diy solar

diy solar

Need help understanding my solar set up !

Ebay and Amazon could be a source. These are standard automotive fuses so should be available from an auto electrical specialist. I suggest buying from a company in Europe rather than aliexpress ( assuming you are based in France)

Yes, the fuse distribution holder effectively combines the buss bar and fuse holders, the style in the picture having one mega fuse position and 4 midi fuse.

This is the 'master' fuse fitted as close as practical to the battery positive post.
Any cable regardless of length should be fused to protect the cable from currents higher than the rated maximum.
The absolute maximum allowed currents are, 10mm2, 70A, 16mm2 110A, 25mm2 170A.

The battery you are using is a lithium battery, should there be a fault somewhere in the circuit, ( a accidental connection between the positive and negative) and the BMS were to fail to protect, (open the output path) then the battery will deliver a very high current ( 1000s of amps) , this will melt cable insulation and cause a fire.

The automotive mega fuse is only rated for interrupting 2000 amps

in order of current interrupt performance using quality branded fuses with a 12v battery,
mega fuse, 2000 amps
ANL fuse , 6000 amps
MRBF fuse, 10,000 amps
Class T fuse, 20,000 amps

The Blue sea MRBF fuse and fuse holder, whilst not offering the highest protection of the Class T fuse, is acceptable in my view.

Component part and diagram changes make it difficult to offer advice. The Aili may give passable performance but does not have the programmable relay that the BMV series have.

Because you do not have the inverters connected to the Victron battery protect, any low voltage protection will have to be carried out by the battery BMS or the low voltage shutdown in the inverters.
This should be enough to protect the battery from low voltage.

If you need additional protection against low voltage for the fridge inverter, then the relay contacts in the Victron Battery Protect, could be added in series with the enable control to the inverter.

What BMS are you using? Is It user programmable?
Can the inverter low voltage shutdown levels be user programmed. if not what are they set at?

It would seem you have enough solar and battery capacity to power the fridge for long periods and its unlikely, since you have battery monitoring with the AiLi and perhaps a smart BMS, you will not allow the battery volts to fall too low.
In the unlikely event the battery becomes too discharged, the BMS will shutdown.


Fitting a switch between the panels and controller rated for the input DC current and voltage would disconnect the panels.
To completely isolate the system from the battery you could add a battery isolation switch between the 'master fuse' at the battery and the rest of the circuit.


Mike
I don’t mean to jump in your thread , however I am looking for a good fused / breaker disconnect to isolate and protect my all in one lv24/24 unit . Link was to French site . Just started in forum not sure if this was rude
 
Hi all,

I am currently modifying my solar set up following Mike's recommandations.

I bought two battery switches and I thought I would add one of them between my solar panels and my MPPT however I think it's way too big ! ... The nuts are M8 and my solar cable is 6mm2 ...

What other switch can be used in this case ?
 
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Hi Mike,

Thank you ! I just ordered some of these.

I also bought the CBE CSB2 (battery master) and I had some questions about the way to connect it.
I was going to use 2,5 mm2 wires with this kind of fuse (10 A) for the car battery. Is that okay?
1636300319875.png
1636300492802.png
Can I connect my cable directly on the car battery terminal ?
1636300883523.png

I was going to connect earth right here (my earth is not connected to the chassis, is that correct ?) and the service battery directly on the fuse box. Should I add a wire from the fuse box to the service battery terminal ? I guess it's already wired but I am a bit confused.
1636300730752.png

Finally, I'd like to add a switch. Would this kind be okay ?
1636301077028.png

Thank you so much,
Marine
 
To be more clear, here is the wiring I'd like to do for the "battery master". Does it seem right ?

1636476028969.png
 
Hi,

I found out that CBE made a new product, the CSB2-LT for lithium batteries only.

Here is what they say in the user's manual :

"When the leisure battery voltage is lower than 12.5V or in the absence of a “230V network signal” and “solar signal”, the car battery recharging system is deactivated".

Does it mean that at night, the CSB2 is disactivated for example ?
Is it really worth it to choose the lithium version as it is twice the price ? I was worried to fully discharged my leisure battery if I don't pay attention.

Here is how to connect it. I don't know exactly how I can connect it to the "input solar signal" and "input 230 V". Should I add a second cable in the PV and IP22 charger positive terminal ?

1637249514863.png
 
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