diy solar

diy solar

Just bought 16 Eve LF280K A grade; update on degradation after 15 months

MisterB1959 said:
can you provide some detail re the heating pad please?
Click to expand...
Hi, i bought one of these:

www.ebay.co.uk

Seedling Heating Mat + Thermostat Greenhouse Heat Propagator Plant Seed temp con 705495126609 | eBay

Find many great new & used options and get the best deals for Seedling Heating Mat + Thermostat Greenhouse Heat Propagator Plant Seed temp con at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk

240v 20w heating pad which simply activates using this clever device: ( i have it set to come on if temp drops below 7.5deg and switch off at 10deg.) - needed atm and over the next few weeks as predicting some cold weather!

www.ebay.co.uk

2xThermostat-Plug In Electric Digital Temperature Controller Sensor Socket Timer | eBay

(start temperature > stop temperature, cooling; start temperature < stop temperature, heating). More functions: 1.7m NTC 10K temperature sensor probe. Large LCD display. Reset function. Set range: 0~99 hours 59 minutes.
www.ebay.co.uk
 
Looks like you've left some space around the batteries for some pir insulation too ♨️
 
Personally I'm aiming to keep mine above 15 degrees. As LFPs deliver 20% less energy at 0 than 20 degrees, then (for grid-tied systems) it seems worthwhile using just a few watts of power to keep them nearer to 20 degrees than (say) 5 degrees.
 
Last edited:
SeaGal said:
Personally I'm aiming to keep mine above 15 degrees. As LFPs delivery 20% less energy at 0 than 20 degrees, then (for grid-tied systems) it seems worthwhile using just a few watts of power to keep them nearer to 20 degrees than (say) 5 degrees.
Click to expand...
Yeah, i wasnt sure what temp would be optimal, have to look into all that then and maybe up the temperature like you ?
 
Ucatchmydrift said:
Thanks ??. Got the fuse (355amp class t lawson fuse with a 80,000amp interrupt current! - crazy!) from ebay, new without original packing for £15! - bargain. And a piece of perspex for £3 bent into shape. Bit better than £100+ for fuse and holder as it would normally cost ?.

A more upto date picture: (the box on the end is the control module for a junctek bluetooth 400amp shunt which works well, see aliexpress..)
View attachment 122888
View attachment 122889
To control the heating pad:
View attachment 122890
Not finished yet, but not far off.
Click to expand...
Yep, some serious bargains to be had on fuses… with a bit of perseverance. Hopefully it’ll never be needed to quench 80,000 amps!! ⚡️⚡️⚡️

Nice work :)
 
I just received my ZKetech EBC-A40L and started testing one of the cells, following Andy's video here

EC602BF6-9BFE-44B1-A77F-6F94E375461E.jpeg

1671004953946.png


EDIT: After 30 minutes the voltage seems to have dropped while still charging, is this normal?
1671006520176.png
 
Last edited:
Ucatchmydrift said:
Hi, i bought one of these:

www.ebay.co.uk

Seedling Heating Mat + Thermostat Greenhouse Heat Propagator Plant Seed temp con 705495126609 | eBay

Find many great new & used options and get the best deals for Seedling Heating Mat + Thermostat Greenhouse Heat Propagator Plant Seed temp con at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk

240v 20w heating pad which simply activates using this clever device: ( i have it set to come on if temp drops below 7.5deg and switch off at 10deg.) - needed atm and over the next few weeks as predicting some cold weather!

www.ebay.co.uk

2xThermostat-Plug In Electric Digital Temperature Controller Sensor Socket Timer | eBay

(start temperature > stop temperature, cooling; start temperature < stop temperature, heating). More functions: 1.7m NTC 10K temperature sensor probe. Large LCD display. Reset function. Set range: 0~99 hours 59 minutes.
www.ebay.co.uk
Click to expand...
have you installed the pads with the cells on top of them?
 
MisterB1959 said:
have you installed the pads with the cells on top of them?
Click to expand...
Not laying on them no, so as not to damage the heating mat, see here:

20221126_153237.jpg

20221126_153431.jpg


Its a 20w heating mat, and its JUST managing to keep the temp at about 14 degrees. Now have it set to come on at 12 degrees and go off at 15. Its been 0 degrees here in the day now for a couple of weeks, and - 5 at night. In a metal shed outside that has no insulation, and is damn cold in there, but the mat is doing a good job so far. Gunna get another incase it stops working. ?
 
SeaGal said:
Crocodile clips = ?‍♀️

Use proper cables and ring connectors as detailed in this guide...
diysolarforum.com

Top Balancing LiFePo4 Cells using a low cost benchtop power supply.

To get the paper, click on the orange at the top of this page. This is a tutorial with detailed steps on how I top-balance my LiFePO4 Cells using a low-cost benchtop power supply. To get the tutorial, click on the orange "Download" button...
diysolarforum.com diysolarforum.com
Click to expand...
The cables came with the tester, they are joined at the origin, there is no separate connection for the current and voltage leads
1671011087433.png
I could crimp some ring connectors and screw them to the terminal easily though
 
Ucatchmydrift said:
Its a 20w heating mat, and its JUST managing to keep the temp at about 14 degrees. Now have it set to come on at 12 degrees and go off at 15. Its been 0 degrees here in the day now for a couple of weeks, and - 5 at night. In a metal shed outside that has no insulation, and is damn cold in there, but the mat is doing a good job so far. Gunna get another incase it stops working. ?
Click to expand...

Working well then! A bit of PIR around and above will do wonders ? Mine are at 20 degrees in -1 degree garage with 15W heater ;)
 
SeaGal said:
Working well then! A bit of PIR around and above will do wonders ? Mine are at 20 degrees in -1 degree garage with 15W heater ;)
Click to expand...
Nice ?. Yep gunna invest in some, just incase we get some crazy cold weather like back in 2010 when it got down to -15 degs!
 
4 hours in, the terminals are getting quite warm, about 27 deg for the positive and 40 deg for the negative
battery at around 31 deg (measured on the side at half height); I'm using a cheap infrared thermometer

I'm slightly concerned that due to the heat produced ad the crocodile clips, not all the energy generated during discharge will be measured

1671019370234.png
 
All very interesting - but def need to replace the croc clips - terminal temps are not normal (but not surprising with those clips).

Keep us updated. I didn't measure our 280Ah cells capacities, but had to set the BMS cycle capacity to 300Ah to get meaningful SOC from it.
 
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