Solar panel, 12v battery charging problem

[Ableur]

Hello everyone,

I stuck on a (stupid) battery charging problem with my solar panel. Indeed, even in direct sunlight, the battery does not recharge. When I connect the mains charger (15a), it works on the other hand, it charges correctly and I see it via the battery application (bms).

Here are the components that make up my setup:

Solar kit: EM MPPT 55/20-BT Solar Regulator / 280W black solar panel with By-pass diode junction box and 1.5 m cable with MC4 termination

Link: https://www.h2r-equipements.com/kit...neau-solaire-souple-perc-flex-280-w-noir.html

4s 12v 150ah battery with home assembly.
Link: https://fr.aliexpress.com/item/1005...t_main.10.2a495e5batQTDq&gatewayAdapt=glo2eng
BMS 60A, LiFePo4 4S 12V BT: https://fr.aliexpress.com/item/1005...st_main.5.2a495e5batQTDq&gatewayAdapt=glo2eng

=> The assembly was done with an electrician. We are missing a fuse dedicated to the solar panel (which we will put soon).
Here is a photo of the assembly:



My observations:
- According to the application of the MPPT, I see many Watts which are generated by the solar panel, I have a quite correct voltage/amperage but nevertheless, I do not see anything passed at the level of the battery (I should see ampere "courant", but it remains at 0. When I recharge via the 15A mains charger, I see 15.2A and I note that the percentage of the battery increases).
We tested the voltages with a voltmeter, they match to what we can see on the MPPT application.
I'm stuck and I need a hand. We thought there was a problem with the + block, but we rechecked the (+) and RAS on it, connection was OK.

- I downloaded the manual to understand the meaning of the LEDs on the MPPT, and it seems correct to me: SOC3: "battery between 50-90%"; quick flash "MPPT Charge"; Blue LED: "Battery is normal"
I have one last thing to do, unplug everything to leave only the battery + bms + solar panel ... I'll test it tomorrow afternoon.






If you have an idea...I'm in !, thank you

 

[Zapper77]

Are you bypassing the BMS for dis/charging? Looks like you are in the 1st photo.



Is that rated for 100 amps?


Where does the inverter get DC from?

 

[mikefitz]

The screen shots for the solar controller clearly show current is being sent to the battery, 14.2 amps, battery 13.5 v, and 1.3 amps 13.2 v.

This is not being recorded by the BMS since the wiring of the BMS is incorrect, all loads and chargers negatives should be connected to the BMS black cable, P-.



Your electrical specialist needs educating .
Whilst a fuse for the single panel is not needed, an isolation switch is useful for system maintenence.
A main fuse near the battery positive terminal post is needed, this may be in position, but not shown in the picture.

Not shown are over current protection, ( fuses or breakers) for each of the feed cables to, inverter, mains charger, solar controller, and distribution to other parts of the electrical system.

The solar cables entering the vehicle via the door seal is hopefully a tempory measure.

The blue and brown cables shown look like house wiring cables , not the multi strand automotive grade cable needed for mobile applications.


It's concerning but not surprising that this install was carried out by a 'professional electrician'.

Mike

 

[Ableur]

Hello guys,
Thank you very much for your answer and taking some time, it's helping me a lot.
I will fix the wire issue and come back to you.
Yes, it's rated for 150 amps.
Yes, the solar panel was installed few days ago. We need to make things "proper and cleaner" regarding the wire from the solar panel to the vehicle.

 

[Ableur]

To summarize :
- The only thing that must plug on the (-) of the battery is the (B-) of the BMS (which is not the case on my setup here) ;
- The (+) of the battery should be wire with the charger (Victron of MPPT) ;
- The (-) of the the charger (Victron or MPPT) should be plug with the (P-) of the BMS.

With that, it should rock !
Keep you update.

 

[Ableur]

Thanks to you Zapper77 / mikefitz it's working now ! I don't know what the fuck we did, the first try of the battery in the winter was correct and the final builtin sucks (memory...), we did not follow properly the schema/diagram...don't ask me why.

I'd like to take your "best practice" to have the "best" meaning safe solution for my van.
To summarize :
- I need a main fuse after the battery (on the picture, you can't see it, but we have one) ;
- Fuse for a single panel is not mandatory but I need to consider to install an isolation switch for maintenance (the switch that I got is not enough ? I guess the purpose is not the same ?)
- The "only" protection that I got, is the switch button (you can see it) and the fuse that you cannot see on the picture. You do recommand to use a fuse for each component (MPPT / 12v => 230v (Victron) and charger (Victron) right ?
- Cable are coming from the industry, it's flexible cable. Probably not made for automobile but as long as it is flexible with the right ², it should be OK no ?
- For the wire from solar panel to the car, we need to think and make something correct...still thinking about the best way to do it without exceed 2meters.

Thanks again guys