Solar Panel Isolation

So to get back to original query.Switch, if i decide to fit goes between panel and controller. Not as Andy in post 9 seems to indicate between controller and battery or am i reading that post wrong??
 
poppycamper said:
So to get back to original query.Switch, if i decide to fit goes between panel and controller. Not as Andy in post 9 seems to indicate between controller and battery or am i reading that post wrong??
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My original reply to your question was given in post #3?
I'm sorry if I've taken it a bit off topic??
Andy
Edit.. I've just looked ..post 9 was a reply to Mel.. It is usually a recommendation to fuse the output on a solar controller.. That's still relevant..whether you choose to have isolation on the panel side...which isn't generally necessary..other than convenient at times...
Andy
 
Andy no need to apologise... off topic was very informative and I did not click that you also wrote post 3. Just reread 9 and it now does make sense. Thnx
 
Sorry to keep going on but can someone please explain the settings on my controller.
It states in lithium mode it has "U2 full/trickle/storage charging 13.??v continuous. Does this not mean continuous trickle charging

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You can fully charge a Lfp at 3.4vpc aka 13,6v given a enough time, like the van sitting idle with no loads.
The voltage cut off given by manufacturer at 14,2- 14,4v are when you charge with a stable rate of 0,2C.
That’s a constant 20A for a 100ah battery. Do you meet that requirement? When your charging is opportunistic and NOT constant, (solar), your voltage cut off should be no higher than 13,6v if you DON’T want to charge to 100%. You should not rely on bms for everyday cycling. Is there as a fail safe And should not be used as a regulator.
Dial intonyour controller conservative voltage limits, and you get good life of the battery.
 

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If you float charge at 13,4v that’s ok, it will not put any energy in the battery, but it will supply the loads from solar, and not cycle the battery. Any higher than 13,48-13,50v it will float charge. All depends of the total loads you got during charging.
I set mine on 13,45v float (got loads to feed), and 13,65 absorb for 30mins. All set on victron controller. I don’t use the victron Lfp setting profile as for me is to high at 14,2v absorb and 13,8v float. That forces the battery to 100% charge fi toooo long. The longer you sit at high voltage, the more degradation occurs.
 
Raul.. Glad u did second post cause first went straight past me. But I get jist now. It gives 14.2/4/6v depending on settings to charge then drops to 13.??v again depending on setting. At least i think that's what you are saying
 
If float is at 13v that is way to low. It will cycle way to deep before it triggers the charger to pump in again.
You need a float of at least 13.4v to sustain loads. If no loads then no problem.
 
Sorry Raul.. did not put that very well. Settings are
U1 13.9v. U2 13.9v
14.2v. 13.6v
14.4v. 13.8v
14.6v. 13.6v
14.8v. 13.65v
So as all these U2 figures are above 13 .4v does that mean there will always be a trickle charge?

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Hi not able to afford Lithium not sure if this is the right thread to bring this up but been going though a similar dilemma so looking at AGM or Gell any comments please would be greatly received thanks
 
Thanks for your time and effort Lenny which is really appreciated And i saw those graphs in the instruction booklet. Give me an engine.. fuel injector.. carberator or anything mechanical then I your man. BUT they really don't mean a thing to me.. I have tried to make sense of them but couldn't so that is why I asked on here.
 
poppycamper said:
Sorry Raul.. did not put that very well. Settings are
U1 13.9v. U2 13.9v
14.2v. 13.6v
14.4v. 13.8v
14.6v. 13.6v
14.8v. 13.65v
So as all these U2 figures are above 13 .4v does that mean there will always be a trickle charge?
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Yes it will. The less aggressive out of all will be the 14,2v - 13,6v combination. If you can set a 0 time for absorb, and have some draw while charging, the 13,6v is not to bad, providing your solar yield will not exceed to much your loads.
The victron charger has user defined settings, where you can set time for absorb as well. A charger that has fixed default time, is just a work around from Lead.
At 14v and up will trigger cell balancing, and will hold at high voltage the cells that are charged, till the others are catching up. This is what degrades them, add some temp in the mix and the state of health will dive.
From 13,6v to 14,4v is less than 10% energy, that is not worth it. Same for the bottom knee. At 12.4 should be the cut off with a pre alarm at 12,5v.
Below this is going to dive fast as is little energy left that’s not worth discharging. If you do, the bms will disconnect and will leave your charger without battery but solar connected. That is bad for the charger.

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Don't think my roof would take the weight of a generator??
 
I have the Votronic Duo Digital too. It's a good controller. I put a circuit breaker between panels and controller (inside as close to panels as possible) and a fuse in the positive between controller and battery (close to battery).

The circuit breaker is handy if I want to do work on the system or read the battery voltage without the solar charge confusing the reading. I have read from a knowledgable source those type of circuit breakers are not very good quality - made from rubbish materials and trip out of spec. He prefers to use a big fuse. Could be he is old school and has seen one fail so i t turned him off them all. So far the one I have seems ok.

You should have a fuse between any power source and battery.
 
BOWHOUSE52 said:
Hi not able to afford Lithium not sure if this is the right thread to bring this up but been going though a similar dilemma so looking at AGM or Gell any comments please would be greatly received thanks
Click to expand...

Probably best to start your own topic, but have a look at:

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Thnx for input wtf but as I was about to reply to you you say to bowhouse about Leoch AGM's
Funnily enough I having to replace batteries after 2 years.......guess what I had to replace yes 2 100ah Leoch AGM's

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In particular those lead carbon ones, which would seem to deal with the disadvantages of AGM (particularly tolerance of high temperature). Just as long as you have an AGM setting on any charging equipment.
 
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Minxy Girl said:
On previous campers I just put a fuse holder in the positive wire for each of my solar panels between the panel and the solar regulator, that way I could just pull the fuse when I wanted to isolate them from the system. Do NOT put one between the solar regulator and the vehicle's battery or electroblock (or equivalent) as it could cause serious damage to the solar regulator if there is nowhere for the 'input' power to go to.
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Minxy Girl said:
On previous campers I just put a fuse holder in the positive wire for each of my solar panels between the panel and the solar regulator, that way I could just pull the fuse when I wanted to isolate them from the system. Do NOT put one between the solar regulator and the vehicle's battery or electroblock (or equivalent) as it could cause serious damage to the solar regulator if there is nowhere for the 'input' power to go to.
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Oops. I have switches between mine and the batteries so I can isolate them to prevent them from draining the battery when not in sunlight or if I’m disconnecting the batteries etc. Not that I ever really turn them off but thought when fitting it may be useful. Never thought about what would happen if the input power had no where to go. Best make sure I leave either the cab or the habitation switched on just in case. I also have fuses on the panel wiring I could pull as well if needed. Might be safer. Lol
 
There is no input power to go anywhere if a panel is open circuit!

Still!
 
On the front face of the Votronic duo solar regulator there is a fuse.

I was wondering.......if you pull out the fuse, does this isolate the panel from the regulator ???

PS. Just curious, as I'm thinking of purchasing this product.
 
Wagoneer said:
On the front face of the Votronic duo solar regulator there is a fuse.

I was wondering.......if you pull out the fuse, does this isolate the panel from the regulator ???

PS. Just curious, as I'm thinking of purchasing this product.
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No, it's in the battery circuit.

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Hi Richard I was thinking this too Nightmare wish I had not thought of upgrading my solar system :mad::mad:
 
andy63 said:
You lost me there Mel.. That's exactly where you do put a fuse on the solar system and the ones ive done the instructions tell you to fuse the output side of the controller..
The input or panel side is protected anyway and instructions don't generally ask for a fuse there... But as you have said it can be a handy way of isolating the panels?
Andy
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I believe in putting a fuse inline on the + output from a solar panel as there supposedly have been fires caused by runaway panels and the regulator has not tripped them out. So an extra fuse is a good idea, as is treating a solar panel like a live battery, so in my book it requires a fuse before going into anything else.
 
MR. FUSION said:
I believe in putting a fuse inline on the + output from a solar panel as there supposedly have been fires caused by runaway panels and the regulator has not tripped them out. So an extra fuse is a good idea, as is treating a solar panel like a live battery, so in my book it requires a fuse before going into anything else.
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In my book, the more the merrier (amps). Perhaps these runaway panels are better than normal panels, and could attract a premium? ? ?
 
MR. FUSION said:
I believe in putting a fuse inline on the + output from a solar panel as there supposedly have been fires caused by runaway panels and the regulator has not tripped them out. So an extra fuse is a good idea, as is treating a solar panel like a live battery, so in my book it requires a fuse before going into anything else.
Click to expand...
hmm thats a new one on me.. runaway panels..:unsure:
as I said i dont see any real advantage in fusing the panel side other than a convenient way of isolation..
the controller has adequate protection built in... yes a fuse is an additional level but to be useful would need to be a small one as all it would be protecting is the controller..
but using that as an example how many fuses or levels of protection do you need in case one doesn't work.. we are talking about a solar installation here...
the short circuit current of most panels and installations could be more than coped with by the wirings used without any danger to the wiring... not like the average leisure battery where the short circuit current would be a danger..
my view.. we may have to agree to differ (y)
Andy
 
poppycamper said:
And i saw those graphs in the instruction booklet. Give me an engine.. fuel injector.. carberator or anything mechanical then I your man. BUT they really don't mean a thing to me.. I have tried to make sense of them but couldn't so that is why I asked on here.
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These graphs are not in fact the charging profile graphs. They are graphs of the how the absorption voltage (U1) and float voltage (U2) vary with temperature. For LiFePO4, they don't vary at all - they cut off when the temperature gets too high or too low, but otherwise they are constant.

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