Nowty Towers DIY Battery Project

[AE-NMidlands]

the insulation will stop radiant or conducted heat gain from outside (so no Bridge on the River Kwai-type furnace,) in the same way that it will slow down or prevent losses in winter.

What it can't do of course is protect the interior from hot air being drawn in... I suspect there might be an external air temperature when it's best to hunker down, let the interior get as high as is acceptable and only draw in enough outside air to dilute the interior heat!

(If it's 35 in the shade outside then ventilation can only bring the internal temp down towards that...)

[NoraBatty]

the insulation will stop radiant or conducted heat gain from outside (so no Bridge on the River Kwai-type furnace,) in the same way that it will slow down or prevent losses in winter.

What it can't do of course is protect the interior from hot air being drawn in... I suspect there might be an external air temperature when it's best to hunker down, let the interior get as high as is acceptable and only draw in enough outside air to dilute the interior heat!

(If it's 35 in the shade outside then ventilation can only bring the internal temp down towards that...)

Very true, but didnt knighty say they were in the North East?! Has the ambient air temperature in the shade ever gotten to 35C where you live, and been sustained for more than a couple of hours or so?!

Even the hottest day of 2022 when it got very close to to 40C in Portsmouth it was only that high for 3-4 hours, then dropped back down quite quickly, and the days prior and after were nowhere near as hot, nor was the rest of the summer.
A cheap portable aircon unit could be sourced on ebay for under 100 quid for these weather extremes and use the extraction vent to cool the area significantly.

I wait to be corrected on this bit, but If you are charging the batteries during off peak, then the inverter is only going to be working hard and pumping out heat at night when its charging. The rest of the time the heat will be far less, especially during the day when you would be using solar too.
Unless ive got it the wrong way round?
Certainly an inverter when charging batteries makes a ton of sound, and therefore i presume heat, whereas when not charging and jist discharging it is barely making a sound that i can discern. Therefore suggests less heat.
I ceetainly am only seeing shed temps spike at night with charging, not discharging.

[nowty]

I have 115kwh of Nissan leaf cells, but I'm planning to have a lot more that that, I'll end up with high amp loads but still low C rates

mostly worried about overnight temps dipping below zero, or extended times in winter below zero (north east England)

shipping container with an A2A system might be best

if I mount the inverters on the outside of it, it means I can relax about busbars a bit etc. don't need to cover them up as much

Your cells are some sort of LMC battery and don't suffer the same problem in the cold as LFP, from top of my head I'm pretty sure they can charge at sub zero temps, I'll try and look them up later for the typical spec.

I have found info quite inconsistent, but most sources including for your Nissan Cells says no to charging below zero degrees. So its not just LFP that does not like charging in cold temps.

[nowty]

Having tightened the busbars on the new battery bank to 3Nm torque, there is no longer any detectable warmth at 100A charge or discharge. The active cell balancer is doing a good job of keeping the cell voltages practically identical, typically all within 5mV.



I also did a tidy up job of the Victron SmartShunt and removed my low voltage Pylontech disconnect relay which is now redundant.
From this,


To this,




And now the Pylontech's are gone, there is a space to fill in the battery cave.

Now you see them,



Now you don't,



A second battery frame has been constructed and is on standby.