New Electrical System (Solar, DIY Winston LiFePo4, BMS, Victron)

[rolandsaven]

I’m designing a new electrical system, however, I’m pretty new to this and would like to ask some of the experts here. I started out this to be a really simple design and now it’s getting way more complicated.

I’ve chosen the DIY lithium battery route instead of pre-made batteries due to cost. There are not so much information out there (in English) for DIY lithium batteries so you guys might have some experience in this.

Anyway, you can see the wiring diagram attached and I’ll just put the list of the main components.

• Victron MultiPlus 12/3000/120 16A
• Victron SmartSolar MPPT 100/50
• 4 x 100W 24V Mono Solar Panel
• Victron BatteryProtect BP-65
• Victron BatteryProtect BP-100
• Victron Lynx Distributor
• Victron BMV-712
• Victron Venus-GX
• 4 x Winston 3.2V 260Ah Cell
• 123Smart BMS or (REC Active BMS)

My questions:

1. Is there any advantage using Victron’s BatteryProtect product over a simple latching relay? This is for the BMS123 Smart to switch off the load and/or the charge bus/devices?
2. MPPT’s max charge current is 50Ah. Is the BP-65 a good choice?
3. Do I need to use a fuse or a circuit breaker between the PV array (solar panels) and the MPPT charger?
4. The cables measured one way. Are the cable grades correct?
5. Can I connect a switch to the remote port of the BatteryProtect while it is connected to the BMS? This is to be able to manually switch on/off the BatteryProtect. (so it would act as a switch when servicing)
6. 123Smart BMS is used in the schematic but I'm considering the use of REC Active BMS. The main reason is that it has a CANbus port to communicate with Victron devices. In the other hand, there is an Extended module for 123Smart BMS which has a CANbus port too. Now the problem is that it does not support Victron products by default according to the manufacturer but I should be able to make it work as the pin layout is in the manual for making custom connections. Anyone did such thing before?

Any help appreciated....

Thanks guys

 

[hilldweller]

Any help appreciated....
Thanks guys

Yes.

KISS

Yes, all singing all dancing with CANBUS clever is brilliant, as long as it's working, but in a field in a snow storm a relay wins every time if it goes wrong.

Recently, some poor soul on here had to go to the manufacturer's factory in Germany because the software in his mega complex electric system got a glitch and shut his power down trapping him in the vehicle.

Think about it, all you are doing is charging a battery and using it to power your gadgets. Even a relay is overkill.

 

[Gromett]

@Wissel is in the process of a very similar project.

 

[Gromett]

Yes, all singing all dancing with CANBUS clever is brilliant, as long as it's working, but in a field in a snow storm a relay wins every time if it goes wrong.

I think the OP might be a little confused. The Victron products use what they call ve.Bus. This is not CANBUS. Although Victron do supply a ve.Bus to CANBUS adapter. You don't need this to get the most out of the system as the ve.Bus is pretty good.

 

[rolandsaven]

@Wissel is in the process of a very similar project.

I've spoken to him on another forum, I like the system he designed. Similar features with less complication and weight.

^{_{Subscribers  do not see these advertisements}}

 

[rolandsaven]

I think the OP might be a little confused. The Victron products use what they call ve.Bus. This is not CANBUS. Although Victron do supply a ve.Bus to CANBUS adapter. You don't need this to get the most out of the system as the ve.Bus is pretty good.

Yeah, it is indeed confusing. The connection between REC Active BMS and Victron is explained here. It seems like there are multiple options/ways to connect. There is also a VE.BUS to CANBUS adapter you're right but I'm not very familiar with any of the mentioned bus standards and the possibilities.

I have a Venus GX which has all the ports plus there is a CAN-bus port that is accessible via the GND, CAN-H and CAN-L terminals on the left of the product. (picture) There is also a discussion on enabling it via terminal. I do feel like it's an overkill though, but if I have the time I might be able to get it working with the extended module of 123Smart BMS. Though I'm not sure if it is possible at all...

 

[rolandsaven]

Yes.
Think about it, all you are doing is charging a battery and using it to power your gadgets. Even a relay is overkill.

I agree on that.