System change

solarflux
solarflux Registered Users Posts: 2

Hi we live offgid since 2002 and our present system is 24v with 1kw PV and a 3 meter diameter Hugh Piggott wind turbine.

Our batteries are 12 year old 2V OPzS 600s 900AH at C100.

Our power needs have changed as we have got a PHEV and it would make sense to charge it from our system so I have arriving shortly 30 4 year old Kyocera 54 cell modules that I got on a special deal.

Nominal capacity: 208.4 Wp

MPP current: 7.84 A

MPP voltage: 26.6 V

Short circuit current: 8.5 A

Open circuit voltage: 33.2 V

And into the mix just to make things more fun I was given a 8 year old electric car with one or two bad cells.

It has 84 100AH CALB cells. It was a so called professional build but the company have now disowned the cars so I'm scrapping that.

I have two old 2007 outback mx60s and it looks like I could use them with the Kyoceras 15 panels on each to charge a 48v bank made up from the lithium cells and buy a nice big 48v victron multiplus inverter/charger and still keep our 24v system going as it is.

Now the question how best to manage the lithium cells what bms to get or just sell the cells and buy some more old tech batteries and upgrade our whole system.

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭

    This would be an opportunity to to build a new LFP system while still using the LA system. The BMS question depends on how much current, charg/discharge, is required, in my case I supplied the information to a BMS manufacturer who recommended a model based on requirements. Currently I still have a LA system which I use during certain hours using an inverter block and an auto transfer switch, mainly to optimize both systems. As long as there is no problem keeping the LFP batteries above freezing then it would be a positive move, in my opinion, as the performance is on another level compared to the old tech battery option.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • solarflux
    solarflux Registered Users Posts: 2

    Thanks @mcgivor could you recommend a BMS manufacturer.

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭

    The manufacturer I used is http://lws-pcm.com/en/index.html# depending on needs, display, WiFi connectivity, adjustability and so forth there are many choices. The one I have has none of the aforementioned features, but I do have a second BMS for monitoring purposes only, it's a little complicated, so I'm reluctant to recommend anything, other than to say I'm happy with my choice. The reasons are because it is tailored to my system requirements as specified to the manufacturer, It is also different to some others in that it has dual ports, one for charging, another for dischargeing. At this point I'm only 8 months into the LFP venture, but very happy I made the switch from LA, in some way I'm anxious about the failure of the LA bank, so that I can finally rid myself of that technology and it's shortcomings.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.