18' Series Battery & Solar Help

[RD2021]

Hi All, I'm hoping some some help, please.

Current setup:
- 160w solar on roof, connected into BMPro J35B
- two 100Ah, AGM deep cycle batteries
- Anderson plug wired direct to battery (for additional solar input)

I would like to increase solar up to ~300W total by adding a portable solar blanket connected via the Anderson plug. I was also thinking of getting a MPPT controller (Victron?).

Without a shunt, is there any way of understanding what the actual battery levels are, given solar blanket is direct to battery / not connected to BMPro?

As it currently stands, it appears to me that I will have two systems (one connected directly to battery via solar blanket, one connected via BMPro).

I have only just purchased my first Caravan (second hand) so this is extremely new to me. I appreciate any help you can give.

Regards
RD

 

[Boots in Action]

Hi All, I'm hoping some some help, please.

Current setup:
- 160w solar on roof, connected into BMPro J35B
- two 100Ah, AGM deep cycle batteries
- Anderson plug wired direct to battery (for additional solar input)

I would like to increase solar up to ~300W total by adding a portable solar blanket connected via the Anderson plug. I was also thinking of getting a MPPT controller (Victron?).

Without a shunt, is there any way of understanding what the actual battery levels are, given solar blanket is direct to battery / not connected to BMPro?

As it currently stands, it appears to me that I will have two systems (one connected directly to battery via solar blanket, one connected via BMPro).

I have only just purchased my first Caravan (second hand) so this is extremely new to me. I appreciate any help you can give.

Regards
RD

Hi @RD2021 and welcome to the forum. Your request will no doubt get several different ideas from experienced members. IMHO, this is my understanding and best ideas:
Your connection of Anderson plug directly to battery may cause conflict between the solar controller in your BMpro J35B and the in line solar controller on your solar blanket. So preferable to have ALL solar input through the one controller (you need to bypass the controller on solar blanket), provided the BMPro J35b has the capacity to handle the added input. If that is NOT the case, then still have ALL the solar input through a higher rated solar controller which is wired directly to the battery, not through the solar input on BMPro. A Vitron MPPT controller with a capacity to handle around 30A would be necessary to handle both solar inputs. Be aware that the outputs of both panels will probably only generate a max of 25A on even a perfect day under perfect conditions which you never get as the output test is based on lab conditions (rated at 18.0v panel voltage - 300 divided by 18 equals approx 16A and 160 divided by 18 comes to approx 8A). so I would I reckon on approx 12A max on 300w blanket and around 6A for roof solar in real field conditions. The Vitron MPPT controller may improve output by up to 30% though. Also the Vitron MPPT controller has all the necessary settings and displays to enable you to monitor battery charging and voltages. Current output for loads will only be shown if Loads are connected through the Vitron OUTPUT terminals (see instructions) or otherwise a separate shunt will be necessary.

 

[Boots in Action]

Hi All, I'm hoping some some help, please.

Current setup:
- 160w solar on roof, connected into BMPro J35B
- two 100Ah, AGM deep cycle batteries
- Anderson plug wired direct to battery (for additional solar input)

I would like to increase solar up to ~300W total by adding a portable solar blanket connected via the Anderson plug. I was also thinking of getting a MPPT controller (Victron?).

Without a shunt, is there any way of understanding what the actual battery levels are, given solar blanket is direct to battery / not connected to BMPro?

As it currently stands, it appears to me that I will have two systems (one connected directly to battery via solar blanket, one connected via BMPro).

I have only just purchased my first Caravan (second hand) so this is extremely new to me. I appreciate any help you can give.

Regards
RD

Hi again @RD2021 , just had a look at the specs for the BMPro J35B and note that the solar regulator in that unit is rated to 29 amps so there is no need to go to a Vitron controller unless you want a MPPT controller. If extra solar from solar blanket is wired into the BMPro in parallel with the roof top panel, that should work fine (and provide battery voltages as well) as long as you bypass the solar blanket controller. Good luck!

 

[RD2021]

Hi again @RD2021 , just had a look at the specs for the BMPro J35B and note that the solar regulator in that unit is rated to 29 amps so there is no need to go to a Vitron controller unless you want a MPPT controller. If extra solar from solar blanket is wired into the BMPro in parallel with the roof top panel, that should work fine (and provide battery voltages as well) as long as you bypass the solar blanket controller. Good luck!

Hi @Boots in Action and thank you for your welcome and reply!!

Sorry, I should have been clearer. I'm aiming for 300W in total (160W on roof + 140W solar), which sounds like the BMPro J35B can handle (no need for a MPPT controller).

How would I go about wiring the solar blanket connection into the BMPro in parallel with the roof panel? My current Solar connection is below (circled in yellow)? I am unsure how 'two connectors' can go onto the connection point (circled in yellow).

Thanks again for your time and help. Hopefully one day I can contribute to the discussion.

 

[Drover]

Personally I would just go the way you have things at the moment, less drama and expense, the BMPro display will show the charge in your batteries, how much is being drawn from them for use in the van, it just won't show how much juice is being provided by the portable, which isn't really a biggy and doesn't make any difference to the operation of your system, depending on the controller on your portable if its removable or not and if you see a need to upgrade it, if you upgrade it get one with a screen then you can see what its doing..........
I would do a few camps to just see how things run before throwing $$$ on a possibility, often the gain isn't there and running new cable runs to the BMPro can be a pain if not impossible in some vans..............
My set up I can run all my panels thru the main controller or have the portable direct to battery via its own controller, and swapping them around I haven't found any noticable changes until the batteries are in float mode where the roof tops (420w) will shut down as the portable (120w ) is getting more sun...

Have a good read of the BMPro manual for your model, if your batteries drop below 11.6v the BMPro will stop drawing from them but will also stop charging them until they get up to 12.6v or something, a stupid idea as I have had to pull batteries out and charge them up on the bench before refitting and getting the system to work again, not a handy thing if off grid........ if you disconnect all the solar from the BMPro it will have a hissy fit that I do know.

 

[RD2021]

Perfect, thanks both @Drover and @Boots in Action

I will report back once I've had my first few camps!

 

[Boots in Action]

Personally I would just go the way you have things at the moment, less drama and expense, the BMPro display will show the charge in your batteries, how much is being drawn from them for use in the van, it just won't show how much juice is being provided by the portable, which isn't really a biggy and doesn't make any difference to the operation of your system, depending on the controller on your portable if its removable or not and if you see a need to upgrade it, if you upgrade it get one with a screen then you can see what its doing..........
I would do a few camps to just see how things run before throwing $$$ on a possibility, often the gain isn't there and running new cable runs to the BMPro can be a pain if not impossible in some vans..............
My set up I can run all my panels thru the main controller or have the portable direct to battery via its own controller, and swapping them around I haven't found any noticable changes until the batteries are in float mode where the roof tops (420w) will shut down as the portable (120w ) is getting more sun...

Have a good read of the BMPro manual for your model, if your batteries drop below 11.6v the BMPro will stop drawing from them but will also stop charging them until they get up to 12.6v or something, a stupid idea as I have had to pull batteries out and charge them up on the bench before refitting and getting the system to work again, not a handy thing if off grid........ if you disconnect all the solar from the BMPro it will have a hissy fit that I do know.

@Drover , I seem to be looking at a different set of specs for the BMPro J35B as per link below. The LVD is 10.8v plus/minus 0.2v and LVR is the same. I cannot find anything about what happens to charging or discharging when batteries drop to below 11.6v and not start carrying the load again until 12.6v is achieved. Although the manual does state that the unit is not capable of recharging a deeply discharged battery which needs to be removed and charged with a stand alone ("smart') charger, at what stage of discharge (or low voltage) is considered "deeply discharged" if the LVD is working?? Perhaps I am missing that information somewhere or you have found that out from field experiences??

J35B-L - Intelligent Power Management System | BMPRO

J35 Model B-L is an intelligent Power Management System with a multi-stage battery charger, delivering a total current of 35 Amp. Designed for Jayco caravans

teambmpro.com

 

[Drover]

Yes @Boots in Action your probably right in regard to the LVD, I just couldn't be naffed looking it up so took a guess, I knew if it was wrong you would correct it but the rest about recharging is right and it may be lower than 12.6 but the 2 of these units I've played with both did the same thing and at the time I wanted a solution, so remove batteries, charge the things up, luckily had 2 chargers, put them back in next morning and they have played the game ever since both times faulty light switches drained the batteries with one 240 lead not truned on and the other shoddy wiring no charge..

 

[Boots in Action]

Yes @Boots in Action your probably right in regard to the LVD, I just couldn't be naffed looking it up so took a guess, I knew if it was wrong you would correct it but the rest about recharging is right and it may be lower than 12.6 but the 2 of these units I've played with both did the same thing and at the time I wanted a solution, so remove batteries, charge the things up, luckily had 2 chargers, put them back in next morning and they have played the game ever since both times faulty light switches drained the batteries with one 240 lead not truned on and the other shoddy wiring no charge..

Not all wrong @Drover. I think you are getting mixed up with the specs for the Setec ST20 Series III - I one I have. Battery/ies are not connected to the loads until recharged battery voltage exceeds 11.7 volts after being slowly cranked up from a LVD of only 10.00 volts!!! In theory, a battery should not drop below the LVD as all loads connected through Setec are supposedly then disconnected from battery. However, if battery is left in this discharged condition for months after getting that low and not being recharged, that would be the end of that battery....not recoverable!!! As I have repeatedly said, once battery voltage drops below 11.80 volts, it is a fast and slippery slide to total failure. And at 10.00 volts, battery is well and truly already stuffed!!!! I work on the facts and only the facts, although I must confess that "field results" are not always as stated theoretically!

 

[Boots in Action]

Hi @Boots in Action and thank you for your welcome and reply!!

Sorry, I should have been clearer. I'm aiming for 300W in total (160W on roof + 140W solar), which sounds like the BMPro J35B can handle (no need for a MPPT controller).

How would I go about wiring the solar blanket connection into the BMPro in parallel with the roof panel? My current Solar connection is below (circled in yellow)? I am unsure how 'two connectors' can go onto the connection point (circled in yellow).

Thanks again for your time and help. Hopefully one day I can contribute to the discussion.

View attachment 66535

@RD2021 , it is quite easy really, the positive (red) and negative (black) wires from the solar panel/blanket go to the same pos and neg terminals on your PMPro as highlighted in your picture. You will probably have to use "piggy back" connectors to have both solar inputs on their individual terminals. The best and most efficient way is to have an Anderson plug on external position of van close to the BMPro. As @Drover correctly said, this will or may mean running suitable wiring through cupboards etc, but that is the tidy way and once done, never have a problem again. The wiring from external Anderson plug should have a suitable in line fuse (20A) in the positive line for safety. You must also bypass the solar controller on the solar blanket and fit an Anderson plug on the solar output wires if not already connected. If you connect the wires from the output terminals (before the controller) , you can still leave the other wires which are connected through the controller as is. You will then have two sets of wires from your panels - one set (original) still going through the controller for normal use to charge other things, and the special (new) leads (now uncontrolled) going to the Anderson plug for connection to van and inside to BMPro terminals. See below how I have positioned Anderson plug/s on side of my Penguin. For the cost of a couple of Anderson plugs, a length of suitable twin core wire (only has to carry less than 10A) an inline fuse and a bit of time, you are well ahead!
Just noticed that you already have Anderson plug and wiring going to battery terminals. Disconnect this wiring at battery terminals and reconnect both red and black wires to BMPro as above. You are even further ahead if battery is close to BMPro!!

 

[Boots in Action]

Yes @Boots in Action your probably right in regard to the LVD, I just couldn't be naffed looking it up so took a guess, I knew if it was wrong you would correct it but the rest about recharging is right and it may be lower than 12.6 but the 2 of these units I've played with both did the same thing and at the time I wanted a solution, so remove batteries, charge the things up, luckily had 2 chargers, put them back in next morning and they have played the game ever since both times faulty light switches drained the batteries with one 240 lead not truned on and the other shoddy wiring no charge..

Yes @Drover , it's me again! Did some more research again on the Operators Manual for the BMPro J35B. After very careful reading of pages 14 and 15 on the following link https://www.manualslib.com/manual/1614117/Bmpro-J35.html?page=15#manual , it appears that if voltage drops below LVD setting, the BMPro will go into "sleep" mode, or if voltage lower still, in to "storage" mode. To get out of these modes, you are supposed to start charging battery (using charger in BMPro) . No power is available to operate any van loads UNTIL unit senses there is sufficient voltage (level not stated and could be as high as you said at 12.6v!) and then all loads return to operation as BEFORE LVD disconnected loads. If voltage had dropped to 10.5v or lower, restarting from that level ("storage mode") will once again be when unit "senses" there is sufficient voltage (level not stated!) BUT this time all loads must be manually reconnected (switched OFF then ON again?) to be working again.
If a load such as faulty light switch is left drawing current (albeit only small load), for a long time , battery voltage could possibly be dragged right down to "storage" level. So all possibly happened according to the book. But once again only in theory. It makes a mockery of the statement at the bottom of page 15 which states:

"In normal use and with the J35 health preservation, batteries should never become heavily discharged". So much for theory !!!

 

[Drover]

My post got lost when I did an edit, well at 11.3 no charging happened on 2 different vans, if I recall correctly the BMPro isolated the batteries so nothing in or out, I read the book and ended up sorting it my way as didn't need stuffing around with bench top theory, first one is still going 2 years later and latest is good 6 maths or so later... don't be rude poor wiring at batteries doesn't help....
Sorry,@RD2021 Booties and I can wander off at times but rest assured just plugging your portable direct to battery won't have any great adverse effect , it does give you a fail safe if the BM craps out though when off grid.

 

[RD2021]

@Drover no need for apologies. I think you and @Boots in Action have given me a few solutions.

I basically have an anderson plug wired through to the battery. Battery sits nearby BMPro terminals. I need to check if there's an in-line fuse.

Waiting to collect solar blanket, but it seems to have a set of leads coming straight from the blanket with an anderson plug. This is supposed to connect into a regulator. Then regulator into the drawbar connection. If I understand boots correctly - I should be able to go straight from Blanket with the existing leads (no rewiring)...bypass regulator...into drawbar connection...and just replace existing battery connection onto BMPro via piggyback connections.

What a mouthful.

Again, thank you both very much. I will report back once I've tested it out

 

[MDS69]

I am with @Drover a few replies above in that use it a few times to see where you are at. Unless you have an inverter and running coffee machines and the like you will probably find you will be ok. We have 1 x 120W panel, 1 x 120Ah battery and haven’t run out of juice yet and we mostly bush camp. We have the water pump, range hood, LED lights , occasionally the 12V TV and charge the usual devices. Also run a CPAP machine through an inverter.

 

[Drover]

Also run a CPAP machine through an inverter.

Now that is a test of the system as they can be demanding buggas..............

@RD2021 , I'll take a pic later and show my fully portable solar controller, it may be a PWM unit but it can leave many so called MPPT ones behind.......

 

[RD2021]

Great, thanks @Drover

 

[Drover]

Here's my portable Solar Controller which depending how I plug my panel into the van can be put in line when plugged direct to battery or removed when the portable panel is plugged into the roof top system, it is only a PWM controller but way better than run of the mill jobs, the set up allows it to plug in to take the place of the Epever if it craps out and it will do it nearly as good as the Epever MPPT , though my Epever will suck the last grains of juice from a setting sun if need be, I like to have redundancy systems, if the wiring burns out I will be stuffed but if a unit goes down I can usually by pass, off grid means don't put the eggs in the one basket..............have included a pic of one of the most common regulators and while they get canned they do a decent job for most situations if you are set up properly, often folk aren't and if only camping for a few weeks a year doesn't make much sense to spend hundreds and hundreds of $$$ just to sit in a shed............

It should be noted that if your controller has a limit of say 500watts solar input, this applies to the actually Watts fed from the panels, if you add 500w of panels you will still have heaps of room as your panels will never reach whats on the labels...........

Heres the MorningStar with it andersons......

.

The old faithful TPS 1230, basic but does the job... soon to be running the shed 12v battery system, one day, in the fullness of time...........





Morningstar plugged into the trickle panels for shed and boat batteries, just for display purposes.......... everything has an Anderson so you can make up all sorts of connections.