Caravan solar charging and gauges enquiry.

[wiley coyote]

I've just bought a 2nd hand caravan, which has a large variety of solar equipment and charging items of which I know nothing about, so I'm hoping someone can give me a bit of an idea what it all does.

 

[Moneybox]

Solar panels are much alike although I've found the better brand name panels perform the best. I have a Kyocera and some GE panels that out perform the cheap Chinese ones however they all seem to do the job.

The Redarc modules are very good quality and it might be worth getting your hands on operating manuals for these.

I don't know much about the other items although I did have a little blue solar controller similar to yours that failed early in life and destroyed a battery that was about ten times its value. I would never buy another like it.

 

[bicter]

Hi Wiley,
I'll try and help with general comments.
The solar panel and PWM regulator are low end equipment and probably wont meet spec but will provide some power to your batteries. A solarpanel that doesn't provide short circuit current in its specs is always suspect.

The Manson SPA-8330 is a 12V power supply capable of providing 33 Amps from 240V - probably being used to run the caravans 12v system when 240V is available. However, as it is adjustable up to 15V the previous owner may have been using it as a battery charger when mains is available but at 33Amps would, dependent on battery bank size, probably cook AGM batteries sooner than rather than later. https://www.manson.com.hk/product/spa-8330/

The Traxide SC40-12 is I think, similar to a Voltage Sensitive relay (VSR) but you would need to confirm that. https://traxide.com.au/

The Redarc BCDC1220 - The REDARC BCDC1220 is a 12 Volt 20 Amp In-vehicle DC to DC battery charger designed to keep your battery charged whilst driving. Featuring multi stage battery charging, the system charges your auxiliary battery from your vehicle to a proven 100%. https://www.redarc.com.au/smart-start-bcdc

If you ever intend to go with Lithium batteries all of the above equipment should be upgraded

If you can provide the following info, may be ablke to assist further:
1. Size of all batterie/s in Amp Hours (AH) and chemistry
2. Total current draw with everything operating
3. Type of fridge and P/No (ie 3 way or compressor type and capacity)
4. Part number of the panel meter shpwn in last pic.

Good luck

 

[wiley coyote]

Hi bicter and Moneybox. Thanks for all the info. bicter I've got some of the other items you asked me to provide, for you to assist me further. The battery is a Century 102 A.H. wet cell. Normal caravan fridge. 3 way. I couldn't get a part no. of the meter in my last photo. Total current draw with every thing working, unknown. This label is on the solar panels meter. 12/24 volts. Rated current 30AH. Max PV voltage 50V. Max PV input (power) 390W (12V) 780W (24V). There's a black box behind each folding solar panel The one in this photo looks like it's overheated at some time, as its a bit wrinkled.

 

[wiley coyote]

The fried black box in the last photo is a PV-807 1000V 4mm2 . Hope this all helps. wiley.

 

[Moneybox]

Hi bicter and Moneybox. Thanks for all the info. bicter I've got some of the other items you asked me to provide, for you to assist me further. The battery is a Century 102 A.H. wet cell. Normal caravan fridge. 3 way. I couldn't get a part no. of the meter in my last photo. Total current draw with every thing working, unknown. View attachment 7022This label is on the solar panels meter. 12/24 volts. Rated current 30AH. Max PV voltage 50V. Max PV input (power) 390W (12V) 780W (24V). There's a black box behind each folding solar panel The one in this photo looks like it's overheated at some time, as its a bit wrinkled. View attachment 7028

That black box is just covering the cable connection I think. Open it and check that the terminal is clean and tight. It shouldn't run hot so there must be a lose or dirty connection.

 

[user 22230]

I'd replace the solar charge controller, as has been said poor quality as the Amazon price of about $5 would confirm. Replace with a Victron unit will increase your current solar harvest considerably

 

[bicter]

Wiley

1. Size of all batterie/s in Amp Hours (AH) and chemistry: 102 AH Wet cell - As your fridge is a 3 way, you'll be running on gas/mains apart from when travelling. Normally the car alternator is used to keep fridge cold while driving but 12v on the 3 way sucks a lot of current.
As the battery is a wet cell, I trust it is either mounted externally or protected from naked flames and externally vented as explosive gas is given off these batteries when gassing.
2. Total current draw with everything operating: I imagine battery will only be running lights, pump and possibly a 12V TV/radio/ The question was asked to ensure you had sufficient battery capacity. For light use, 102AH shpuld be fine, though a TV could be power hungry. For longevity, avoid discharging battery too low
3. Type of fridge and P/No (ie 3 way or compressor type and capacity) N/A
4. Part number of the panel meter shown in last pic: I couldnt read the label.
5. Solar: Going by the dimensions of your panel, the probable wattage is 160W and thats a rough estimate.
As previously mentioned you should investigate the melted junction box and probably replace solar regulator with a more suitable regulator. Need to ensure the output voltage of the panel doesn't exceed the input voltage rating of the replacement regulator. Preference iss given to MPPT over PWM technology these days and the Victron unit is widely used however if you're on a budget then have a look at the EPEVER Tracer BN series mppt charger controller available on fleabay. Epever sell rebadged versions to cmpanies like Kings and Jaycar.

Unless budget dictates otherwise, try and ensure any new bits of Solar/charging are suitable for Lithium batteries as well as the usual charging profiles.

Now we have the majority of details, are there any specific questions we can answer?

 

[Gordon Jane]

Some great information there @bicter !

From my solar dealings, I've found that most MPPT regulators will do the job. Cheap or higher end. The output difference also is minimal at best.
What has been touched on is the longevity/reliability of the cheaper units. I have never had an issue with them tbh and like most things these days, even the reputable brands can fail.
Best thing on the cheaper units, you can carry a spare. Minimal outlay and only a few minutes to swap out if needed.

A basic multi meter is also a good thing to carry.

Regarding the fridge, mains will be your best option. Gas is fairly efficient with these (there are variables to take into account) so long as you don't need to also cook.
12V is purely to maintain coolness whilst in travel. Best to run your fridge prior to switching to 12V as it wont cool effectively from room temp on 12V. You will need to also ensure your car is setup for this. Most opt for a 12 pin, running a hot-wire. Some go with an Anderson plug.
12 pin would be the best option as you would have more spare pins to use. A simple 60A reset-able breaker is all you should need.

Regarding the panels, the bigger the better. Again though, i have found little difference in the cheaper mono-crystalline panels over the more expensive ones. especially when it comes to folding set ups.

Lithium batteries are the best, budget wise to continue with what you have maybe just invest in an AGM battery. Minimal fuss and they seem to (with my experience) tolerate unusual charging cycles as well as float charging.

Hopefully some of this might help

- GJ

 

[Moneybox]

I swapped out my four aging (9yrs) AGM batteries for two lithium batteries. So far I judge it to be a bad move. The AGM's are slow to charge and slow to discharge but are utterly reliable (three of them are now running a pump on the fish pond). The lithium batteries are the opposite, fast to charge and unreliable.

I saved about 100kg in the changeover and that was my main reason for the change. Since having the lithium batteries I've noticed them often running out of balance. It hasn't bothered me but one battery seems to remain quite stable while the other is often running a much higher voltage while on boost charge.

When it comes to discharge that's when the lithium lets me down. I used to be able to switch over to the AGM's for an emergency start when the truck batteries flattened for some reason. They fired up the engine with no issues. The lithium batteries give me perhaps 1 to 2 seconds of cranking before spitting the dummy and when they drop out it can take me half an hour to get them back online. Fortunately the Isuzu will fire up from cold within a second but I'm still left without the fridge running on anything else electrical until I can get the lithiums going.

The lithium batteries won't reenergise until ALL current draw is cut off. The battery isolator cuts power to most circuits but there's a slight discharge to the 24V - 12V converter while it's on standby. This milliamp discharge is enough to prevent the lithium coming back again so I have to pull the fuse on this device after the batteries have had time to settle down.

Then there's the problem of when the batteries are discharged. They just drop out without warning. It can be the middle of the night. We might have had a cloudy day and going to bed the voltage looks fine but the overnight discharge can have them drop out because the voltage remains high until right near the end then there's a sharp decline. If I'm aware of it I'll flick the truck batteries in before going to bed and then I can rely on the lead acid batteries keeping everything going until sun-up the the next day.

The lithium batteries are too temperamental for me. Give me a good set of AGM batteries any day.

 

[bicter]

I swapped out my four aging (9yrs) AGM batteries for two lithium batteries. So far I judge it to be a bad move. The AGM's are slow to charge and slow to discharge but are utterly reliable (three of them are now running a pump on the fish pond). The lithium batteries are the opposite, fast to charge and unreliable.

I saved about 100kg in the changeover and that was my main reason for the change. Since having the lithium batteries I've noticed them often running out of balance. It hasn't bothered me but one battery seems to remain quite stable while the other is often running a much higher voltage while on boost charge.

When it comes to discharge that's when the lithium lets me down. I used to be able to switch over to the AGM's for an emergency start when the truck batteries flattened for some reason. They fired up the engine with no issues. The lithium batteries give me perhaps 1 to 2 seconds of cranking before spitting the dummy and when they drop out it can take me half an hour to get them back online. Fortunately the Isuzu will fire up from cold within a second but I'm still left without the fridge running on anything else electrical until I can get the lithiums going.

The lithium batteries won't reenergise until ALL current draw is cut off. The battery isolator cuts power to most circuits but there's a slight discharge to the 24V - 12V converter while it's on standby. This milliamp discharge is enough to prevent the lithium coming back again so I have to pull the fuse on this device after the batteries have had time to settle down.

Then there's the problem of when the batteries are discharged. They just drop out without warning. It can be the middle of the night. We might have had a cloudy day and going to bed the voltage looks fine but the overnight discharge can have them drop out because the voltage remains high until right near the end then there's a sharp decline. If I'm aware of it I'll flick the truck batteries in before going to bed and then I can rely on the lead acid batteries keeping everything going until sun-up the the next day.

The lithium batteries are too temperamental for me. Give me a good set of AGM batteries any day.

MB,
Good summary on the Lithiums .
The main reason I see for using LiFeP04's is reduced weight, greater depth of discharge and greater charge/discharge (Discharge limited by BMS capability)
This, IMO, makes them ideal for Caravanning and other specific applications but the AGM/Lead acid is still needed dependent on requirements

Horses for courses

 

[user 22230]

Some great information there @bicter !

From my solar dealings, I've found that most MPPT regulators will do the job. Cheap or higher end. The output difference also is minimal at best.
What has been touched on is the longevity/reliability of the cheaper units. I have never had an issue with them tbh and like most things these days, even the reputable brands can fail.
Best thing on the cheaper units, you can carry a spare. Minimal outlay and only a few minutes to swap out if needed.

A basic multi meter is also a good thing to carry.

Regarding the fridge, mains will be your best option. Gas is fairly efficient with these (there are variables to take into account) so long as you don't need to also cook.
12V is purely to maintain coolness whilst in travel. Best to run your fridge prior to switching to 12V as it wont cool effectively from room temp on 12V. You will need to also ensure your car is setup for this. Most opt for a 12 pin, running a hot-wire. Some go with an Anderson plug.
12 pin would be the best option as you would have more spare pins to use. A simple 60A reset-able breaker is all you should need.

Regarding the panels, the bigger the better. Again though, i have found little difference in the cheaper mono-crystalline panels over the more expensive ones. especially when it comes to folding set ups.

Lithium batteries are the best, budget wise to continue with what you have maybe just invest in an AGM battery. Minimal fuss and they seem to (with my experience) tolerate unusual charging cycles as well as float charging.

Hopefully some of this might help

- GJ

Great first post is it "C" Feel like the fish on the line but I'll nibble

Can't agree on the quality controller making no difference to the cheapies as have seen the result to many times to deny the difference. Camp set ups running out of battery power by the end of the day, changed solar controller to quality unit and issue solved? 12 pin trailer plugs are not designed to handle charge feed. If not already fitted use an andersons as you can also use it to plug panels into and also other accessories if you so wish. Bit confused on the fridge comment as if I brought a fridge and it wouldn't effectively pull down on 12 volts it would go back to place of purchase ..................... very quickly. The 28 & 80 litre in my car is often turned on in ambient temps of 40+ degrees and still pulls down no issue? As said bit confused regards that ?

 

[user 22230]

MB,
Good summary on the Lithiums .
The main reason I see for using LiFeP04's is reduced weight, greater depth of discharge and greater charge/discharge (Discharge limited by BMS capability)
This, IMO, makes them ideal for Caravanning and other specific applications but the AGM/Lead acid is still needed dependent on requirements

Horses for courses

Weight loss has always been the appeal for me on lithiums but schools still out regards the value for dollars spent. AGM have done me well for many years.

 

[Gordon Jane]

Great first post is it "C" Feel like the fish on the line but I'll nibble

Can't agree on the quality controller making no difference to the cheapies as have seen the result to many times to deny the difference. Camp set ups running out of battery power by the end of the day, changed solar controller to quality unit and issue solved? 12 pin trailer plugs are not designed to handle charge feed. If not already fitted use an andersons as you can also use it to plug panels into and also other accessories if you so wish. Bit confused on the fridge comment as if I brought a fridge and it wouldn't effectively pull down on 12 volts it would go back to place of purchase ..................... very quickly. The 28 & 80 litre in my car is often turned on in ambient temps of 40+ degrees and still pulls down no issue? As said bit confused regards that ?

Always happy to be proven wrong @Diginit, That's how we learn!

Regarding the controller, that was, as mentioned in my experiences. Never have i had or seen an issue with the cheaper MPPT controllers. I also havent travelled for more then a few weeks at a time which may play a part in it, again where i mentioned longevity.

My comment regarding fridges not effectively running on 12V was aimed at caravan fridges specifically, not car/portable fridges. A caravan fridge has a 12V option which was aimed more so for use in transportation. Portable fridges such as Engel etc are designed for constant 12v use and your correct in saying they will pull from ambient. A caravan fridge switched on at ambient and transported using only 12v wont be as effective. We always ran our fridge on mains for a few days prior to leaving.

Regarding the 12 pin, you are absolutely right. Anderson plug is definitely the way to go however it wasnt uncommon to use (from memory) pin 9 as a hotwire to run a fridge. This was always only used in the smaller vans, with small fridges.

 

[grubstake]

Bit confused on the fridge comment as if I brought a fridge and it wouldn't effectively pull down on 12 volts it would go back to place of purchase ..................... very quickly. The 28 & 80 litre in my car is often turned on in ambient temps of 40+ degrees and still pulls down no issue? As said bit confused regards that ?

GJ is talking about 3-way gas/electric (absorption) fridges, in which the 12 volts is powering a heating coil with a consequent high power demand. They typically draw around 8 amps at 12 volts and run 24/7, with no thermostat. You're talking about the much more efficient compressor fridges which draw a lot less power and cycle on and off as necessary.

 

[user 22230]

ok fully understand the statement now and apology if required to you GJ for my presuming and miss understanding regards this. Indeed wrong on my part to have done so

 

[Gordon Jane]

ok fully understand the statement now and apology if required to you GJ for my presuming and miss understanding regards this. Indeed wrong on my part to have done so

I never read it that way mate, definitely not needed!

 

[wiley coyote]

WOW! Thanks for all that info Guys. I've now got a lot of options to consider to improve my system. I'll replace, or tighten any loose wires in the fried box first, (easiest). Then I'll replace the controller for a Epever Tracer. Huge choice though. From $14 to about $200. So will probably buy mid range. The battery's in the front locker, where you put all the tools for the caravan. It fits into an Aldi battery container secured to the floor, so it's sort of isolated from the tools. Awkward to get the battery in and out though. Had to use an engine crane. That was fun. Secured the crane chain to the battery handle. Half way out the handle snapped, and dropped the battery. Putting it back in, I hooked it up to the strap on the Aldi container. The plastic buckle on the container snapped and the battery hit the ground from about a metre up. I wised up then and chained it to the crane and got it in OK this time. All good fun! I'll be making a cradle with 4 chains on it to sit it in next time I need to lift it out. wiley.

 

[Moneybox]

WOW! Thanks for all that info Guys. I've now got a lot of options to consider to improve my system. I'll replace, or tighten any loose wires in the fried box first, (easiest). Then I'll replace the controller for a Epever Tracer. Huge choice though. From $14 to about $200. So will probably buy mid range. The battery's in the front locker, where you put all the tools for the caravan. It fits into an Aldi battery container secured to the floor, so it's sort of isolated from the tools. Awkward to get the battery in and out though. Had to use an engine crane. That was fun. Secured the crane chain to the battery handle. Half way out the handle snapped, and dropped the battery. Putting it back in, I hooked it up to the strap on the Aldi container. The plastic buckle on the container snapped and the battery hit the ground from about a metre up. I wised up then and chained it to the crane and got it in OK this time. All good fun! I'll be making a cradle with 4 chains on it to sit it in next time I need to lift it out. wiley.

I did exactly the same thing yesterday. I had to get one of the 1050CCA batteries out of China so I looped a chain through the two handles, raised it a couple of inches with it hanging from Zimba's bucket and the handle snapped. Then I looped the chain right around the battery and lifted it out one end up. It has two of these huge batteries and I don't want to buy one and have a new and an old so I'll just buy two N70 size so that I have two new matched batteries. First I have to find the slow discharge that killed the old battery so for now it has the fridge battery out of the Merc and that easily fires it up.

 

[wiley coyote]

Moneybox. I read your stories with great interest, as it's great to see a Master of Improvisation at work. We all learn by our mistakes , but unlike you, it took me 2 mistakes with lifting the battery to learn. wiley.