Nowty Towers DIY Battery Project

[Joeboy]

..................That is a sleek looking job Nowty. How many days can you now run OG in Winter? (Nov to Feb).

Well that is one of the reasons for the capacity increase, if I am to ditch the gas boiler I want to be confident that I can run the heatpumps for heating in the worst time of the year for 1.5 or 2 days. I have not run the gas boiler in anger for around 2 years now but I want to be confident of being OK even if we have a 24hr leccy power cut. The longest we have been without power in the past decade is about 12 hours, we have had a couple of 6 hour outages as well.

The extra capacity increase will also allow significantly more paid export and give me the advantage of running in the summer at say 50% SOC and facilitate loads of charging headroom to reduce the amount of curtailment if we are on holiday. The latest increase in capacity has been cost neutral in that the sale of my 23kWh 7.5 year old Pylontechs have paid for 32kWh of brand new capacity.

Of course I have extra ancillary costs and the pylontechs are possibly the most robust stand alone batteries you can buy.

That's great, you've got your remote control of export/import. The home will pay towards the holiday in your absence. We go next week, interested to see what it will produce. Somewhere around £60 I with no grid draw. All the best with the tests!

[nowty]

Battery bank 4 is now in service undergoing operational trials.

I decided not to bother with the fused links on the balancer this time but I've made a tidier job of them tying them back up to the upper bar.

[MikeNovack]

I want to be confident of being OK even if we have a 24hr leccy power cut. The longest we have been without power in the past decade is about 12 hours, we have had a couple of 6 hour outages as well.

Which is why different for me. But first I will point out that if you had 24 hour NORMAL consumption you'd have more emergency time. If you knew you were in an extended power outage could allow the house temp to drop some, restrict use of hot water, etc.

HERE (NOT in a city) could expect one as long as 12 hours annually, in a decade one of 1-2 days, and in the 40 years we have been here two 3-5 day events. FIRST they have to clear/reconstruct roads enough for emergencies and only then can the utility repair trucks get in. Just two miles farther up our road they experienced those events as 1-2 WEEKS. The reason why our stretch of the road can be gotten to quicker is there is a terrible unpaved shortcut up over the hill so not subject to total destruction from floods to our part of the valley even if our road/bridges gone upstream and downstream.

[nowty]

I want to be confident of being OK even if we have a 24hr leccy power cut. The longest we have been without power in the past decade is about 12 hours, we have had a couple of 6 hour outages as well.

Which is why different for me. But first I will point out that if you had 24 hour NORMAL consumption you'd have more emergency time. If you knew you were in an extended power outage could allow the house temp to drop some, restrict use of hot water, etc.

HERE (NOT in a city) could expect one as long as 12 hours annually, in a decade one of 1-2 days, and in the 40 years we have been here two 3-5 day events. FIRST they have to clear/reconstruct roads enough for emergencies and only then can the utility repair trucks get in. Just two miles farther up our road they experienced those events as 1-2 WEEKS. The reason why our stretch of the road can be gotten to quicker is there is a terrible unpaved shortcut up over the hill so not subject to total destruction from floods to our part of the valley even if our road/bridges gone upstream and downstream.

In a power cut at Nowty Towers we open the curtains and turn all the lights on to wind up the non battery folk, which is basically everyone in the street.

[resybaby]

The UK's answer to Warlock in the Die Hard film there Nowty

[Moxi]

I want to be confident of being OK even if we have a 24hr leccy power cut. The longest we have been without power in the past decade is about 12 hours, we have had a couple of 6 hour outages as well.

Which is why different for me. But first I will point out that if you had 24 hour NORMAL consumption you'd have more emergency time. If you knew you were in an extended power outage could allow the house temp to drop some, restrict use of hot water, etc.

HERE (NOT in a city) could expect one as long as 12 hours annually, in a decade one of 1-2 days, and in the 40 years we have been here two 3-5 day events. FIRST they have to clear/reconstruct roads enough for emergencies and only then can the utility repair trucks get in. Just two miles farther up our road they experienced those events as 1-2 WEEKS. The reason why our stretch of the road can be gotten to quicker is there is a terrible unpaved shortcut up over the hill so not subject to total destruction from floods to our part of the valley even if our road/bridges gone upstream and downstream.

In a power cut at Nowty Towers we open the curtains and turn all the lights on to wind up the non battery folk, which is basically everyone in the street.

Nowty,

You should have a chat with your neighbours and rent their roofs for more solar panels just putting the idea out there

Moxi

[Stinsy]

Which is why different for me. But first I will point out that if you had 24 hour NORMAL consumption you'd have more emergency time. If you knew you were in an extended power outage could allow the house temp to drop some, restrict use of hot water, etc.

HERE (NOT in a city) could expect one as long as 12 hours annually, in a decade one of 1-2 days, and in the 40 years we have been here two 3-5 day events. FIRST they have to clear/reconstruct roads enough for emergencies and only then can the utility repair trucks get in. Just two miles farther up our road they experienced those events as 1-2 WEEKS. The reason why our stretch of the road can be gotten to quicker is there is a terrible unpaved shortcut up over the hill so not subject to total destruction from floods to our part of the valley even if our road/bridges gone upstream and downstream.

In a power cut at Nowty Towers we open the curtains and turn all the lights on to wind up the non battery folk, which is basically everyone in the street.

Nowty,

You should have a chat with your neighbours and rent their roofs for more solar panels just putting the idea out there

Moxi

My roof is horrible for solar panels. All in all they're split between 4x arrays.

My next door neighbour has a perfect 8m x 5m rectangular roof that could easily for 7kWp on the south side and another 7kWp on the North side!

[nowty]

To recap, I have 4 battery Banks
Battery Bank 1 is 24.37 kWh of LMC but is a decade old.
Battery Bank 2 is 24.37 kWh of LMC but is a decade old.
Battery Bank 3 is 28.67 kWh of LFP and is only a month old.
Battery Bank 4 is 32.26 kWh of LFP and is only a couple of days old.
-----------------------------------------
Total Gross Capacity 109.67 kWh

All 4 battery banks are at around 55.7V after a very long charge up so battery banks 1 and 2 (14 cell LMC) will be at around 93% SOC and battery banks 3 and 4 will be around 99% SOC. The new bank 4 seems to have a slightly less flat charge/discharge profile when compared with bank 3. My cell balancer on the new bank is working well, all cells are typically within around 50mV when arriving at the top end.

I'm going to discharge for maybe 24hrs to see how many Ah's the whole system has as counted by my Victron SmartShunt. My voltage cuttoff will be 47V, at which point banks 1 and 2 will be around 20% SOC and banks 3 and 4 (16 cell LFP) will be around 5% SOC. The batteries may start to charge a little in the middle of the day but the SmartShunt takes that into account and adds the Ah's back.

The discharge has started at midnight, I have set the battery size at 1953Ah which is an arbitrary 100kWh at a cell voltage of 3.2V. Probably too optimistic but it will get my SOC graph in the ball park and the time to go estimate reasonably meaningful.

[Stinsy]

At what point will you scrap the old batteries? I guess they have a very high lithium content. Do they have scarp value or are they in the pay someone to take them away territory?

[nowty]

At what point will you scrap the old batteries? I guess they have a very high lithium content. Do they have scarp value or are they in the pay someone to take them away territory?

They will be here for another decade or longer, or if they finally degrade too much, I will be doing a capacity test on them soon to find out their SOH.