17' Series Battery Questions - Solar and Isolate when not in use

Duncanblake36

Active Member
Nov 17, 2016
103
168
43
Doreen
Hi Guys,
3 questions. I have the van outside and it has 2 solar panels on top of van so it keeps the batteries charged 100% all the time. One of the panels (140w) is connected to the Setec Unit that came with the van and the other (200w) is connected to a Ctec D250S charger. One solar panel is connected to one battery and one to the other. Both batteries are connected to each other using a large battery cable to make 200ah. The two batteries are 100ah but are different manufactures (done by the previous owner). Both batteries are tired and now don't last very long off the grid (as I found out on the weekend)

So my questions are:
- I looking at getting 2 x Giant Power 130ah AGM Batteries (260ah it total) Any reviews on Giant Power 130ah?
- Should I just put the two solar panels through the Ctek D250s
- Once the batteries are fully charged should I install a battery isolator so nothing is running in the van (including the solar)

What does everyone think?
 

Drover

Well-Known Member
Nov 7, 2013
12,723
19,450
113
QLD
The current set up sounds dodgy and is possibly why they don't last very long as neither battery is possibly getting charged up correctly, I would suggest reading this article https://caravanchronicles.com/guides/how-to-connect-two-batteries-in-parallel/ it will explain it far better than we can do on here.
Having both batteries connected together yet each being charged individually by seperate units is not going to work, just cause confusion to the charging units in fact the more I think about it the more I shake my head..........anyway if not connected like the article you won't be getting 100ah let alone 200ah, maybe 75.

While having batteries that are twins is ideal, it's not mandatory so long as they are the same type ie; AGM, GEL or plain old wet cell and same amperage they will work you may not in theory get every little amp but in the real world you wouldn't get there anyway, they will still work and last probably as long if you care for them properly.

You will have to set your panels up to run in parrellel and use just one regulator preferably direct to battery, depending on your setek unit you could use that but I suppose the Ctek 250s would be better though a good Mppt solar regulator would be way better, the subject has been done to death in the solar panel thread so no need to do it all again here, the thread has a lot of good info but there is a lot of chaff to wade thru....

helpful links; http://12voltblog.com.au/a-guide-to-using-solar-panels-and-regulators/

http://12voltblog.com.au/solar-panels-parallel-series-shading-diodes/ this link is a great help as it cuts out the techno bable so your eyes don't roll into the back of your head and explains the whys and where's very well and combined with the battery link you should see whats needed and why your set up sounds a bit off......
I would start off testing your current batteries as they may not be a dead as you think.
 
Last edited:
  • Like
Reactions: Duncanblake36

Duncanblake36

Active Member
Nov 17, 2016
103
168
43
Doreen
Awesome mate. Thank you. I was the same with the solar charging. I’ll get some twins and rewire the whole thing.
 

Drover

Well-Known Member
Nov 7, 2013
12,723
19,450
113
QLD
Post a pic of the batteries and their wiring so we can see how it was done, if you can........and what model setek is fitted in the van ??

If possible and you have a good multi stage charger remove each battery and charge them up properly, remove charger and come back a few hours later and see what sort of charge they have, if around the 12.6 mark then they could still be okay, no sense forking out for new batteries if not really needed.
 

SkinnyBuddah

Active Member
Jul 12, 2015
129
197
43
43
Ballarat
I'm with @Drover ... the more I read the description of the wiring and build the diagram in my head the more I shake it thinking what on earth where they doing.

Running dual batteries unless you have specific reasons as to why not (Of which use cases of an RV I can't really think of one of hand) they should be charged as they are wired... in parallel. That is Positive from charger to one battery, negative to the other. This way the pixies go through both batteries not just trying to go through the one and confusing the heck out of chargers and such in the process.
 

Duncanblake36

Active Member
Nov 17, 2016
103
168
43
Doreen
Yep - Did some internet shopping last night.
Going to rewire the whole thing so won't have any issues going forward. Going to wire all 3 panels (2 x roof and the portable) to the Ctek that way no confusion with solar charging. Wire the batteries correctly so + and - come from the separate batteries. Also the Ctek D250s has a trickle charge feature so it will keep the batteries topped up without over charging.
I'll also add a 3 way isolator switch to turn everything on, Solar only, Power only so when in storage I'll only have the solar connected.

Next trip away is Melbourne cup weekend so needs to bloody work!
 
  • Like
Reactions: Drover

Drover

Well-Known Member
Nov 7, 2013
12,723
19,450
113
QLD
Thats the way to go @Duncanblake36 , sometimes it is far easier to just start from scratch than gin around modding bits..............check the capacity of the 250s that it will handle the total of the panels as a lot of stuff just does 3 or 400w but saying that a 200w panel wont put out that much anyway also with your portable if it has its own controller then wire in an Anderson before the controller, don't remove the controller leave it set up, that way you can plug into the vans panels directly and run thru the 250s or use the panel with it's own controller to charge up an aux battery or gear not part of the van........................I bought my cable from a mob on Ebay down Melb way, 8 B&S and saved heaps though 6 B&S for the battery connection cables is better while the 8 for the panel cable and running from the battery.
 
  • Like
Reactions: Duncanblake36

geedub

Member
Aug 23, 2017
33
25
18
59
Sydney
I've had a Giant 150AH AGM for a couple of years now with no problems, it was first in my camper and now in my van. My mate has the same battery in his camper without any issues as well.
 

Duncanblake36

Active Member
Nov 17, 2016
103
168
43
Doreen
Well. Found the problem(s)...

So the previous owner put mixed an AMG and Gell Battery together! Pulled them out and was like what the hell!

Anyway. It all wired up correctly now and runs like an absolute treat.

Running 2 x 130amp AMG batteries configured like the link below.
https://caravanchronicles.files.wor...-way-to-connect-two-batteries-in-parallel.jpg

Rewired the all solar (the 140 and 250w fixed mounted on the roof and the 140 portable) to go through the Ctek D250S and now pump out 18.5amps feedin for the roof mounted ones. (the portable is used if the roof panels are in shade)

Happy now it all works - as what it should :)

AMG+Gell.JPG

2xAMG.JPG
Solar-Feedin.JPG

left.JPG

right.JPG
 

Boots in Action

Well-Known Member
Mar 13, 2017
2,054
1,806
113
Ferny Grove, Queensland
Well. Found the problem(s)...

So the previous owner put mixed an AMG and Gell Battery together! Pulled them out and was like what the hell!

Anyway. It all wired up correctly now and runs like an absolute treat.

Running 2 x 130amp AMG batteries configured like the link below.
https://caravanchronicles.files.wor...-way-to-connect-two-batteries-in-parallel.jpg

Rewired the all solar (the 140 and 250w fixed mounted on the roof and the 140 portable) to go through the Ctek D250S and now pump out 18.5amps feedin for the roof mounted ones. (the portable is used if the roof panels are in shade)

Happy now it all works - as what it should :)

View attachment 62051
View attachment 62052View attachment 62053
View attachment 62054
View attachment 62055

Hello @Duncanblake36 , some mighty fine electrical system you now have with the Ctek D250S doing all the control work to the batteries. Note that the Giant brand battery recommends 14.5 volts (at 25C) as the terminal voltage charge. Make sure you have this setting on the D250 to maximise battery charge and life. Be aware too that when you are on grid with 240 volt power, the a/c charger may not take the voltage up that high - the Setec ST20 or 35 Series III will only go to 14.0 volts. However, if any of the solar panels are receiving light and putting out some power, the SD250 controller will over-ride the setting on the 240v line and use its OWN settings as the final terminal charge voltage and possibly the float voltage too. You might like to look into this matter. I will post a thread on this using field tests obtained just recently when Daughter's van was connected to grid and had solar panels working at the same time during the day.
 
  • Like
Reactions: Duncanblake36

Boots in Action

Well-Known Member
Mar 13, 2017
2,054
1,806
113
Ferny Grove, Queensland
Its a Cetek D250S , a DC to DC charger.

Yes @Drover , I was aware of that but from what I gleaned from the technical details of this good bit of kit on computer, it is also a solar controller with "user adjustable settings" hence the post to @Duncanblake36 . I do not know what sort/type of 240v charge system he has when hooked up to the grid as this will have a bearing on things.
 

Duncanblake36

Active Member
Nov 17, 2016
103
168
43
Doreen
To charge the system on 240v is still the standard Setec Jayco system. I found that running the setec and the Ctek system together they didn’t play well together and efficiency dropped. Having everything through the Dc to Dc / solar Ctek D250s charger works a treat.
 

Drover

Well-Known Member
Nov 7, 2013
12,723
19,450
113
QLD
Yes @Drover , I was aware of that but from what I gleaned from the technical details of this good bit of kit on computer, it is also a solar controller with "user adjustable settings" hence the post to @Duncanblake36 . I do not know what sort/type of 240v charge system he has when hooked up to the grid as this will have a bearing on things.


Yeah, I reread your post and worked out that you didn't mean the D250S was 240v capable, thats why I deleted the post you quoted.
 

Boots in Action

Well-Known Member
Mar 13, 2017
2,054
1,806
113
Ferny Grove, Queensland
To charge the system on 240v is still the standard Setec Jayco system. I found that running the setec and the Ctek system together they didn’t play well together and efficiency dropped. Having everything through the Dc to Dc / solar Ctek D250s charger works a treat.

Yes @Duncanblake36 , I had a funny feeling that that might happen with your very sophisticated DC to DC operation with the D250s conflicting with a pretty rudimentary charger like the standard Setec provided in the Jayco. Its the old story of conflict between two devices with different settings - like two solar controllers on the same battery! Having it all through the one controller that does it all is definitely the way to go.
 

Drover

Well-Known Member
Nov 7, 2013
12,723
19,450
113
QLD
I must get myself one of those Watt meters, been on the To Do List for a few years now................
 
Last edited:

mikerezny

Well-Known Member
Sep 11, 2016
1,630
2,728
113
Mount Waverley, VIC
Last edited: