Solar The Solar Panel Thread

Apr 17, 2017
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Cairns
@Joves , i forgot to ask, are you sure the BMPro has an offset for the SOC display as in useable and actual SOC?

I had a read of a BMPro manual it is seemed to talk about low voltage cut out points, I didn't see anything about an offset.

What model BMPro is it again?
 
May 9, 2019
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Sydney
Hi all,

Thanks for your replies. It was a great shakedown trip, that is for sure. Aside from having some difficulty working out how to engage the third water tank, which I eventually did (I think... it was a bit spluttery) it really went off without a hitch!

As for the power to the fridge, I’m not wanting it to be a controversial issue. Perhaps the Power Hub is displaying incorrect readings. Entirely possible and something I’ll absolutely concede if it is the case. As far as I could tell, and according to the monitor, the fridge condenser sat idle for the vast majority of the trip. Whether or not this is the case, I have no idea. All I know is that the beer remained cold and the battery was still at 95% at the end of the trip. I agree, much better performance than I expected or could have hoped for. If it was a false reading, then I’m ok with that (aside from the fact that I’d rather an accurate one moving forward), as I’ll happily and easily charge the battery with the portable panel.

The panel will definitely be a godsend in future when we get the Anderson connected. I was surprised by how much the batteries drained with what I consider minimal usage. This weekend’s experience suggested to me that the usage was ok, but the charge input throughout the day was lacking. Does it sound right that 320w of roof panels would only be capturing a maximum of around 10amps (generously speaking)?

As for the water, I reckon we could comfortably get at least a week out of it if we are mindful of our usage. This trip has been a very good learning experience all-round!
 
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Likes: Crusty181
May 9, 2019
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Sydney
@Clewsy, the model is BMPro J35C.

It appears to be set for SOC at 100ah, whereas I have 200ah of battery connected to it, so it seems to base its readings on useable power. I’m certainly hoping this is the case, otherwise I’m definitely going to need bigger batteries!
 

Boots in Action

Well-Known Member
Mar 13, 2017
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Ferny Grove, Queensland
Hi all,

Thanks for your replies. It was a great shakedown trip, that is for sure. Aside from having some difficulty working out how to engage the third water tank, which I eventually did (I think... it was a bit spluttery) it really went off without a hitch!

As for the power to the fridge, I’m not wanting it to be a controversial issue. Perhaps the Power Hub is displaying incorrect readings. Entirely possible and something I’ll absolutely concede if it is the case. As far as I could tell, and according to the monitor, the fridge condenser sat idle for the vast majority of the trip. Whether or not this is the case, I have no idea. All I know is that the beer remained cold and the battery was still at 95% at the end of the trip. I agree, much better performance than I expected or could have hoped for. If it was a false reading, then I’m ok with that (aside from the fact that I’d rather an accurate one moving forward), as I’ll happily and easily charge the battery with the portable panel.

The panel will definitely be a godsend in future when we get the Anderson connected. I was surprised by how much the batteries drained with what I consider minimal usage. This weekend’s experience suggested to me that the usage was ok, but the charge input throughout the day was lacking. Does it sound right that 320w of roof panels would only be capturing a maximum of around 10amps (generously speaking)?

As for the water, I reckon we could comfortably get at least a week out of it if we are mindful of our usage. This trip has been a very good learning experience all-round!
@Joves , in answer to your question regarding output of 2 X 160W panels, the best you could expect would be 12 to 14A total in really optimal conditions. After deducting the fact that the panels are flat on roof of van and not necessarily placed in the best position towards the sun and not partially shaded, and the heat on the solar cells themselves (minus 0.5% output per 1 degree C above 25C - panel temps usually get up to 48 to 50C !) and the fact that panels will only have max sun for generation for approx 4 hours daily, a realistic estimate would be 6A per panel for 4 hours per day for a total of 48ah at best. If you continue to use 50ah daily as per your latest trip, you are never going to have full batteries and storage. Throw in a cloudy day and a wet, overcast day, and you are in trouble. Most members on this forum try to recover ALL power used each day before the afternoon and keep battery storage for the periods when it is rainy (limited recharging opportunities? ), and for use at night time. So in your case, you need to produce at least 50ah every day (60ah preferably) to stay in the race. Extravagant use of battery power just because it is there is not wise as you do not know what the weather will throw at you in the following days and possibly reduce solar charging to almost nothing, no matter how much solar you have! It then becomes a matter of how much storage you have and how quickly you can charge batteries up again with the solar AND supply current usage at the time. So many variables here - more solar power, more battery storage or reduce power consumption to below what you can regularly generate, and still have a safety margin to continue off grid. Tread your own path on these options.
 
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Drover

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@Joves I would take the panel reading of the BMPro as a roughy, you can change the SOC, at least on the ones I have played with .............. also they can be a bit touchy if theres a few connections on the battery terminal, they like to be the first on the post...................but be sure your batteries are hooked up as per that link I gave earlier and you don't have stray connections to seperate batteries, the joining cables should be on their Pat Malone.......

As for your fridge I'm not surprised, mine has kept the beer icy and used bugger all power at times of cool weather, enough that i checked it was on aux and not engine battery.............also no use looking at your power meter unless you have shut down everything for 30 mins otherwise you will get a false reading, I have a voltmeter at the end of the line and it gives a totally different reading to the one at the battery...but when everything is off and the batteries have settled they both show the same....Just get things nice then ignore it all and enjoy things.... I can pump 2 tanks of water in 2 days or make them last 7 days, depends how far restock is...........

At times when Ive bothered my 120w on the ground supplies more juice than the 200w on the roof and I would plug the portable into the utes Aux battery of an arvo once the van is up to speed............unplugging chargers for phones when done with, turning TV off and any invertors will save heaps of juice also I found the radios in vans chew a humungous amount of power compared to other things........
 
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Likes: Joves
Apr 17, 2017
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@Joves , jolly good, that makes sense on how it's set. Thanks

Some more trials of the drinks fridge will be in order to solve the case I'd say. I don't need much excuse to do "caravan research" in the interests of learning of course. We've found the fridge to use bugger all when it's cold too when we froze our buts off in Canberra recently. Use it as a fridge / freeze in warm weather is a massive difference. As long as she keeps drinks cold camp moral is sky high (that night at least)

Guys have good tips, it's a change of habit to turn things off when not using them and if you have a display screen you can see the differences which helps educate the family on what to do, takes time. Or you can put in more solar like your portable and more batteries or take a geny or turn the tug over and charge from it.

We're the same with water, if you have heaps and it's a short trip fill your boots, or conserse to string out your free camping.

One thing we do after free camping (or in van park) if we've used drain hose and we get back to water is put a standard garden hose spray on water hose and flush the grey water hose till to comes clear, damm thing is like your stomach, after too much "caravan research" there's always corn or peas that was consumed yonks ago!
 
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Fallen

New Member
Feb 7, 2019
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WA
Hi all, quick query, how long on average are everyone's original Jayco batteries lasting? I've just bought a 2015 van and want to go dual batteries so going to buy two anyway to have them matched, but just wondering if the one I have (now pretty much 5yo) is worth keeping as a Aux or spare (i.e. is it worth the extra 30kg)? Will take it to a battery place for a proper check, but was just interested in what people were getting re life of batteries.
 

Drover

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Nov 7, 2013
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Hi all, quick query, how long on average are everyone's original Jayco batteries lasting? I've just bought a 2015 van and want to go dual batteries so going to buy two anyway to have them matched, but just wondering if the one I have (now pretty much 5yo) is worth keeping as a Aux or spare (i.e. is it worth the extra 30kg)? Will take it to a battery place for a proper check, but was just interested in what people were getting re life of batteries.
Depends on type, size ,brand and how well it was looked after ............ An AGM battery could last 8 yrs if you looked after it, never going past 50%, keeping it charged on trickle all the time and kept at a comfortable temp .............. just charging it up before a trip then making it work itself hard for a couple of weeks before packed away, well you might get 3 yrs out of it.....
So its how long is a piece of string and a deep cycle battery doesn't test the same as a cranker........ I have had them last for 2.5 yrs, it had a short and melted, very scary and of course just out of warranty and the pothers are rolling up to 5 yrs.
If you replace with 2 new ones, shop around as there are some with a Big Name tax on them and they don't seem to do any better than say an Excide. Mine are kept charged by the solar panel all the time don't go GEL though as they more expensive than AGM and if you need to replace one they aren't always an off the rack job when travelling.

If your going to fit out with 2 new ones, go AGM, same size, brand and wire them up as per this link,
https://caravanchronicles.com/guides/how-to-connect-two-batteries-in-parallel/
Use proper cable and fittings and don't blindly follow the original hook up, its also a good time to check that the actual fuse labels are in line with the tags ie: the light fuse is actually for the lights sort of thing.

Contrary to all the talk I have had 2 batteries, 18 mths apart in age working away happily with no apparent power loss for a couple of years now, might be lucky !!!!
 

Fallen

New Member
Feb 7, 2019
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Awesome, thanks Drover. Was just reading the write up in that exact link this morning! Yes going AGM (although I heard that they don't like being on trickle all the time, top them up before packing up for a while and they hold enough charge over time that another top up is all that is needed before heading out again?).

Will check the existing set up thoroughly when I have plenty of time at home, as I want to be able to troubleshoot quickly when $&#@ goes down out and about.

Looking at something like the Mobi, seems like a common rebrand unit, which has a 20% off code right now

Link
 
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Boots in Action

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Mar 13, 2017
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Awesome, thanks Dover. Was just reading the write up in that exact link this morning! Yes going AGM (although I heard that they don't like being on trickle all the time, top them up before packing up for a while and they hold enough charge over time that another top up is all that is needed before heading out again?).

Will check the existing set up thoroughly when I have plenty of time at home, as I want to be able to troubleshoot quickly when $&#@ goes down out and about.

Looking at something like the Mobi, seems like a common rebrand unit, which has a 20% off code right now

Link
Hi @Fallen , all that @Drover said above is correct. As far as life is concerned, perhaps the following TRUE story will be of interest to you and others.
Grumbling vanner complaining bitterly about his two new batteries he recently installed so he could run his Sleep Apnoea machine when Off Grid. Only lasting less than 3 years!! I asked the following questions. "How often do you use van and what do you do when you get home after being away?" Reply "Only two or three times a year and I always put van away in friend's shed until next time The batteries should be fully charged by the car on the run home of over 300kms, so I never worry about batteries until next time I want to go out. But then I put them on charge for a few hours before travelling . Now they won't even hold a charge for long when I am connected to 240 volt power in a van park. Batteries should last longer than that and they cost a lot of money".

And here are some of his problems answered: Firstly, batteries should never be run discharged below 50% capacity. In fact once battery voltage drops below 11.8 volts, it is on the slippery slope to non full recovery. Secondly the car alternator WILL NOT recharge battery to full capacity, no matter how far you travel. Only with a DC to DC charger will that ever happen! AGM batteries require between 14.4 and 14.7 volts and Gel require between 14.2 and 14.4 volts - figures not obtainable on today's modern alternators. Thirdly, batteries should be fully charged as soon as possible for at least 36 but preferably 48 hours or longer to obtain full capacity. Even though AGM batteries quote only 3% loss of charge each month (at 25C), sulphation builds up on the plates and the longer it is there, the harder it gets to remove and be dissolved into electrolyte! Today's modern "smart" chargers have ability to sense voltage and "Float" charge batteries without damage for long periods, something that happens when properly charging. And as for charging for just a few hours before use is also of only limited value. It may only put in a "surface" charge, as insufficient time is allowed for plates to absorb full storage (or "soak") whilst charge current is being applied. Some "smart" chargers have 7 stages or more, but the main stages are Bulk, Absorb and Float. If charger is allowed to completely do that , you will get the max power out of battery so it lasts longer too. Also, better to run battery down to approx 70% or so and then recharge, rather than run it down to 50 to 60% and then recharge.
Battery in my Penguin (120ah AGM) is now more than 6 years' old and still holds charge well and provides full power when ever I want it.Attached are some points which have been well and truly covered before.
 

Attachments

Feb 7, 2019
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Appreciate the attachments BiA. Lots of reading today on here and other forums. The stock Setec is seemingly a poor choice to charge the batteries from a low charge (60% or so), but it would seem to be OK to keep the batteries trickle charged when not in use at home. Or would the 120W roof panel be sufficient (even if under a caravan cover it sounds like they still get some sun).

Plan is to use the rooftop and 300W of portable to recharge when at caravan parks and free camping. Then the rooftop for driving and at home (with maybe the Setec on at home every now and then until I get another panel on the roof).
 

Drover

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That sounds like the go, I just use rooftop (200w) when on road and at parks I don't even turn my 240 charger on, free camps I plug in the portable (120w) and since Big Mal cops the sun all the time the solar does the job when parked up, I would though if under cover use the Setek when at home and turn the solar off if your set up allows. Make sure you have soft corners on your roof panel so it doesn't eat your cover.
 
Likes: Fallen
Mar 13, 2017
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Appreciate the attachments BiA. Lots of reading today on here and other forums. The stock Setec is seemingly a poor choice to charge the batteries from a low charge (60% or so), but it would seem to be OK to keep the batteries trickle charged when not in use at home. Or would the 120W roof panel be sufficient (even if under a caravan cover it sounds like they still get some sun).


Plan is to use the rooftop and 300W of portable to recharge when at caravan parks and free camping. Then the rooftop for driving and at home (with maybe the Setec on at home every now and then until I get another panel on the roof).
Hi @Fallen, there is really nothing wrong with the stock Setec ST20 Series III or the stronger ST30. The former will charge up your batter/ies from any voltage above 11.8 volts?? at a rate of up to 10amps, which is the preferred method if connected to the grid. After all, it would work all day and all night if necessary, (okay only limited to 10A) but better than solar in poor conditions. If off grid and depending on solar power, you are limited to what the panels can provide. Your suggestions seem fair enough if you can monitor battery usage and voltage. The limitations of the Setec are the "low" max charge voltage of 14.0 volts when your AGMs need up to 14.7 volts to attain full charge and the lower charge rate of only 10A. The "float" voltage of 13.8 would be fine from Setec once full charge has been attained and it has changed to "float". Additionally, the Setec (without the solar input) has the ability to regularly go into "Store" mode at a lower voltage of 13.2 volts which prevents any unnecessary charging and deterioration of Positive plate/s. The main consideration for off grid will be the setting for max charge voltage on your solar controller/s. A lot are fixed at 14.4 volts max charge and 13.8v for float. The better ones (most MPPT controllers) have user adjustable settings for these, so you have the ability to set max charge voltage for your AGMs at 14.7 volts. If connected to the grid, there would not be a need to use solar panels normally, but as you have a panel on roof working in conjunction with the SETEC, the Setec will charge up to 14.0 volts and the solar controller (when able to charge) will continue to charge battery/ies to the higher voltage, until it too drops back to Float. So to sum up, suggest use Setec when connected to grid, use solar when off grid and use a “smart” charger with AGM setting at home until it is in “float” mode, then connect to Setec and let it look after battery/ies until you use van again. That is what I do anyway, but you can tread your own path on this. Cheers
Battery Maintenance.jpg
Battery Maintenance.jpg
 
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Dec 2, 2019
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Hi All,
Just thought I would share some information passed on to me that helped with my installation.
The setup consists of 6 2SG250 Sungel batteries, PL40 regulator and 1x180w panel.
When designing what I required, emphasis was paid on the total loading over the 24 hours.
The RAPS engineer advised me to build around having the batteries fully charged and on float by midday, daily.
So setting up the regulator as per the battery manufacturers specifications, I have a system that has never let me down,
never gone flat, never dropped below 50% of charge and is now 11 years old without maintenance.
The engineer specifically stated that most of the problems with solar battery management is the correct parameters being set in the regulator.
He advised that the reg's are smart enough to provide complete management for the batteries if set up correctly from the jump.
The load on the system is 2 Engel 60L units. Set on refrigerate only and operating on the thermostats, they have never failed or been starved for voltage.

Torque
 
Likes: Drover
Dec 2, 2019
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Perth
Hi Mike,

I cant remember what we designed on.
When the fridges are packed, online and working on the thermostats, I haven't seen the battery voltage below 12.4 first thing in the morning.
I wish I could find the calculations but it was a while ago.
I know we pre chilled everything before packing them so the load would be reduced.
One thing we put some effort into was making sure the fridges had really good positive ventilation over the condensers.

Sorry

Torque
 
Mar 13, 2017
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Ferny Grove, Queensland
Interesting post.

Do you happen to know the power used per day in Ah for both Engel fridges?

cheers
Mike
Interesting post.

Do you happen to know the power used per day in Ah for both Engel fridges?

cheers
Mike
Mike @mikerezny , I had a look at these batteries on my computer. They are only 2 volts each, but in the 120 hour test are rated at 682ah. If I understand the data correctly the 6 batteries connected in series would have 12 volts with an ah capacity of 682ah. That is a lot of storage, but at 33kgs per battery, it would be a lot of weight too at nearly 200kgs. I for one would not be able to carry such extra weight let alone pay for such a system. No doubt they can supply power for a long, long time with that much storage, but I would have my doubts that only 1 X 180 watt panel (the PL40 is a 40A PWM type regulator) would be able to fully charge this system every day and replace the ah used with 2 Engel fridges running 24 hours per day. I am looking forward to further information from @Torquelimited .
 
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Drover

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Feb 7, 2019
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Looks like the stock Jayco circa 2015 solar reg (TPS 1230) only outputs up to 14.5v +/- 0.4v, so I might need to find one more suited to AGM batteries. Unless the +/- here is less about tolerance of components and more about adapting to battery types?