Dual Solar regulator/controller?

[TravellingGuys]

Hey all,

Has anyone used this regulator or any dual battery regulator?

I have just switched one of my MPPT controllers for it today.

My current set up is 4 x 100w panels, 2 feeding a 120ah battery for tv, lights, pumps, 12v sockets and usb sockets with the other 2 panels feeding another 120ah battery for high draining items, 12v kettle, 12v stove, inverter for the water heater and fridge.

I recently installed a fan so decided to get another battery, rather than split the panels and mess on running new cables I thought I'd try a dual battery regulator but have never used one or heard how they perform.

Both my MPPT's are a great deal bigger than this, both have heat sinks on the back and both have thermistor vent but this has nothing like that which has me feeling a bit iffy lol.

It was from EBay and the seller had sold 192 prior so assume it's fine but would appreciate any input.

 

[Nabsim]

What are you trying to achieve if you already have two controllers (1 for each battery?)?

 

[TravellingGuys]

What are you trying to achieve if you already have two controllers (1 for each battery?)?

Hey Nabsim,

Previously it was 1 controller for each of my 2 batteries but after installing a fan I thought it best to get another battery so I am now running 3 batteries. I had the option of splitting the panels, running new cables and installing a 3rd regulator or the option I decided to try... have battery 2 and 3 controlled from a dual regulator.

 

[Nabsim]

You don’t need another controller, just link two of the batteries together + to + and - to -, batteries linked together are seen as a single bank so will not need a dual controller. ?

 

[TravellingGuys]

Yeah I considered that but decided against it for a few reasons:

I have always favoured having my high drain items on their own battery, that way I can monitor it, if the worst comes to worstand it gets too low due to weather not permitting a full top up then I can always do without the kettle or whatever while it replenishes.

It's always been my upstanding that you have to match up the battery ah so I'd of needed another 120ah which is a bit overkill for my needs. I've also read you should try where possible to match manufacturers etc.

The 120ah that was running has been in the van for over a year and peaks at 13.6v, the new battery was rating at 14.2v and I wasn't sure how the regulator would take it. (Maybe it wouldn't have made a difference but I wasn't sure.

 

[Nabsim]

Yes you should match the batteries, I was thinking the existing two batteries were the same just separated,, if not then not ideal. The ‘dual’ bit just means more than one bank of batteries as a bank is seen by the controller as one battery. Makes no difference if you only have one battery though. Panel sizes don’t matter so long as the controller will take the output.

I have not seen that controller before but have only seen a small number.

Wait for someone else to comment here but my understanding is you are better to increase the number of batteries in a bank rather than buy single big batteries as the recovery time is quicker but this may depend on how they are being recharged. My meds haven’t kicked in yet though so don’t take that as gospel but I can double check my source to find out if nobody corrects this ?

 

[wildebus]

You (the OP) have a very specific view on how to use your batteries and that is of course your choice.

If it were my battery and solar setup and I have "normal" and "high drain" requirements (which I do), I absolutely would not seperate my batteries for each in the way you have, to be perfectly honest.
It makes very little sense to me in practical usage terms.


You have one battery (Bat A) for normal use - lights, USB sockets. Etc.
Another battery (Bat B) for high power devices like kettle.

When you are drawing this high current from Bat B, you are pulling a high percentage of capacity from it, and the effective capacity reduces (it will not longer be considered a 120Ah Battery but a 90Ah or less).
IF you shared the load across the two batteries, then you would actually have a greater total capacity. Your 120Ah+120Ah as a single bank will be larger than two individual 120Ah + 120Ah batteries the way they are being used.
I would imagine that your light duty (Bat A) battery will be getting full from the solar panels for it a lot faster than Bat B will be, so you are not using your batteries optimally from what I can gather from your description.

Stopping using an electric kettle when Bat B is at the low point could also be achieved by stopping using the kettle when a Combined battery bank is at a slightly higher level.
You have the fridge on the battery that gets all the big hits as well - so you lose your fridge early as well?

FWIW I have a combination of standard and high current devices ... Lights, USB sockets, as usual, plus inverter for Fridge and electric blanket, plus another inverter for 2kW Induction Hob and other occasional high power items. I have my batteries configured as a single bank (4 X 110Ah AGM presented as a single 440Ah battery) with my solar configured as a single array (4 X 100W in a parallel-series setup).
This way when the hob is on I am pulling 500w (40A) per battery rather than trying to get 160A from a single 110Ah which would not be as healthy for it.
And the solar will be putting all its available energy into the entire battery store rather than wasting any due to an individual battery being full.
Think of a battery bank as a mini 12V National Grid and the Solar Panels as a central Power Generator. You are distributing power where it is needed in the most effective way instead of having local power stations, some overload and others with energy to spare.

The only circumstance I can see a reason to have a dedicated seperate battery (excluding the starter) is if you have a 'misson-critical' battery which must be available regardless of any other general usage - maybe to power a CPAP machine or similar?

As I said, I suspect you are happy with how you have it all setup and will not alter it, but for me, it makes very little practical sense

 

[maingate]

Have I got this right?

You want to change your setup because you have bought a Fan? A Fan (even a large 240 volt one) uses very little power compared to something like a Kettle.

Each to his own but I think you are making a Mountain out of a Molehill.

 

[TravellingGuys]

Cheers Nabsim, in this case the dual actually means the controller is seeing the batteries as seperate batteries, I can set 1 to have priority, charge them at the same time or not charge one if so wish.

Widebus, thanks for taking the time to type all that it's appreciated. I can see where you coming from but the way I have it is how I like it, maybe a bit ocd (which I have lol) and unnecessary/inefficient but yeah each to their own, it's served me well over the years.

I should of pointed out my whole van has been built to run from 12v, I won't go into all the detail as it will make a very long post but anything electrical in my van is 12v (other than the water heater which is from the inverter), the fridge being a cool box type.

It may not be ideally efficient but I prefer to have all my essential item, lights, pumps, chargers, tv on their own battery that way I know its never going run low. Of course you are right the low power battery is almost always full to the brim so there's 200w of power doing nothing a large percentage of the time, I've never ran flat so havent gave it much thought but you have got me scratching my head now lol maybe something I will look for next year, the batteries are at seperate ends of the van so will give it some thought. Thanks

Maingate, thanks for the reply. Yes that's me all over lol mountain out of a mole hill.

The set up I have would of most likely allowed for the fan I just didn't want to add something that may run for hours and hours a day to my high drain battery. It wasn't a major deal, I put in the new regulator, connect it to batteries and put the fan on the new battery.

 

[Nabsim]

You put it in words I couldn’t even think of at the time Dave

Batteries at different ends of the van doesn’t make it easy to connect together Max ha, ha and as you say it is doing what you want. Things don’t have to be ‘best practice’ to work or even be how you want but if folks point out what’s best at least you (or someone else) will know for reference ?

 

[TravellingGuys]

Yeah, totally agree and though I was more looking for feedback on dual regulators rather than my set up the replies and different opinions have made me rethink a few things which will likely benefit me next year so cheers.

Space is very tight now, the battery for my low drain is at the back and there's no room for another battery at the back without sacrificing something but after reading the replies what I'm going to do is...during the rest of the year is run some tests, setting the low drain regulator to 50% and seeing if 100w is enough to keep it topped up, if it is then next year I will split the panels so I have 300w instead of 200w feeding the high drain and new battery.

 

[vanmandan]

dumb question.......
with this regulator am I right in thinking the 2 left connections are for the panel,
the 2 centre connections are for the engine battery,
& the 2 right connections are for the leisure battery ???

 

[TravellingGuys]

The regulator in the pic - left connections are for the panels, the middle ones are for a leisure battery and the right connections are for a second leisure battery.

 

[vanmandan]

The regulator in the pic - left connections are for the panels, the middle ones are for a leisure battery and the right connections are for a second leisure battery.

any reason the centre connections coudn't be wired to the engine battery ??
I'd like to keep it juiced to the max.

 

[TravellingGuys]

I wouldn't of thought there would be an issue using it for that purpose, it has short circuit protection, reverse discharge protection and reverse polarity protection though I'm not certain so wouldn't like to say.

 

[Nabsim]

any reason the centre connections coudn't be wired to the engine battery ??
I'd like to keep it juiced to the max.

Check the spec for the controller you already have fitted. One of mine has a dedicated connection for starter battery that sends 1amp all the time solar is working and battery needs it.

 

[wildebus]

Yeah, totally agree and though I was more looking for feedback on dual regulators rather than my set up the replies and different opinions have made me rethink a few things which will likely benefit me next year so cheers.

Space is very tight now, the battery for my low drain is at the back and there's no room for another battery at the back without sacrificing something but after reading the replies what I'm going to do is...during the rest of the year is run some tests, setting the low drain regulator to 50% and seeing if 100w is enough to keep it topped up, if it is then next year I will split the panels so I have 300w instead of 200w feeding the high drain and new battery.

Something I have noticed recently with my fan is that when it is just 'ticking ovr' the power usage hardly registers, but when it is running at full whack, like in the current weather, it in probably the biggest current draw - easily exceeding the compressor fridge - apart from the electric Hob so it does make sense to factor it into the equation rather than just think of it as a extra little device.
Before you jump in with another battery, have you considered using this on the low-drain battery which likely has spare capacity and can likely easily support a fan in "normal" use?

 

[TravellingGuys]

Thanks Widebus,

Yeah, ideally I'd of hooked it up to my low drain but that battery is at the back and the fan had to go up front so it would of been a few metres of cabling, literally my whole roof is solar lol (another mistake I made early on, I should of put a sky light in but foolishly decided against it)

Edit: I've actually already purchased and fitted everything. I didn't mind getting the new battery, I will run some more power points from it when I get the time.

 

[TravellingGuys]

Vanmandan,

Have you ever tried one of these? (pic included) I haven't myself and they seem a bit naff but for 15 quid it might be worth a shot.

 

[wildebus]

Thanks Widebus,

Yeah, ideally I'd of hooked it up to my low drain but that battery is at the back and the fan had to go up front so it would of been a few metres of cabling, literally my whole roof is solar lol (another mistake I made early on, I should of put a sky light in but foolishly decided against it)

Edit: I've actually already purchased and fitted everything. I didn't mind getting the new battery, I will run some more power points from it when I get the time.

Yup, after my last two self-conversions having no fan and getting rather warm in the summer to say the least, the first thing that went into into the shopping basket for the current camper was a roof-fan!

Maybe a little unconventional, but something that might be worth thinking of is a way to connect the two (or even three!) batteries together with a simple relay(s) that you can switch on and off directly and 'transfer'/share power from one to another if your meters are showing lots of spare capacity on one of them? I do understand the problem as they are at opposite ends of the van, but maybe routing a cable underneath the van could actually be a fairly simple option? Often suitable bungs in the floor already you could take advantage of for this?
Doing the relay thing is not the "ideal" solution but how many people once their campervan is build (or just bought ready made) have a setup they would like to tweak one way or another but cannot due to product/furniture placement. So alternative options and ideas always come into place (I am still delaying and prevaricating the final bit of my conversion as cannot decide what to ultimately do about a bathroom/WC)

Nice choice of base vehicle BTW. I do like the Renault Masters