event. If you look at the size of the battery vents then they are only sized to vent the designed quantity of hydrogen. That gas dissipates very quickly so under normal conditions the existing designs are perfectly adequate. But I agree the prime cause does look as if it was the battery failing under an over pressure.

 

[JTQ]

A hydrogen fire will just leave things a bit damp, or heat affected. Here a perfect gas mix ratio for H2O.

I suspect any combustion explosion would really have involved so small amount of "product" it is unlikely to leave much if any visual heat damage; just make a big bang in a very small box, the battery's gas void space.

 

[Jcloughie]

Sorry but your post seemed to be seeking views on whether a vent is required but read as if you were discussing your recent experience.
To control whatever affected your caravan would probably require a rupture diaphragm. Unless it was a very rapid build up of hydrogen that was then ignited, but as you said and the pictures show there’s no evidence of a ignited explosive event. If you look at the size of the battery vents then they are only sized to vent the designed quantity of hydrogen. That gas dissipates very quickly so under normal conditions the existing designs are perfectly adequate. But I agree the prime cause does look as if it was the battery failing under an over pressure.

I did start the post with 'as an aside' to try to make it a separate question.

I understand where the vents are on the battery. The question I was putting forward is:- should the box be ventilated to the atmosphere? I cant see the 'over pressure' scenario as the battery vent was clear.

A hydrogen fire will just leave things a bit damp, or heat affected. Here a perfect gas mix ratio for H2O.

I suspect any combustion explosion would really have involved so small amount of "product" it is unlikely to leave much if any visual heat damage; just make a big bang in a very small box, the battery's gas void space.

I strongly suspect that that is what happened here but I am baffled as to what might have caused the ignition. The only load on the battery could have been the alarm.

My brother was working on the construction of a steel structure in a factory, this was tack welded only to later be reassembled on site. Someone had left propane on from the previous shift. this had settled under the grid that the structure was being built on.

My brother light a burner. this caused an explosion. Although he was right in the middle of this, the actual explosion itself did not hurt him. However, it shook the structure and an 8' x 4' sheet of half in steel fell and just grazed his back slightly.

John

 

[otherclive]

I did start the post with 'as an aside' to try to make it a separate question.

I understand where the vents are on the battery. The question I was putting forward is:- should the box be ventilated to the atmosphere? I cant see the 'over pressure' scenario as the battery vent was clear.



I strongly suspect that that is what happened here but I am baffled as to what might have caused the ignition. The only load on the battery could have been the alarm.

My brother was working on the construction of a steel structure in a factory, this was tack welded only to later be reassembled on site. Someone had left propane on from the previous shift. this had settled under the grid that the structure was being built on.

My brother light a burner. this caused an explosion. Although he was right in the middle of this, the actual explosion itself did not hurt him. However, it shook the structure and an 8' x 4' sheet of half in steel fell and just grazed his back slightly.

John

If you can’t see an , over pressure scenario how is the battery condition explained. What purpose would the vents fulfill. If the build up is rapid they would have to be large. If not rapid but an explosive mixture ensues the normal vent arrangement should be sufficient. Unless for any reason that was restricted and didn’t do it’s job.

 

[Jcloughie]

If you can’t see an , over pressure scenario how is the battery condition explained. What purpose would the vents fulfill. If the build up is rapid they would have to be large. If not rapid but an explosive mixture ensues the normal vent arrangement should be sufficient. Unless for any reason that was restricted and didn’t do it’s job.

I 100% agree that more ventilation in the box would have made zero difference in my situation at the time of the explosion. But that was not my point or the question I put. It is the 'normal ventilation' that the box, (not the battery) has. You say its sufficient. You may be correct. But where is it? It certainly is not obvious. The compartment door is sealed against the weather from the outside.

All advice given, from whatever source, is to ventilate whenever charging a battery. Our battery room, when I was at work, had a permanently open window plus an extractor fan which had to be on when charging was in progress. Yet a caravan battery is contained in a reasonably well sealed box.

As I said, I could well have missed some hidden vent in the door casing, I will inspect that when the new one arrives.

John

 

[otherclive]

I 100% agree that more ventilation in the box would have made zero difference in my situation at the time of the explosion. But that was not my point or the question I put. It is the 'normal ventilation' that the box, (not the battery) has. You say its sufficient. You may be correct. But where is it? It certainly is not obvious. The compartment door is sealed against the weather from the outside.

All advice given, from whatever source, is to ventilate whenever charging a battery. Our battery room, when I was at work, had a permanently open window plus an extractor fan which had to be on when charging was in progress. Yet a caravan battery is contained in a reasonably well sealed box.

As I said, I could well have missed some hidden vent in the door casing, I will inspect that when the new one arrives.

John

I’ve spent time in sealed compartments with large battery banks and no external ventilation. Hydrogen had to be addressed as well as carbon monoxide in catalytic “burners”.

Be interested in your findings when the new battery box arrives.

 

[Hutch]

It looks as though the only gap/ vent is where the EHU cable comes in.

 

[JTQ]

View attachment 2457

It looks as though the only gap/ vent is where the EHU cable comes in.

But, the EHU subsection should be "sealed" from the battery housing section.
You can't have a plug and socket in a battery compartment; note the sealed divider.

The EHU section is also often used for mover switches and solar inputs all things we must not do in battery compartments, these days.

 

[Jcloughie]

I’ve spent time in sealed compartments with large battery banks and no external ventilation. Hydrogen had to be addressed as well as carbon monoxide in catalytic “burners”.

Be interested in your findings when the new battery box arrives.

View attachment 2457

It looks as though the only gap/ vent is where the EHU cable comes in.

Thats what I thought Hutch. But….

I have the old broken door in the garage. I just looked at it, around the inside edge which comes just inside the door seal there is a narrow gap. This leads to two small holes on the outside of the seal at the bottom of the door. So excess moisture could drain out, also it would provide ventilation, but not very much. They are not obvious at first. It is no doubt sufficient to disperse excess gasses in normal conditions. But perhaps not if there is over-gassing which I suspect is what happened in my case.

John

 

[Hutch]

But, the EHU subsection should be "sealed" from the battery housing section.
You can't have a plug and socket in a battery compartment; note the sealed divider.

The EHU section is also often used for mover switches and solar inputs all things we must not do in battery compartments, these days.

I failed to notice that, 🤔

 

[Jcloughie]

Update.

Went to fix the new battery box in Yesterday. I could not finish the job as I forgot the mastic gun and needed a bigger drill bit for the mover leads grommets.

I found that the harness area behind the box was splattered with acid. I tried the new box in poition and it fits well. I also changed the controller. The new one was given to me by my son as he wanted a Bluetooth enabled one. I am sure it’s a PV~Logic one PWM type. As professionally fitted to his new camper-van. But it’s badged differently.

Today I tackled they acid. It’s difficult as it is over a large bundle of wires and I can’t get to all areas. So I sprayed everything with a mixture of vinegar and lemon juice, with bi carb on selected areas. But it’s had time to do damage if it was going to. Hopefully it‘s just discolouration and the treatment will help to neutralise.

These are the finished pictures. The new box panel is a different shade of white but I don’t think it looks too bad.

I have tested it all and it works fine. To be safe I have not left the solar panels switched on.

Note the right angled bends on the battery terminals to make them easier to attach and detach.

Also note the discolouration to the support batten under the box Hopefully it will dry out, I have left the seat open to help.

Also the relocation of the TV in connector.








John

PS, I left the battery strap at home!

 

[Jcloughie]

My brother has the same van as we do but a few years newer. He just called me to say his battery had failed! What a coincidence. At least it was not a dramatic at mine.

But he showed me a picture of the Sargent display. And it looked odd to me. I told him to disconnect the mains, and to disconnect the battery for 30 secs. All is now fine and working properly.

Can't beat a reboot every so often.


He goes away tomorrow and that saved him having to go to Halfords last minute shopping.

My failing battery cost me about £250 plus a load of work. But at least I saved my big brother a few bob.


John

 

[Buckman]

Have you set the controller to AGM as many people leave it set for lead acid battery? There is a difference.

 

[Jcloughie]

Have you set the controller to AGM as many people leave it set for lead acid battery? There is a difference.

The new controller, like the old one, does not have profiles for different battery technologies. I am still considering getting one that does.


John

 

[Jcloughie]

Update

I am more than happy with the work I did on repairing the battery box and installing the new controller as per the pictures in post #46. But I have since discovered more damage caused by the explosion. I am now sorry I did not make an insurance claim.

First: The van was collected from storage to prepare for a break. The new battery was totally flat. My Ctek type charger would not even recognise its presence as it only had 2.5 volts. While in storage I deliberately left the solar panels off as I do not yet trust the system to be left alone. I turned off the 12 volt isolation switch as normal when leaving the van. But this switch failed to turn off. Perhaps due to the explosion.

I managed to get the battery charging by putting a small 12 volt battery in parallel for a short while. When I disconnected the small battery the charger kept going. I got the battery to 13.5 volts but the charger does not recognise that it is full so I think the battery has some damage.

I replaced the battery and all systems worked.

Second: The mover refuses to work. The control panel was not far from the explosion but looked fine. It gave a fault code which is not listed. But does allow the remote to be programmed to it. Truma were very nice on the phone but just said I would have to send it back. They also said that at 6 years old it was doing well! They also said it might have 'locked me out' as they do that sometimes. A reset is £40plus vat pus postage. for a reset on their own product.

That's a problem I still need to sort £400 plus for a new unit.

Third: (it goes on). We got onto site in Devizes now having to revert to my reversing skills. Set the van up, turned on the water to make a new flood over the electrics. The Whale water inlet incorporates an external shower connection. (never used). For this there is a ridged connection pipe at the back. This is what was damaged in the explosion. After some contortionist type of plumbing I managed to by-pass that connecting pipe.

I turned the water back on and more flooding. It was hard to see at first but the pressure switch had split open.

I had a trip to Wiltshire caravans for a new one, but bought an internal pump instead. That's all fitted and working now but it was not the sort of short break I was looking forward to.

Just the mover to sort out now. I see there is someone on eBay who is set up to do repairs, I may go down that route.

John

 

[Buckman]

Wow that is a real list of issues all stemming from the battery explosion. Can't you put in a claim for the rest of the damage i.e. mover as PCB may now be shot?