Using solar suitcase to augment rooftop panels
- Thread starter mayble
- Start date
Help Support Van Living Forum:
highdesertranger
R.I.P HDR
- Joined
- Apr 4, 2012
- Messages
- 22,892
- Reaction score
- 89
the charge controllers do not need to be linked. on mine I have permanent and portables and run them all through the same controller. but my portables do not have a dedicated controller. highdesertranger
1 don't put the same panels to different controllers
2 OK to put multiple panels to one controller, as long as within specs and ideally matching, if not at least matching voltages.
3 OK to put multiple controllers to one battery bank, ideally same charging setpoints.
Most efficient is a setup designed to coordinate them, but no harm otherwise.
Trimetric bank monitor controlling 2x SC-2030s, for a total output of 62A, is IMO ideal good value for a medium size setup, large for most mobile but <900w actual output
2 OK to put multiple panels to one controller, as long as within specs and ideally matching, if not at least matching voltages.
3 OK to put multiple controllers to one battery bank, ideally same charging setpoints.
Most efficient is a setup designed to coordinate them, but no harm otherwise.
Trimetric bank monitor controlling 2x SC-2030s, for a total output of 62A, is IMO ideal good value for a medium size setup, large for most mobile but <900w actual output
thanks for your input - just want to clarify
if i have say 300 watts of solar on the roof feeding one charge controller, i can still simply hook my solar suitcase (with its built-in controller) to the same battery? the charge controllers won't interfere with each other? in my web searches i've found some people insist that one controller will read the input of the other charging source as a full battery and stop charging; others say that isn't an issue.
i just want to be able to use the suitcase for additional juice (if i'm parked in the shade for example). i have a 100w renogy eclipse suitcase. the van is still naked at this point. simplicity and flexibility are key.
if i have say 300 watts of solar on the roof feeding one charge controller, i can still simply hook my solar suitcase (with its built-in controller) to the same battery? the charge controllers won't interfere with each other? in my web searches i've found some people insist that one controller will read the input of the other charging source as a full battery and stop charging; others say that isn't an issue.
i just want to be able to use the suitcase for additional juice (if i'm parked in the shade for example). i have a 100w renogy eclipse suitcase. the van is still naked at this point. simplicity and flexibility are key.
SternWake
Well-known member
- Joined
- Nov 30, 2013
- Messages
- 3,874
- Reaction score
- 2
mayble said:
Yes, you can hook to same battery terminals. i would not use a shared (+) Buss for both controllers but hook right to battery terminals if possible/convenient.
B. When the battery gets upto absorption voltage, well one controller's ABSV might be higher than the other. the one with the lower ABSV will stop producing current as the voltage is higher than it wants to see.
Usually at this point the output of the extra solar is not required anyway. There can be some weirdness when one controller first drops out and the other panels alone cannot produce enough amps on its own to maintain absorption voltage voltage would drop and the other controller would kick back in, then drop out again.
Even if set to the same absorption voltage there can be weirdness at that threshold, but it should not affect overall time to recharge by more than a few minutes. How any specific controller reacts tpo the presence of another controller when the battery is up at the absorption voltage threshold is an unknown until one witnesses the behavior when it occurs.
no worries of damage to either controller though.
What would happen is one controller would try and revert to float voltage. I'd program, if possible, the portable's controller to a float voltage same as Absorption voltage and a tenth lower than the main solar controller if those few minutes are stressing one out
It really depends on the charge controller you are useing, so read the book. Generally. Two controllers from two different solar banks. Whichever solar bank has the highest output will charge the battery. Such as if one bank is in the shade and one is in the full sun. Why would it make a difference if connected to the buss bar or directly to the battery, I have no idea.
Weight said:
No, parallel charge sources's amps are additive, it isn't either-or, the voltage gets muddled if they're different is all.
Just inefficient if not robust enough.Weight said:
Separate voltage and temp sense wires should definitely be direct though.
SternWake
Well-known member
- Joined
- Nov 30, 2013
- Messages
- 3,874
- Reaction score
- 2
If there are two solar controllers, Ideal would be each wired to battery terminals instead of a Buss at some distance/resistance from battery.
This will likely mitigate the Absorption voltage yoyo effect when the battery first reaches the absorption voltage with both charging sources having got the battery up there.
How much better/ more effective the controllers will be directly to battery terminals rather than a shared buss some distance away, is unknown without observation of all parameters. Easier to just try and ensure closest to ideal, rather than worrying if 'just fine', really is, or finding out is is not, and now requires more effort than if one had taken the extra step initially.
When my adjustable voltage power supply AND my solar get the battery to 14.7v where I have then set, I can hear the overvoltage protections on my Meanwell kick off and on. If I raise meanwell voltage to 14.8v, then solar controller kicks off, IF I lower Meanwell voltage to 14.6, then IF the solar can produce enough amperage to maintain 14.7v on its own, then the meanwell shuts off and drops out.
but have them both set exactly and the clicking of the meanwell's overvoltage protections on and off is annoying and I know it is time to unplug i as the solar can finish off the job from there on its own.
Mine do share the Unideal Buss on the battery switch and the Shunt, It just has to be that way. But the Busses have thick cabling going to them.
Thick copper and good cable/wire terminations can often mitigate 'less than ideal' and often is the only way to do so.
This will likely mitigate the Absorption voltage yoyo effect when the battery first reaches the absorption voltage with both charging sources having got the battery up there.
How much better/ more effective the controllers will be directly to battery terminals rather than a shared buss some distance away, is unknown without observation of all parameters. Easier to just try and ensure closest to ideal, rather than worrying if 'just fine', really is, or finding out is is not, and now requires more effort than if one had taken the extra step initially.
When my adjustable voltage power supply AND my solar get the battery to 14.7v where I have then set, I can hear the overvoltage protections on my Meanwell kick off and on. If I raise meanwell voltage to 14.8v, then solar controller kicks off, IF I lower Meanwell voltage to 14.6, then IF the solar can produce enough amperage to maintain 14.7v on its own, then the meanwell shuts off and drops out.
but have them both set exactly and the clicking of the meanwell's overvoltage protections on and off is annoying and I know it is time to unplug i as the solar can finish off the job from there on its own.
Mine do share the Unideal Buss on the battery switch and the Shunt, It just has to be that way. But the Busses have thick cabling going to them.
Thick copper and good cable/wire terminations can often mitigate 'less than ideal' and often is the only way to do so.
WalkaboutTed
Well-known member
- Joined
- Dec 18, 2016
- Messages
- 910
- Reaction score
- 3
We have 445 watts rooftop solar going through a Blue Sky 3000i. Our 100 watt suitcase solar will be attached through our Ctek d250s, which also works as a dc to dc charger from the engine. The nice thing about the Ctek is that if the aux battery bank is fully charged, the Ctek will take the extra solar and charge the engine battery.
We originally planned the 100 watts only, but it got away from us and we ended up putting on as much paneling as we could reasonably carry. I don't think we'll regret that much power.
Ted
We originally planned the 100 watts only, but it got away from us and we ended up putting on as much paneling as we could reasonably carry. I don't think we'll regret that much power.
Ted
mayble said:
I have both roof and suitcase solar, it works perfectly. I have both controllers set to the same bulk, absorb, float. Prior to that I had a different suitcase controller that I did not set the bulk, absorb, float, just left it at default (14.4v I think) it still worked just fine, just one controller would shut off before the other, not as good, but still worked fine.
I've heard from multiple sources the solar piece is not great on those. When you get the chance, try an A/B test moving it to the real controller and compare watts output to battery.WalkaboutTed said:
And let us know, those CTEK DCDC are otherwise nice units.
WalkaboutTed
Well-known member
- Joined
- Dec 18, 2016
- Messages
- 910
- Reaction score
- 3
Yeah, the presets on the ctek aren't the optimum, but I bought it before I was educated by all of you fine people on CRVL here. Since it's just the portable on it, though, I'm okay with "good enough". I consider it, if not an overabundance of power, "gravy" energy, just with a couple of lumps.
Ted
Ted
WalkaboutTed
Well-known member
- Joined
- Dec 18, 2016
- Messages
- 910
- Reaction score
- 3
John, that's an intriguing question. I'll do that next time I have the portable unit out and hooked up. I just had it out a couple of weeks ago, when I checked to make sure everything is working with the ctek. . But right now I don't need to use it at all since all we're running is the built-in fridge and overhead fan (24/7 because of the heat here in AZ) and the roof-mounted solar handles all of that and more. I'm a lazy bones.
Ted
Ted
