Journey New Solar panels for my JJOB

[Hitting the road]

The time has come to upgrade the solar panels on the roof of my JJOB pop top. I upgraded the batteries to 2 x 135 amp Lithiums a while back, (saving 40kg on the old AGM's I had fitted), but the roof only has the original factory panel...I think it is 160w being a 2018 build. Original battery was a 100amp AGM so that panel was probably adequate. Having to put out the folding panels when ever off grid for a couple of days is a pita.
So, I have bought 2 x 200w Sphere panels, they just happen to be the same outside dimensions as the original panel which I assume would be a Sphere as well.

So, one panel will slot in to the existing brackets on the roof, the other will go down the behind the air conditioner on the same side, keeping as close to the middle as possible to reduce lifting effort. I plan to use existing wiring from the current panel through to the MPPT inside, panels wired in series so the cabling already there should be adequate for the 40 volts / 8 amps generated.

I have a third 135amp Lithium I bought at the same time as the other two...I want to fit that to the existing two battery pack in the van, but the space under the seating area where all the electrical is fitted is now very tight. (The Lithiums I have will accept up to four batteries in parallel or series). Not sure yet how I am going to tackle that yet. I have looked at it several times, with and without holding a beer, and haven't come up with an easy solutions as yet. I don't want to move everything as that really isn't practical.

When I figure it all out I'll come back with the solution...I hope...lol

 

[Drover]

Best bet with the batteries is to make a new spot for them, having them on different size leads is not wise .... drop down rack underneath floor, they will lay on their side in a box happily enough is one option. ....

Have looked at series for my set up but talking to other campers who DiY, and some have gone back to parallel as shadow issues from even the AC are a source of frustration it seems and others like me use a combination of roof and portable so shade doesn't bother them if series or parrallel as breaker fitted means easily shut down roof section.

 

[Hitting the road]

Thats the thing...I want the batteries near side by side so all the cables are quite short joining them together. I don't really want to mount them underneath as ground clearance may become an issue leaving them exposed to hits. I do have some ideas though...

Pretty well what my plan too re panels. I will still carry the 2 x 200w portable panels and plug them in if I have the van parked in the shade. The roof panels will charge the batteries while on the move as well, as I have not fitted plugs etc to charge the van batteries while hooked to the tug on the move. I will fit a switching system so that I can have the 2 roof panels charging, or the 2 portable, or all 4 if I desire.
I don't particularly want to go down the road of fitting a DC DC charger in to the van to top up batteries, there is one in the tug now that keeps the fridge battery charged.
The air cond could potentially shade one of the panels very late in the day with the sun low in the sky I guess, but I'll put up with that as I don't want to replace the existing cables for the solar panels. If in parallel I would be concerned the existing cabling is not really heavy enough to satisfactorily carry 15 amps plus which paralleled panels could see. But I think they would be ok to carry some higher voltage...

 

[Drover]

AC shading does depend on how your parked, mine it can shadow in certain positions up to 1000 and from 1430ish ................ roof top only of much use from 1030 to 1430 or less anyway thats why I like the protable parked out when we are parked up for a few days, all fully charged before the sun is high and can fire up the invertor and not burn any battery power just using the panel juice............

I doubt your cabling would have any drama carrying the amps really but size it up and see, the run isn't really long enough I imagine to be an issue, been going to size mine one day but it all seems to work fine...... 440w how many amps well in theory around 24amps.... but thats rarely seen if ever...nothing melted so far........................... I have fitted just a normal DC 40a breaker to shut down the roof panels and the feed from the portable taps in between it and the Epever so it can run with or without the roof jobbies and there's an 80a on the battery side of things to shut it down easily, actually it seems if the battery is shut down the Epever will run the van power on its own, I knocked the battery off once, panels still on and things were still working, most interesting I thought but haven't looked further into it yet, assume the Epever just responded to demand.....

Weve had Big Mal for 9 or 10 years and its never had the capability to charge from the tug, only draws fridge power, its an off grid rig and has never needed it , we travel for a month or so and never use shore power so can't see why its needed for a few hours driving every week or so. but then thats just me...

Do you really need 3 batteries actually, do an inventoryof power use , may find you have surplus storage, I had a mate who would carry a charged up battery in his ute for just in case ............... Stack then up on their side in a cupboard, does the new regs apply to retrofitting of them ?????

Yarning with a sparky who fits a lot of work utes and stuff, he showed me some wonderous bits of kit, modular units , the $$$ spent makes your eyes water but he said when he sets up the lithiums he sets the battery capacity at about 20% less than actual and like me dials down the charging settings a little bit, he said then when the battery runs down and shuts off its not dead/dead it has some capacity left so recovery is easier and they don't kill the batteries quickly... he said he builds and fits these systems for people who have no idea so sets them up to be virtually fail safe from idiots, setting them at max isn't a good idea for longetivity ..... he actually thought my set up was great, simple,functional and KiSS .............

 

[Boots in Action]

AC shading does depend on how your parked, mine it can shadow in certain positions up to 1000 and from 1430ish ................ roof top only of much use from 1030 to 1430 or less anyway thats why I like the protable parked out when we are parked up for a few days, all fully charged before the sun is high and can fire up the invertor and not burn any battery power just using the panel juice............

I doubt your cabling would have any drama carrying the amps really but size it up and see, the run isn't really long enough I imagine to be an issue, been going to size mine one day but it all seems to work fine...... 440w how many amps well in theory around 24amps.... but thats rarely seen if ever...nothing melted so far........................... I have fitted just a normal DC 40a breaker to shut down the roof panels and the feed from the portable taps in between it and the Epever so it can run with or without the roof jobbies and there's an 80a on the battery side of things to shut it down easily, actually it seems if the battery is shut down the Epever will run the van power on its own, I knocked the battery off once, panels still on and things were still working, most interesting I thought but haven't looked further into it yet, assume the Epever just responded to demand.....

Weve had Big Mal for 9 or 10 years and its never had the capability to charge from the tug, only draws fridge power, its an off grid rig and has never needed it , we travel for a month or so and never use shore power so can't see why its needed for a few hours driving every week or so. but then thats just me...

Do you really need 3 batteries actually, do an inventoryof power use , may find you have surplus storage, I had a mate who would carry a charged up battery in his ute for just in case ............... Stack then up on their side in a cupboard, does the new regs apply to retrofitting of them ?????

Yarning with a sparky who fits a lot of work utes and stuff, he showed me some wonderous bits of kit, modular units , the $$$ spent makes your eyes water but he said when he sets up the lithiums he sets the battery capacity at about 20% less than actual and like me dials down the charging settings a little bit, he said then when the battery runs down and shuts off its not dead/dead it has some capacity left so recovery is easier and they don't kill the batteries quickly... he said he builds and fits these systems for people who have no idea so sets them up to be virtually fail safe from idiots, setting them at max isn't a good idea for longetivity ..... he actually thought my set up was great, simple,functional and KiSS .............

Hi Ian @Drover and @Hitting the road, I was aware of the issue regarding connecting outputs from MPPT controller DIRECTLY to loads without a battery/ies supply, so decided to look up the data. Certainly, any such action would throw the MPPT controller into a hissy fit as varying current and voltage drains from loads would make control difficult if not impossible. The battery/ies connected between the solar output and the loads acts as a huge capacitor and smooths the current demands. It seems that Victron also does not recommend such action in the attached link.

Can MPPT charge controller be used without a battery? - VictronEnergy

communityarchive.victronenergy.com

 

[Drover]

Hi Ian @Drover and @Hitting the road, I was aware of the issue regarding connecting outputs from MPPT controller DIRECTLY to loads without a battery/ies supply, so decided to look up the data. Certainly, any such action would throw the MPPT controller into a hissy fit as varying current and voltage drains from loads would make control difficult if not impossible. The battery/ies connected between the solar output and the loads acts as a huge capacitor and smooths the current demands. It seems that Victron also does not recommend such action in the attached link.

Can MPPT charge controller be used without a battery? - VictronEnergy

communityarchive.victronenergy.com

I thought as much, had a look at my Epever manual and while my model/version can't later models of the Epever actually can operate safely if battery disconnects, will have a look to see if there is a firmware upgrade as it could be a handy thing to have, just need some candles for dark time......... Thinking back I was wondering how it actually was working as no 12v to activate things but if I had my Breaksafe on charge then that could have been the 12v needed to make the controller stay in operation .............

 

[Hitting the road]

I note the MPPT's have a set of terminals to connect directly to a load, as well as to a battery pack. I haven't ever connected directly to those terminals, but I guess one could, but as Boots wrote and Victron too, a battery should be connected to regulate voltage and smooth out any lumps.

I have done a power usage "inventory", and according to my figures, being reasonably frugal, they read I could possibly get up to 10 days off grid with zero input to the existing batteries...using up to 80% of charge...but nothing is perfect so I'd think 7 days may be possible.
I will likely fit an inverter down the track somewhere for convenience...(hair dryer for the bride and occasional microwave oven). So, in the short term 400amps could be an over kill for sure, but looking at longer term plans...

 

[Drover]

Most Controllers have a Load terminal this is just to supply the power to the van loads and allows the controller to display what power is used compared to what is made, not to be used for high amperage devices like compressors though, in some vans it can be seen that only the red terminal in the load is used, this is because the builder has saved money on wiring and taken a short cut, the load won't work on these until a rewire of the van connection usually on cheapy PWM units so not an issue anyway ... also most controllers if not connected to a battery they won't work as they need to see 12v power before they will boot up.



I originally didn't run the load from my Epever but Boots talked me into it, so I gave it a go, the Epever displays lots of data at a glance so I have kept the van loads running through it, well most of course the inverter and external power anderson run from the battery Buss, I don't think the Epever would appreciate it if I ran the compressor thru it... and with Buss Bars its all so much easier and neater and I know exactly what going on, no annoying crap hanging off the battery either.

The battery has only one set of cables connected which then run via a breaker to a Buss bar the battery feed for the Epever runs from it, the Load from the Epever goes to a Buss bar which has the van feed, diesel heater and media circuit all fused connected to it, the solar panels go direct to the Epever via a breaker with a junction from the external solar anderson between the breaker and Epever...

Only have a 600w invertor and Im surprised at how little it actually draws when in use, though only for laptop, drill charger mostly, not enough for a hair dryer it does run a massage machine as well................ Been thinknig about another 120ah job but then I would have to redesign my battery box and make a bigger slide out .......

 

[Boots in Action]

Most Controllers have a Load terminal this is just to supply the power to the van loads and allows the controller to display what power is used compared to what is made, not to be used for high amperage devices like compressors though, in some vans it can be seen that only the red terminal in the load is used, this is because the builder has saved money on wiring and taken a short cut, the load won't work on these until a rewire of the van connection usually on cheapy PWM units so not an issue anyway ... also most controllers if not connected to a battery they won't work as they need to see 12v power before they will boot up.



I originally didn't run the load from my Epever but Boots talked me into it, so I gave it a go, the Epever displays lots of data at a glance so I have kept the van loads running through it, well most of course the inverter and external power anderson run from the battery Buss, I don't think the Epever would appreciate it if I ran the compressor thru it... and with Buss Bars its all so much easier and neater and I know exactly what going on, no annoying crap hanging off the battery either.

The battery has only one set of cables connected which then run via a breaker to a Buss bar the battery feed for the Epever runs from it, the Load from the Epever goes to a Buss bar which has the van feed, diesel heater and media circuit all fused connected to it, the solar panels go direct to the Epever via a breaker with a junction from the external solar anderson between the breaker and Epever...

Only have a 600w invertor and Im surprised at how little it actually draws when in use, though only for laptop, drill charger mostly, not enough for a hair dryer it does run a massage machine as well................ Been thinknig about another 120ah job but then I would have to redesign my battery box and make a bigger slide out .......

If you do not run the van loads through the MPPT solar controller LOAD terminals, the controller will not be able to display amps OUT , amp hours used and other data. Previous to the full introduction and proper use of MPPT controllers WITH A DISPLAY, there was no way of knowing load discharge through individual or total loads in watts, amps and amp hours. The best one could do was look at the battery percentage (time left in battery capacity in minutes at the current draw), but that was only possible with a shunt in line, probably sufficient for those not up, or interested, with current IN and OUT and other electrical data. This was (and still is?) common on earlier vans and only recently upgraded for later models. It should be noted that usually max current draw through controller is limited to the same level as charge output, but not always with the cheaper MPPTs and PWMs. Without a display screen though, there is little advantage.

And another important consideration.... solar controllers need to see at least the nominal battery voltage PLUS one volt (or more?) in the initial hook up before they will operate. If you have a flat 12 volt battery at say 11.0 volts or lower, not only will controller not recognize what voltage to charge at, but until the controller sees battery voltage plus say 3.0 volts at controller, no charging will occur. However, once this is done initially, the controller recognizes the battery system and loads and will operate normally. Have had campers come to me with a flat battery and a new controller which was never initialized wondering why not charging even though solar panel in full sun and no loads..

Might do an article on how to correctly connect loads through solar controller for those who are thinking about it as it has caused some confusion with members, even @Hitting the road, and he is pretty up with electrical systems.

 

[Drover]

If you do not run the van loads through the MPPT solar controller LOAD terminals, the controller will not be able to display amps OUT , amp hours used and other data.

Isn't that what I said ??? In laymans terms..............

My old PWM displayed all that stuff but then it wasn't a cheapy .......................

Too many variables with units to do a run down on controller set ups for loads .................. and nowadays no need to have the controller with display or even handy, do away with rewiring stuff just add a WiFi shunt to battery and bingo all the info on your phone , on some vans about the only way if you want to upgrade from a crappy PWM to a MPPT unit when space is limited and no display means a smaller unit and in most cases the battery is hairy with multiple connections hanging off it and be impossible to re-route them easily ..................
I would prefer a remote display which is probably possible depending on the WiFi shunt i suppose and how many $$$ you have to throw at it.........

 

[Hitting the road]

I don't run any loads through the MPPT at all. The MPPT controller in my set up has the solar panels connected in, and to the battery pack out. I don't really need to see any amperage in/out readings on the MPPT, (I can read solar input directly off the MPPT), as I still use the originally fitted BMPRO BMS to distribute and fuse all van connections.

Being I have fitted Lithium batteries replacing the original AGM I added a 20 amp Victron Lithium compatible charger to the system and isolated the charging from the BMPRO as it was not Lithium compatible.
As well being both the batteries have a 150amp built in BMS they are capable in parallel of 300amp output, therefore I have fitted a 300amp (Bluetooth) shunt at the battery pack negative.

The original remote JHub reader now bluetoothed from the shunt won't display the solar input though, I queried as to why with BMPRO and they tell me it is because the solar panels aren't connected to the BMPRO BMS. Fair enough, but you'd think that as the MPPT is supplying solar input via the shunt that info would be visible...not that simple it seems, What it does do is subtract inputs...so if there is say 10 amps of solar going in, and 6 amps being used, it will display an input of 4 amps...not great...just as the JHub also now won't display "charging" when on shore power indicating the batteries are charging...it only shows the actual voltage at the battery terminals... Limitations of the JHub remote reader...
I only really keep the JHub reader for simplicity as it also displays fresh water and grey tank levels...It works, could be a better setup for sure...

In summary I simply have the positive cables from the MPPT, BMS and battery charger connected directly to the positive battery terminals, and all the negative connected directly to the shunt which is connected to the negative battery terminal. Unfortunately there is no room at all for any busbars to make it look neater...

 

[Drover]

Sounds like youv'e cobbled together a workable economic system, you will never be able to get all the info on one display as 2 different systems doing their thing ................. All sounds good to me, set and forget being the way to go......................

Could you lay the batteries on their side and stack 2 on top of each other under the seat ??????

With the extra solar panels the mains charger is probably redundant as well, it is with mine.........

 

[jazzeddie1234]

What it does do is subtract inputs

My 3rd party battery monitor does this too so I have to look at the solar controllers to see what the panels are doing. After a while I got to know the typical sum of inputs and outputs was during the day (something like +15 amps with the fridge running until full charge) so I only need to check if it was quite different to this number.