Jimbo_100
New member
Hi Jimbo,
Welcome aboard.
It sounds like your proposed system is a copy of mine that Ive just done (switched on 24th December).
Why 2 x Mason Cases? The 280 case can take the full 16 battery count. I very nearly used the Mason case myself but built a small shed instead to house the inverter too.
If you bought your batteries from Fogstar and/or they come with small bits of threaded ron and nuts with built in locking, I threw them away, I couldnt get good tension with the torque specified. I replaced them with nuts, spring and plain washers (M6 from B&Q bulk section, £5 for whatever you can fit in a bag)
The Multiplus II is a great inverter, you should opt for the GX version if you can, that gives you all of the comms built in too so you dont need to buy a CERBO GX in addition.
Hi John,Choose the DC switch and fuse wisely DC supplied by batteries can be brutal.
I purchased 35mm2 cable from ebay for the wire up.
Good luck, keep us posted, start a build thread.
Cheers for the welcome, I look forward to learning and contributing if I can, I'll start a build thread once back onshore to hopefully help others navigate their journey.
It was your very thread I stumbled on earlier this month that led me here, I've enjoyed reading your journey and in many ways it has reassured me I was pointing in the right direction with the array of options available out there.
Back in November I took the plunge and purchased 32 x LF280K Batteries (not 16 as i mentioned in the intro) and 2 x JK-B2A20S20P BMS's with BT on Alibaba. They arrived the morning I was due to fly out to the Rig on 20-Jan-23 (Delivery lad was a star and helped me move them inside). Back when I ordered them I had planned to build a double rack assembly and mount in the garage under the workbench in a thermostatically controlled encloser.
I'd been watching Andy @ the offgrid garage on Youtube in Oz and felt comfortable with building a rack system in my garage to do my DIY Powerwall. Later I decided to invest in the Seplos Mason DIY x 2 as it looked a more eloquent solution and the BMS has support for the Victron gear on its forums. I wanted to use the Victron gear straight from the outset as I had experience in setting up offgrid camping and solar setups in caravans when we lived in Oz, the gear is expensive but 1st class in build quality & support and recognised the world over for operating in tough conditions flawlessly.
There will be bus bars and M6 rod in the boxes with the batteries and also provided with the Seplos DIY kit. I'm a wee bit nervous I strip the top connectors on the Batteries and was considering investing in a suitable torque wrench. I prefer your suggestion of plain and spring washers to ensure a good contact. Also i suspect the batteries I've purchased have a single M6 threaded connector on the top of the battery from the spec sheet they sent through.
The Multiplus II is a great inverter, you should opt for the GX version if you can
I've taken your advise and sourced one on Amazon for £2000 at Batterie Megastore saving around £300 from the other UK supplier I had initially considered, good call m8.
Dont buy the official Victron CT, buy a generic one and save £100.
As I'm planning on storing the system in the garage is there any issue regarding a minimum distance between the meter box where the distribution board (I'm assuming the CT clamp is installed near the distribution panel where power comes into the house so as to sense potential import / export) I recon there will be approximately 15m cable routing. Note the garage is seperate from the main property by 1.5m with service conduit up thru the floor feeding power and water etc.
This leads me onto another question as the AC feed into the garage has a small distribution panel with a breakers / RCD running 2 x 13 amp double wall sockets and the lights. I've not physically verified the cable specs running to garage only the main breaker size 30A in the House consumer unit.
I do not feel the present wiring configuration is suitable to connect the Victron inverter to the consumer unit and will require cable sizing verification / upgrading and increased breaker sizing in the consumer unit (potentially a new consumer unit in the house as all breaker spaces are occupied). Now whilst I'm candidly discussing such matters be reassured this is not my area of expertise nor will I be undertaking the connection or disconnection of such devises. Whilst I'm happy to run cables to both ends under the floor space and drill holes and mount boxes etc the termination in and out will fall to a certified Electrician not me! However, I do wish to understand the sizing & termination process so i can better plan / source the right peeps to come do the work.
I purchased 35mm2 cable from ebay for the wire up.
I have read on a few forums to be very careful regarding sourcing the cabling (from china mainly) used to connect DC cables due to inferior material being used in construction (copper coated aluminium etc) who did you use on E-bay?
Choose the DC switch and fuse wisely DC supplied by batteries can be brutal.
An oversight on the Seplos Mason IMO is the lack of a DC breaker switch within the unit front panel to allow complete isolation from the DC bus / invertor TBH. Since i'm using 2 x Seplos Mason units I was considering joining them via a dedicated Victron Bus bar / shunt with 150 amp fuses on + & - and connect each battery with a dedicated isolation switch. Thereafter, from the DC switch each battery is connected with equal lengths of 35mm2 cable to the front of the unit via their proprietary connectors (note both batteries to have the same minimum length 35mm2 cables). My thinking is that the bus bar will also be my means of DC connecting the (future solar panels) via dedicated Victron Solar controller all chatting / monitored on the VE bus and Victron VRM. I'm still toying with the array sizing and E / S / W configuration all of which are available to me. As so often is the case in life we look for reassurance to ensure were not gonna make an expensive mistake or simply missed the obvious due to some rule / regulation were not familiar with.
Best Regards Jimbo
Split from introduce yourself
Last edited by a moderator: