Some electrical questions

[Dave 71]

Hi

I have a PV panel on my boat that seems to have stopped working, at least the solar control box thingy (a Fox 320) is no longer indicating that it is working - the manual helpfully tells me that if the LED next to the solar panel symbol is unlit it's 'nighttime'. The panel has a surface film which seems to have delaminated over winter. Would this have stopped it working?

This has led me to spot another potential issue, or at least something I'd like to check with someone with more electrical knowledge than me, peace of mind even if it is a daft question.

I went down to the boat on Saturday to do a few jobs and found that I had accidentally left the domestic power on and the fresh water pump turned on. This seemed to have discharged the domestic battery sufficiently to get a low charge warning, so I put shore power on. I don't normally leave the boat connected to SP as the solar has always seemed sufficient to keep charged batteries topped up. It did seem odd that the indicator light for the pump was enough to discharge the domestic batteries, a bank of three

Anyway, I got on with my other jobs and after an hour or so, noticed a humming noise in the saloon and after a bit of poking around traced it to the cooling fans of a Newmar Phase Three smart battery charger. It was very hot, to the point of making the surface temperature of the cabinets above and around it etc hot. The surface temp of the Phase Three was similar to that you'd get from a domestic radiator with the heating on full blast. The ammeter on the front was indicating that it was pulling 32Amps. I have never noticed the fans running or it getting hot before. Really, it just didn't feel right.

It's a horrible installation - nasty piece of wood butchery and the device sits behind the saloon seating, blocked by the cushions. To be far to whoever installed it, i can't see an obvious alternative location. When I left, I took the boat off SP, didn't feel comfortable leaving it on.

On Sunday I went back down, plugged it in again, but this time I removed the cushions and it didn't seem to get quite so hot, but was still pretty warm. The ammeter dropped back a little and was showing about 28Amps.

On reading up on the device later, I concluded that the 32A draw was correct as it was in full charge mode, and that what I saw on Sunday was the start of it backing off and beginning to drop charge down to trickle mode.

It was hot over the weekend, well over 30 degrees, so that would have contributed to it getting hot along with the high charging draw and rubbish location with poor air flow.

So, my conclusion is that the electrics are sound and the device is doing what it should do, but that maybe the cooling fans need replacement, air flow seemed poor even with the cushions removed. That I should see much lower amperage when the batteries are fully charged and that it shouldn't get hot in normal use, although I will remove the cushions when using SP, particularly if its hot weather and figure out a way of improving air flow over the unit. And that I should replace the PV panel.

Does this seem a reasonable conclusion? And yes, I am trying to track down a local marine sparks to talk to

 

[Boater Sam]

Stick on PV panels don't last long.
Make sure you have not got a battery with a shorted cell, it will pull the whole bank down, stink of eggs and poison you before it blows up.
If you battery charger has not got sufficient ventilation of course it will overheat! Its a daft place for it, fire risk.

 

[andsarkit]

You really need to get a multimeter and put some numbers on your investigation.
An indicator light drawing say 0.1A for 200 hrs will only take 20Ah so should be replaced by the charger in about an hour.
I suspect your PV panel has not been working well and the house batteries have gradually discharged.
You need to separate your house batteries (if more than one) and measure the voltage on each one. If below about 12.7V, put each one on charge and measure the voltage again after letting it rest for an hour or better still the next day. This will tell you if the batteries are still OK.
You could also check the standby current when the house batteries are turned on as there might be other devices drawing more current.
The PV panel probably needs replacement but you still need to check the health of the batteries or you many still have further problems.

 

[Alex_Blackwood]

Hi

I have a PV panel on my boat that seems to have stopped working, at least the solar control box thingy (a Fox 320) is no longer indicating that it is working - the manual helpfully tells me that if the LED next to the solar panel symbol is unlit it's 'nighttime'. The panel has a surface film which seems to have delaminated over winter. Would this have stopped it working?

This has led me to spot another potential issue, or at least something I'd like to check with someone with more electrical knowledge than me, peace of mind even if it is a daft question.

I went down to the boat on Saturday to do a few jobs and found that I had accidentally left the domestic power on and the fresh water pump turned on. This seemed to have discharged the domestic battery sufficiently to get a low charge warning, so I put shore power on. I don't normally leave the boat connected to SP as the solar has always seemed sufficient to keep charged batteries topped up. It did seem odd that the indicator light for the pump was enough to discharge the domestic batteries, a bank of three

Anyway, I got on with my other jobs and after an hour or so, noticed a humming noise in the saloon and after a bit of poking around traced it to the cooling fans of a Newmar Phase Three smart battery charger. It was very hot, to the point of making the surface temperature of the cabinets above and around it etc hot. The surface temp of the Phase Three was similar to that you'd get from a domestic radiator with the heating on full blast. The ammeter on the front was indicating that it was pulling 32Amps. I have never noticed the fans running or it getting hot before. Really, it just didn't feel right.

It's a horrible installation - nasty piece of wood butchery and the device sits behind the saloon seating, blocked by the cushions. To be far to whoever installed it, i can't see an obvious alternative location. When I left, I took the boat off SP, didn't feel comfortable leaving it on.

On Sunday I went back down, plugged it in again, but this time I removed the cushions and it didn't seem to get quite so hot, but was still pretty warm. The ammeter dropped back a little and was showing about 28Amps.

On reading up on the device later, I concluded that the 32A draw was correct as it was in full charge mode, and that what I saw on Sunday was the start of it backing off and beginning to drop charge down to trickle mode.

It was hot over the weekend, well over 30 degrees, so that would have contributed to it getting hot along with the high charging draw and rubbish location with poor air flow.

So, my conclusion is that the electrics are sound and the device is doing what it should do, but that maybe the cooling fans need replacement, air flow seemed poor even with the cushions removed. That I should see much lower amperage when the batteries are fully charged and that it shouldn't get hot in normal use, although I will remove the cushions when using SP, particularly if its hot weather and figure out a way of improving air flow over the unit. And that I should replace the PV panel.

Does this seem a reasonable conclusion? And yes, I am trying to track down a local marine sparks to talk toView attachment 158950View attachment 158945

Off the top of my head, without seeing your set up I would suggest a) Your PV panel is probably duff. You really need to check the voltage at the control box, preferably disconnected, cable ends and if there is a connection box at the panel, check there as well. Certainly looks suspect from the photo!
b) I think, again without seeing it, that your battery charger is probably OK, if the batteries are? I think that the charger is suffering from Location, ambient temperature and flat batteries. All these are contributing to the heat problem. If the current is dropping back with time then it would suggest the batteries (or battery) are charging. I would be patient and give it a bit of time to see how it goes. I would seriously consider relocation. The charger should be in a free air space to avoid overheating and in the worst case scenario fire risk.
P.S. Edit. You don't say which type of battery you have. However if by any chance it should happen to be a WET (Flooded) Lead Acid. make sure you check the electrolyte level!! In any case have a good look at the battery and make sure there are no signs of anything such as bulging etc. I have seen a so called "Maintenance free" battery dry out with nasty consequences when charged. Luckily caught before it was catastrophic!

 

[MontyMariner]

Your charger in what looks to be an unventilated area will get hot, especially if it's pushing out 32amps.
You don't say how long the battery bank was on charge for or what size and how old it is. The answers might suggest that a battery in the bank is knackered. You will need to check them on charge with a multimeter individually.
If your Solar reg is indicating that it's nighttime, then it's getting no I/P from the solar. A multimeter to measure the volts across the solar panel will confirm this. You don't give the age of the PV but if it's delaminating then it's probably quite old and probably due replacement.

 

[Boater Sam]

You will need to check them on charge with a multimeter individually.

Check them separated from one another an hour after charging as a bank, not when being charged.

 

[MontyMariner]

Check them separated from one another an hour after charging as a bank, not when being charged.

Should have said after charge.

 

[Dave 71]

Thanks. I will test the batteries properly with a multimeter although they are only a year old and since charging appear to be fine from the built in meter and gauge on the switch panel.

I've spoken to an electrician who's said much the same thing on batteries and suggested a couple of other options for the battery drain I experienced, although it seems it was a perfect storm of buggered PV not keeping the charge up, leaving the leccy on, hot weather and the charger running fill tilt in a poor location. He suggested that the failed PV itself may be an issue on drain if the diode is buggered.

I can probably improve the vent to the charger whilst looking for an alternative location and may just have to live with propping the cushion away from it when on SP. I suspect if batteries are charged it will sit there quietly delivering normal domestic current/battery trickle charge without overheating as it seems to have done for years since the previous owner installed it.

 

[pmagowan]

It is always a good idea to do a full review of your electrical system. A fire on board is much more likely and serious than the risk of orcas etc. There does tend to be a slippery slope of faults often described by the hole in the cheese model. Once there are a few holes in the cheese there is potential for them to line up!

eg is my charger appropriate for dealing with a fully discharged battery in its current location. 2 holes (discharged battery, charger specs). If they line up, potential fire.

 

[Alex_Blackwood]

Thanks. I will test the batteries properly with a multimeter although they are only a year old and since charging appear to be fine from the built in meter and gauge on the switch panel.

I've spoken to an electrician who's said much the same thing on batteries and suggested a couple of other options for the battery drain I experienced, although it seems it was a perfect storm of buggered PV not keeping the charge up, leaving the leccy on, hot weather and the charger running fill tilt in a poor location. He suggested that the failed PV itself may be an issue on drain if the diode is buggered.

I can probably improve the vent to the charger whilst looking for an alternative location and may just have to live with propping the cushion away from it when on SP. I suspect if batteries are charged it will sit there quietly delivering normal domestic current/battery trickle charge without overheating as it seems to have done for years since the previous owner installed it.

I strongly suggest that you relocate the charger. No ifs or buts. I would consider it a fire risk in the present location. Completely agree with pmagowan.
Anyway glad your batteries look OK, I suspected as much. as per PV unit