@makia2023 I hooked up the cell monitoring lines before connecting the B+ cable (circled red) from the pack to the BMS. After about 2 mins I noticed the telltale smell of hot conformal coating coming from the area around the balance resistors (circled green).
Seplos V3 has the shunts in the -ve bus, unlike V2 which had a separate shunt onboard in the +ve bus, hence the need for a bat+ sense wire.
The BMS powers up fine but it reads 0mV for all the cell voltages. It reads the pack voltage correctly however.
I think I'll order a replacement from fogstar, I could swap my batrium over from my 9.6kWh pack, but it's very much not reliable, and it would be some work to make it all fit.
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
@hughf - balance resistors ... in an active balancer model?
What are they doing there?
Save energy... recycle electrons!
@transparent The seplos v3 is the standard passive balancing BMS, their 'active balancer' is a separate unit that connects via an additional harness, directly to the cells. It is non-programmable, and works at any cell voltage >3V, when there is a 50mV delta.
It's generally considered to be 'a bit junk', as it's not programmable and can't be enabled only at >3.45V/cell.
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
@Transparent - as it will be set low AND should be fed using the electricity from the battery, then i thought it was a reasonable option, especially if i insulated the heating pad and rear of the Seplos with a couple of inches of celotex or similar.
@Makia2023 - i did consider something similar but decided against it as i wanted to stop the battery from dropping below charging levels, as opposed to heating the immediate are its in.
New bms delivered today from fogstar, all installed and up and running 👍
Now to find that 3kW charger I’ve got somewhere….
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
Expand that comment please @makia2023
The full SunSynk diagram of all possible configurations has three CTs on it. 🙄
I'm going to assume that you're referring to the one which connects to positions 5 & 6 on the Inverter, and has the clamp/transformer around the live feed wire between the inverter and its mcb-trip in your consumer unit.
In the manual, you probably have this diagram, and will have read the comments below and to the right:
See also the table at the bottom of the following page.
Although it's beneath the diagram which covers installation in the USA, it's still relevant.
What reading do you get if you disconnect the CT-clamp wires from the inverter, and use a multimeter set to ohms?
Save energy... recycle electrons!
Having more than one multimeter would seem a prudent investment for someone who's just imported 64 lithium cells from China!
I have three multimeters, one 'mains tester' box and an assortment of dedicated current/voltage meters.
And yes, I have needed to use all of them simultaneously on one occasion!
I've just checked online, and Amazon have at least 50 multimeter models, auto-ranging, at less than £30 and available for delivery on Saturday!
Give yourself an 'essential' Christmas present.
Save energy... recycle electrons!
I have a spare. I'm getting no reading from either my old or new ct clamp with it. Any thoughts?
I'm tempted to run another cat 6 cable separately and see if that works. But will be a tomorrow thing. I'm stumped.
It should definitely see the grid load regardless of battery system/solar right?
- 26 Forums
- 2,129 Topics
- 46.8 K Posts
- 16 Online
- 5,654 Members
Join Us!
Podcast Picks
Latest Posts
-
RE: Mitsu Wireless Controller and MelCloud
@morgan Yes, "Prohibit" was the word for when switched...
By DavidAlgarve , 3 hours ago
-
RE: Heat Pump Servicing & Maintenance – Good Value or Rip-Off?
For reference, our installer has just contacted us afte...
By Old_Scientist , 7 hours ago
-
@toodles Of course. I've also used Tim and Kat's Gree...
By Old_Scientist , 7 hours ago
-
RE: Who's your electricity provider and what's your tariff?
Yes, I noticed that change too. The software really doe...
By Old_Scientist , 7 hours ago
-
RE: Octopus Cosy & Octopus EV + bidirectional smart tariff, together. What, eh?
@old_scientist me too. Just installed my new heat pump ...
By Eliuccio , 1 day ago
-
RE: Is your heat pump insured?
Yup just spoke to Privilege to inform them of my impend...
By Scalextrix , 1 day ago
-
RE: Forum updates, announcements & issues
Just to keep everyone in the loop, as the site continue...
By Mars , 1 day ago
-
RE: Fast DHW setting on Midea (Clivet) heat pump
@simon-w, is this something you could potentially assis...
By Mars , 2 days ago
-
RE: Share Your Experiences with Heat Pump Manufacturer Support
Fwiw I called my installer out for the first time a few...
By JamesPa , 2 days ago
-
RE: New Vaillant aroTherm Plus in black - When will it come to the UK?
@sandy, I'll send Vaillant an email tomorrow and see if...
By Mars , 2 days ago
-
RE: Long term efficiency degradation
@jamespa yes as I thought thanks. We have a reaso...
By Scalextrix , 2 days ago
-
RE: Who has a V2G EV installation
I agree, but a word of caution. V2X is also sometimes u...
By Majordennisbloodnok , 3 days ago
-
RE: Sunamp Thermino Heat Battery
@jamespa A few days after the installation had been com...
By Toodles , 3 days ago
-
RE: Planning Permission May 2025
Fair enough. I have read the legislation and MCS020a ...
By JamesPa , 5 days ago
-
RE: How do I choose a single room MVHR to prevent losing heat in my bathroom ?
An update on the Heatsava. It is the most difficult thi...
By heat-pump-newbie , 5 days ago
-
RE: ASHP heat output monitoring
@carlo - not much better, is it. It looks more like a u...
By cathodeRay , 6 days ago
-
RE: Renewables & Heat Pumps in the News
this document extensively describes (in a non-blame, ne...
By Judith , 6 days ago
-
RE: Ecodan - Legionella Operation Time and Target Temperature
Once the white plastic cap is removed, my immersion loo...
By Old_Scientist , 1 week ago
-
RE: Replacing Refrigerant on Mitsubishi Heat Pump
@dgclimatecontrol I don't know, but they were not happy...
By DavidAlgarve , 1 week ago
-
RE: Why do we need pressurised systems?
A good question @toodles. My old open thermal store and...
By AllyFish , 1 week ago