Guru
Joined: 12/08/2011
Location: AustraliaPosts: 357
| Posted: 09:52am 10 May 2026 |
Hi All
Don't know how many on this forum have used Sodium Ion prismatic cells,
but I have just spent a couple of months perfecting it for my use.
Purchased 4 x 230AH cells for $230 delivered to Hervey Bay.
I hope the comments below will help someone else b4 they purchase.
Cells:
Veken 72173207-230AH.
I don't believe they are the latest technology available.
They were meant to be shipped at 3% capacity, but were actually at 30%.
The terminals are female M6 at 125mm Centres, which is an improvement on the stud plates
that break off on the Lithium Cells. I put Brass studs into them and then used
Brass Nuts & Washers to connect bars and Inverter Cables.
The cells are fractionally larger and heavier than Lithium Cells.
207H x 175D x 72W and weighs 5.1kg.
My control Board is mounted directly onto the +/- studs.
It uses only copper bars.
No flying lead cables other than the Solar coming in and Loads out.
Voltages.
The quoted capacity is 230AH, but this is from 1.5V to 3.95V per Cell.
So for a 12V system = 6v to 15.8V.
I am using this in a Camper, so 6V is of no use to me.
Similarly, my Renogy Inverter considers anything over 15.375V an error.
Accordingly in my software I have simply reset 100% to 15.4V and 0% to 11V.
That means I lose any capacity over 15.4V and below 11V.
I can go to the limit of say 15.75 as long as I don't try to use the Inverter.
However, a trial of my 1000W Microwave for 5 min, dropped the battery to 80%,
and I am happy with that.
My Brass Monkey fridge has some settings that can be adjusted, otherwise
the high voltage will be considered a Low 24V and it will shutdown.
Balancing:
Even though the cells measure to spec at 0.1mOhm, when connected to the other cells
they do not settle and balance themselves over a week.
Typically they stay about 40mV out of balance.
I installed a 10A Transformer Active balancer.
Control:
Using 2 x ADS1115 boards that equates to 4 Cell Voltages, 1 Differential Solar V
and 1 differential Current shunt V. I do not measure Cell Temperature.
As my Solar is below 40A, I am using 1 x 60A SSR that is pwm .
The software chases MPPT and controls the charging current.
All of this happen on a Rpi Zero 2W with a 10" lcd.
A cpu cooling fan is relay controlled to switch on above 60 C.
No RTC is fitted. The critical info is transmitted to the Cab via Wifi hotspot
onto my GPS screen.
Planning a Camping trip in the next few weeks, so that will be the final test.
Hope this was informative for the Forum members.
Regards
Regards
Hervey Bay Qld.