What solar controller?

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
Hi,

We are currently living in our motorhome for about the next year as we are travelling. The solar is essential for charging the batteries and at the moment the controller doesn't seem to be doing the best job. So maybe it needs replacing but which one should we get?

Set up
Hymer B774
2 panels on roof (no further knowledge)
'SunWorks' DB2C solar controller
3x 100(110?)ah Numax batteries
1x 90ah Varta engine battery

Panels - appear to be working fine - we are getting up to 8.5a in Spain/France in February.

SunWorks controller - instructions are only one page. On 'boost' or 'P' mode it seems to charge well. However on Float or Winter mode it does very little. Most mornings it goes into float or winter. If we go in a tunnel it resets to boost.

Batteries - a few years old as far as I know. Doing the job but discharging faster than I would expect. They are lasting two nights if it isn't sunny with heating fan, led lighting, water pump, charging two phones/occasionally a tablet. Normally our load doesn't exceed 5A with heating running at full pelt. By lasting I mean on the second morning the heating cannot run on fast fan or will cut out if you turn a tap on. The reading will be around 11.9V. Fully charged the controller reads somewhere around 13.7. Once we start putting a load on it drops to 12.8 then soon 12.4 and it stays around there. Pretty much always 12-12.2 in the morning then solar charges up to about 12.6 in the day if not really sunny.
Engine battery is fine.

Our solar runs direct to batteries and doesn't go through the electroblock (EBL100) or the Hymer control panel (DT200).

Driving charges the batteries to some extent but cannot fully charge them in a couple of hours, it takes more like 4 hours + solar.

My husband is trying to read up about this but it is confusing so thought I would ask here for help.

Possible replacements we have looked at:
Victron MPPT - like for like replacement. £110ish Can this only work on one battery though? Has Bluetooth app display/settings. Supposed to be good in low light.
Schaudt LRM1218 - wiring up through the electroblock. More complicated? Expensive £200+
Votronic MPPT250 - like for like replacement, dual battery. No display (we would need to buy separately as our EBL isn't compatible)

Priorities:
Charging batteries! Esp in more northerly areas (UK, Ireland, Scotland, Scandinavia)
The cheaper the better
Easy to fit (DIY)
Able to get this week as we are only in England for a week.

Any advice please?

Thanks,
Moose :)
 
Last edited:

funflair

LIFE MEMBER
Dec 11, 2013
15,241
20,145
Guisborough
Funster No
29,351
MH
MORELO palace
Exp
since 2012
We have had the Votronic MPPT duo fitted for about 4 years now and it just gets on with doing what it is supposed to do. Are you convinced that your batteries are OK, do they last any longer if you give it all a good charge from EHU.

Actually we have two Votronic controllers fitted 1 controlling 1 panel and the other with 3 panels, and I know the batteries are coming up to float charge when one of the controllers goes to sleep as the remaining one can handle the charge.

Martin

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
. Are you convinced that your batteries are OK, do they last any longer if you give it all a good charge from EHU

No, we don't know if the batteries are ok. After an EHU charge they last longer, maybe 3 nights? It is hard to tell as the solar is always on and charging in the daytime and the weather and our driving distance is so variable!
We are suspicious that something isn't right though as we have to either have strong sun, a 4 hour drive or EHU every 2 days and we were expecting more from this set up (2 panels, 3 leisure batteries).
Replacing batteries and/or solar controller is ok, just money is tight and we have 5 tyres (hopefully not all 7) to replace this week too so we don't want to waste money replacing something that isn't an issue!
 
Jan 19, 2014
4,577
14,043
south shields
Funster No
29,767
MH
Chausson 620 welcoome
Exp
since 1990
hi moose , ive read nothing in your post that indicates you need a new controller,
you say the panels are working, giving 8.5 a, so it follows that your controller is fine and doing its job...
its unlikely you will get a great deal more changing your controller without increasing your panel wattage...
Andy

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
We have had the Votronic MPPT duo ...
Actually we have two Votronic controllers fitted 1 controlling 1 panel and the other with 3 panels, and I know the batteries are coming up to float charge when one of the controllers goes to sleep as the remaining one can handle the charge

Is this with or without the display unit? As that is an extra £70+£20 mount that we could maybe do without. We can see the battery voltage on the Hymer control panel, just not the changing amps.
 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
hi moose , ive read nothing in your post that indicates you need a new controller,
you say the panels are working, giving 8.5 a, so it follows that your controller is fine and doing its job...
its unlikely you will get a great deal more changing your controller without increasing your panel wattage...
Andy
We aren't trying to increase the amps, we are trying to increase how much of that goes into the batteries. The controller we have keeps using restricting modes (float and winter) that restrict how much goes into the battery. It is daft when it might be full sun outside and low batteries but it just stays in float mode all day, never in boost or 'P' which are the 'proper' charging modes.
 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
Our controller has no controls, not even an on/off switch. We contacted the manufacturers and they sent us the single page instructions. There are no settings we can change.

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
This could be a battery problem or controller problem (or both!) but we don't know how to tell which is the problem. But controller getting stuck on float indicates there is an issue or bad design there. The batteries are a few years old and have been on constant solar in that time, including Morocco etc by previous owners for a few months at a time. So they might be getting old?
 
Jan 19, 2014
4,577
14,043
south shields
Funster No
29,767
MH
Chausson 620 welcoome
Exp
since 1990
We aren't trying to increase the amps, we are trying to increase how much of that goes into the batteries. The controller we have keeps using restricting modes (float and winter) that restrict how much goes into the battery. It is daft when it might be full sun outside and low batteries but it just stays in float mode all day, never in boost or 'P' which are the 'proper' charging modes.
I get you now , sorry..
and the mode is selected automatically by the controller I assume..
in that case as long as you are sure the batteries are in a discharged state then you would expect it to run in boost mode...
have you tried rebooting it to see if that makes any difference
Andy
 

funflair

LIFE MEMBER
Dec 11, 2013
15,241
20,145
Guisborough
Funster No
29,351
MH
MORELO palace
Exp
since 2012
Is this with or without the display unit? As that is an extra £70+£20 mount that we could maybe do without. We can see the battery voltage on the Hymer control panel, just not the changing amps.
Yes we have the "solar computer" which just plugs into the controller and gives you a remote readout of Volts Amps and Watts as well as a cumulative total which you can reset daily if you wish.

Martin

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
I get you now , sorry..
and the mode is selected automatically by the controller I assume..
in that case as long as you are sure the batteries are in a discharged state then you would expect it to run in boost mode...
have you tried rebooting it to see if that makes any difference
Andy
Absolutely no controls on the controller so can't even reboot. We have just searched out the fuse (10A fuse on a 15A controller :confused:) so will take that out and back in tomorrow to reboot it, see if that helps.

EDIT: That won't work as it is powered from the batteries d'oh!
 
Jan 19, 2014
4,577
14,043
south shields
Funster No
29,767
MH
Chausson 620 welcoome
Exp
since 1990
Absolutely no controls on the controller so can't even reboot. We have just searched out the fuse (10A fuse on a 15A controller :confused:) so will take that out and back in tomorrow to reboot it, see if that helps.

EDIT: That won't work as it is powered from the batteries d'oh!
I was thinking just disconnect the batteries and the panels, keeping the bare wires well protected...
then reconnect the batteries first, then the panels, see how that goes..
just leave it a few mins before reconnecting..
Andy

Subscribers  do not see these advertisements

 

funflair

LIFE MEMBER
Dec 11, 2013
15,241
20,145
Guisborough
Funster No
29,351
MH
MORELO palace
Exp
since 2012
Absolutely no controls on the controller so can't even reboot. We have just searched out the fuse (10A fuse on a 15A controller :confused:) so will take that out and back in tomorrow to reboot it, see if that helps.

EDIT: That won't work as it is powered from the batteries d'oh!
There should be a fuse close to the batteries, it might be worth disconnecting the panels at night (or cover them) and then disconnect and reconnect the controller to the the batteries and then reconnect the panels to the controller.

Martin

EDIT fastfingers Andy got there first(y)
 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
@DBK We think the batteries are low as the electricity supply starts being problematic (eg turn a tap on and the water pump running stops the heating fan running. Or makes the lights flicker). At this stage the controller is reading 11.8-12.1V.

In my terminology:

'Not fully charged' is for instance showing 12.4-12.6V on battery once too dark to charge but before we start putting any load on it.

'Fully charged' is 12.8 upwards in the dark before any load.

If any of these numbers are wrong do let me know, I am learning as I go along.
 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
So Plan Step 1 is to reboot our controller, see if it is more sensible. It might take a few days to tell as it varies whether it starts the morning in boost or float.

Step 2 - we have a trickle charger in the UK which is supposed to rescue (desulphate) batteries. Is it worth putting each battery through this to see if it improves?
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
32,272
60,484
On the coast in West Sussex
Funster No
658
MH
Hymer B678 Dynamic Line
Exp
Since 2008 & many years tugging
Sounds to me like your batteries have had it. With the solar output you have and your batteries you should be able to survive in Spain indefinitely not just a couple of days.

See how things go once you have replaced the batteries, if you decide on a new controller the Votronic is compatible with the EBL and they sell a set of cables so it just plugs into the EBL.
 

DBK

LIFE MEMBER
Jan 9, 2013
16,346
38,343
Plympton, Devon
Funster No
24,219
MH
PVC, Murvi Morocco
Exp
2013
@DBK We think the batteries are low as the electricity supply starts being problematic (eg turn a tap on and the water pump running stops the heating fan running. Or makes the lights flicker). At this stage the controller is reading 11.8-12.1V.

In my terminology:

'Not fully charged' is for instance showing 12.4-12.6V on battery once too dark to charge but before we start putting any load on it.

'Fully charged' is 12.8 upwards in the dark before any load.

If any of these numbers are wrong do let me know, I am learning as I go along.
I think the others have beaten me to it because the symptoms suggest dead batteries. After a day of sun you should be seeing something around 13.8 volts in my experience.

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
If we are getting new batteries then I presume going for Varta 90ah is the best option as they are readily available and better quality than what we have at the moment. Is that correct?

Need to decide whether to get 2 or 3 though. We aren't going to be any further south than Ireland in the next 4 months and are planning a couple of months in Norway, mainly wild camping/Aires so need reliable solar and batteries.

I see Varta also do bigger batteries but they weigh a lot (eg 56kg!) so could be tricky to actually lift into the locker so a couple of normal size might be better than a huge one?
 

DBK

LIFE MEMBER
Jan 9, 2013
16,346
38,343
Plympton, Devon
Funster No
24,219
MH
PVC, Murvi Morocco
Exp
2013
Varta LFD90s are what I've got. If you can fit 3 go for it but another battery just means you can last another day or so. You need sun for stamina . :)
 

Bobby22

Free Member
Dec 15, 2013
1,537
6,413
Scotland
Funster No
29,386
MH
Rapido 680ff
Exp
since 2013
Have you checked that your solar panels are clean. If your solar panels are covered in grime or algae you may not be getting all that may be available.ie. taking out more than being put in.

Just a thought.

I have 120w solar and basic controller 2x 110amp batteries and can get 5 days in winter in Scotland static.

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
Have you checked that your solar panels are clean. If your solar panels are covered in grime or algae you may not be getting all that may be available.ie. taking out more than being put in.

Just a thought.

I have 120w solar and basic controller 2x 110amp batteries and can get 5 days in winter in Scotland static.

Yes, panels are clean, I washed them recently. Thank you for your numbers, it helps me know what is possible.
 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
Well this morning has shown our batteries are dying. Yesterday we were fully charged on EHU, then drove for 4 hours. Batteries reading 14.1 while driving, solar controller turned itself off, batteries at 13.8 once parked for the night. This morning they are at 11.8v, heating cutting out when we turn on a tap...
300Ah batteries shouldn't run out in just one night when our load is maximum 5A an hour!

Subscribers  do not see these advertisements

 
OP
Randommoose

Randommoose

Free Member
Sep 17, 2017
190
187
Funster No
50,578
Varta LFD90s are what I've got. If you can fit 3 go for it but another battery just means you can last another day or so. You need sun for stamina . :)
We've got plenty of space and payload and currently have 3 in a locker. Will measure to see whether a big one would fit or not and find out what the shop has in stock.

Yeah can't do much without sun. Hopefully with a decent battery bank then we can last a few days of a full charge (whether sun or ehu) with bits of top up from solar. Our solar does charge in cloud and rain which surprised me.
 
Jan 19, 2014
6,765
16,715
Derbyshire
Funster No
29,757
MH
Elddis Accordo 105
Exp
since 2014
We've only got one 100ah battery and it lasts us indefinitely with the 150w solar. Remember the battery only needs the capacity to last you from sunset to sunrise, shortly after sunrise the panel is whacking 8a back in in summer.
 

funflair

LIFE MEMBER
Dec 11, 2013
15,241
20,145
Guisborough
Funster No
29,351
MH
MORELO palace
Exp
since 2012
We've only got one 100ah battery and it lasts us indefinitely with the 150w solar. Remember the battery only needs the capacity to last you from sunset to sunrise, shortly after sunrise the panel is whacking 8a back in in summer.
And on a grey day? possibly 1 amp, thats where extra capacity comes in.

Martin

Subscribers  do not see these advertisements

 
Top