MPPT & Starter Trickle

My leisure bank do not connect to chassis, I just run the single wire from the Votronic to the positive starter lead coming to/from my main control unit. In my case it is an EBL but can’t see it would make any difference.
Edit: just to add, that’s how Votronic show to do it. Do you have the data sheet for the unit as I can send if not, it’s the same as my 250
 
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nickvanbitz said:
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We manufacturered Battery Master years ago, where it would combat vans that are parked up for durations, unused, with the van either plugged in, using a solar panel, or even simply sat there with an unused Leisure Battery as a resource of back-up power. At the moment, we average about 20-30 units supplying to dealers alone, not including our own fitting here.
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I didn't realise just how much the additional engine battery drain would be on my x290 van when I replaced my 2005 camper.

JohnsCrossMotorhomes, my local dealer, recommended your Battery Master and I had one fitted. It's solved all the issues at a stroke, so from a happy customer........ Thank You.
 
@nabsim
Thanks for the offer but I've already downloaded the installation instructions - screenshot below.
I see what you mean about the EBL terminal reference.

I think I'm now more confused though - when I got the van original solar spliced into leisure battery main wires near PSU - which I replicated with new dual and then added twin wire direct to starter (no change out of 10m lead!).
As far as I can make out there's no direct connection between starter and leisure batteries. I think the leisure gets alternator change via ECU200 when that disconnects the habitation 12v on engine start.
If I had a VSR presumably I'd expect to see fairly substantial cables going from leisure forwards to engine bay?

The instructions show grounded leisure - without that i dont see a simple return for starter charge.
Are you saying that if I find the positive starter connection from my PSU and splice into it that somehow the negative gets hooked up?
Or would it be easier to effect negative continuity by just connecting battery negatives together at controller?
 

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Markd said:
@nabsim
Thanks for the offer but I've already downloaded the installation instructions - screenshot below.
I see what you mean about the EBL terminal reference.

I think I'm now more confused though - when I got the van original solar spliced into leisure battery main wires near PSU - which I replicated with new dual and then added twin wire direct to starter (no change out of 10m lead!).
As far as I can make out there's no direct connection between starter and leisure batteries. I think the leisure gets alternator change via ECU200 when that disconnects the habitation 12v on engine start.
If I had a VSR presumably I'd expect to see fairly substantial cables going from leisure forwards to engine bay?

The instructions show grounded leisure - without that i dont see a simple return for starter charge.
Are you saying that if I find the positive starter connection from my PSU and splice into it that somehow the negative gets hooked up?
Or would it be easier to effect negative continuity by just connecting battery negatives together at controller?
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Yes, that’s how mine is. My mains chargers go through my EBL and it all under the same seat as my B2B (Votronic), solar controller and leisure bank. The solar controller runs two cables, (+ and -) to the leisure bank and a single positive to the positive cable going to the starter battery from mains charger in effect.

Your diagram shows the single cable going to the starter, I picked it up close by. it is only a 1amp trickle charge to starter battery so lack of big cables shouldn’t hurt and if you have mains charger it should be big enough for a lot more than that, probably at least 16amp (mine has two 18 amp chargers but I added the second plug and play to EBL).

Edit: I didn’t get any manuals with my van so can’t be 100% certain there isn’t a negative somewhere between both banks. If you put a meter on starter when you are harvesting it should prove it one way or the other for you though.
 
Thanks.
Good point about picking up the starter charge near PSU to get a decent capacity.
My current charger in theory could go 100% to starter, my flex is way too small for that (it is fused) but I don't expect that to happen because solar is always connected and battery should be full when I stop driving

Like you I don't have any original meaningful circuit diagrams.
Sargent stuff is just pictorial.
Bessacarr is a bit better but shows Sargent as black boxes!

I'll have a rummage to see what I can find before I buy and as you say I could just connect single wire and see what happens.
It's just that the epever controller is straightforward with two connections per battery.
 
Depends on what vehicle you have, but if all you need to do is connect a trickle charge output to the starter battery you can use just about any circuit you can find that is powered by the starter battery and avoid running a line all the way back to the battery if that was what you had planned. That 1A additional load will make no difference to the circuit.
With many other vehicles you could even tap into the orginal interior lighting circuit +12V line for the trickle connection as the +12V is permanently live regardless of any courtesy light switch controls.
 
Thanks but I've already run a dedicated twin flex from solar at rear to engine bay - not much coiled up from 10m!
I've got a Bessacarr E745 and to fair to them most of the wiring is well concealed but there's a mass of leads coming out o the Power Supply Unit.
So rather struggle with a work round I just ran a lead through the wardrobe floor and along the chassis.
 
I've found a full wiring diagram in a handbook with good colour coding.
Apparently I should have leisure battery ground to chassis - so I'll do a physical check - update I couldn't see it directly but the neutral cable runs round the whole van in the same colour and eventually goes back to starter battery. So I do have a grounded leisure battery.
The split charge relay is shown as two alternator triggered relays which must be the large flat high current "array" on top of starter battery.
I'm now confident that I can use the single wire trickle charge connection on the Votronic 😀
Whilst rummaging around the solar controller I found that I'd managed to set the charge priority round the wrong way so the leisure was 10% if demand from both batteries.🙁
Most of the time probably didn't make that much difference because when one battery is charged all power goes to the other.

Thanks everyone for your help and patience in getting me to understand my system.
 
Markd said:
Thanks for the idea but I reckon I'll be getting a 2 channel charger.
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Yep I would have done the same if I had discovered the voltronic range before I bought my kit.

something else to consider I have a very dim view of split charge relays and I am 100% in the b2b camp a lot of b2b controllers include mppt and some include a trickle functionality

E.g. I am waiting on one from Renogy to arrive the DCC50S to evaluate in a clients van
 
CriftinsCampers said:
Yep I would have done the same if I had discovered the voltronic range before I bought my kit.

something else to consider I have a very dim view of split charge relays and I am 100% in the b2b camp a lot of b2b controllers include mppt and some include a trickle functionality

E.g. I am waiting on one from Renogy to arrive the DCC50S to evaluate in a clients van
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you need to be careful of the Combo B2B/MPPT Controllers. They work well and are usually very good value compared to separate units but .... the Solar Side has limits. You will never be able to run multiple panels in series for example. And bigger arrays are not possible.
 
The only reservation with a dual charge regulator, is this is all dependent on mother nature putting power in both batteries. At least with a stand alone Battery Master/Maintainer, you have the benefits if Hook-up is there, or even in a dire situations of no charge input, then such a device will use the untapped Leisure Batteries as a back-up. Some Dual units will only engage at a certain Leisure Battery level too, where as an external device will react based on the difference between the Leisure and Engine Battery Voltage.
 
Yes some do have limited max Vcc the worst being the feeble ctek ds250 at 23v I was considering the abso that supports up to 45v but it‘s got some unpleasant out if the box features like a 3 minute delay before disconnecting from the chassis battery, not ideal if it is pulling the full 50A at the time.

the Renogy i think is an ideal budget unit for it’s price especially with a discount at under £200 it‘s a 50A b2b and supports up to 600w of solar albeit as you said via smaller panels wired in parallel plus it offers trickle charging to the chassis.

I won’t know if it’s any good till I have tested it especially in this grey weather but the ring rscdc30 it will be replacing has done very well for a relatively cheap thing.
 
@nickvanbitz Good points.
My mains hook up includes a charger for both batteries.
We don't often stay long in the same place so I'm not overly concerned about starter drain.
But as I did initially completely flatten the starter battery during a long period out of use I want to ensure it stays topped up.
I note the possibility of leisure priority and if I end up without enough starter power I guess we'll just have to enjoy our stay a little while longer 😀 or call breakdown if we're in a rush.
In our van you can't just leave sidelights on so not overly worried.
 
nickvanbitz said:
The only reservation with a dual charge regulator, is this is all dependent on mother nature putting power in both batteries. At least with a stand alone Battery Master/Maintainer, you have the benefits if Hook-up is there, or even in a dire situations of no charge input, then such a device will use the untapped Leisure Batteries as a back-up. Some Dual units will only engage at a certain Leisure Battery level too, where as an external device will react based on the difference between the Leisure and Engine Battery Voltage.
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Don’t confuse the two I.e. mppt vsr b2b Etc with mains charging, all can work independently alongside each other, I have the full house in my Ambulance 3x 250 split charge relays which are presently redundant, 2x mains battery chargers, one high current the other a ctek mxs5 as a maintainer for when the vans out of the sun under my carport, 2x B2B and a Mppt tracker they all work quite happily alongside each other. As of now solars maintaining everything.
 
What I think the original OP is trying to do is to maintain his engine battery from available resources (Solar/Mains/Leisure Batteries). He may already have a very good B2B/DC-DC/Split Charge system in place already.

@Markd, rather than having to swap out a perfectly good working regulator you've already spent out on, I'd be looking at a retro fit Battery Maintainer either ours or someone else's. Then you won't have to panic too much where the resource of charge comes from to support the engine battery.
 
My starting point is to go MPPT to optimise my existing panel particularly at this time of year but I do want to continue having peace of mind 're starter battery.
As it happens my PWM controller was provided free by the outfit I bought the van from but is only c£30 to buy.
My system is pretty basic and I'm just looking for a good value upgrade which Votronic 165 seems to offer.
 
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Markd said:
My starting point is to go MPPT to optimise my existing panel, but I do want to continue having peace of mind 're starter battery.
My system is very basic and I'm just looking for a good value upgrade which Votronic 165 seems to offer.
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Do bear in mind the Votronic will not provide any trickle charge to the starter battery WITHOUT solar input so may not give you as much peace of mind as you wish?
 
That's true - however since I put the dual charger in 3 years ago I've not had a problem with starting after storage.
Am I on wrong track with going MPPT?
 
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