Electrics

From sciencedirect.com

Irreversible Changes of Active Material Caused by Deep Discharge
Deep discharge of batteries often leads to mechanical stresses in the plates, which leads to shedding, poor conductivity, and a diminished lifetime of the system. The active material utilization of a battery is therefore a trade-off against lifetime. Extensive volume changes and crystallographic structure changes during charge and discharge are the most common causes of mechanical stress in battery active materials. In addition, extreme voltages at the end of charge and discharge may initiate unwanted electrode reactions (such as corrosion) and other undesirable reactions (such as gas evolution).

An excellent source of info is https://www.sciencedirect.com/topics/engineering/deep-discharge
The most common are lead acid batteries and lithium ion.

In the lead acid range there are three common constructions
1. Liquid Electrolyte: The common car battery
2. Gell Electrolyte: Designed with the sulfuric acid in a gel form so it will nor spill
3. AGM: Where the acid although still liquid is held in a glass matt. The advantage is that unlike the gel it is quicker to charge and can take a heavier load due to the mobility of the electrolye. It is permanenlty sealed and can be used in extremely mobile instances as can the gel.

The above are also in order of expense.

Lithium Ion there are many variations the most coom being LiFePo (Lithium Iron Pohosphate)

The advantages are
1. the charging rate can be variable as the cells do not need to be fully charged.
2. They are very light weight an
3. can be used in anu porientation.
4. No sulfation.

The disadvantages are
1. initial cost
2. They don't last longer than a well looked after lead acid.
3. They are more environmentally difficult to recycle.

Given the above although I had considered using an LIFePo even a poorly looked after lead acid may work out a) cheaper and b) more benign to recyle.

30th November : ML V=12.64   Y=70Wh
29th November : ML V=12.67⇖Y=490Wh    I 
28th November : ML V=12.69⇖Y=90Wh
27th November : ML V=12.60⇖Y=160Wh
26th November : ML V=12.64⇖Y=610Wh    I 
25th November : ML V=12.56⇖Y=220Wh
24th November : ML V=12.56⇖Y=100Wh
23rd November : ML V=12.59⇖Y=110Wh
22nd November: ML V=12.63⇖Y=80Wh
21st November : ML V=12.57⇖Y=50Wh
20th November : ML V=12.54⇖Y=40Wh
19th November : ML V=12.51⇖Y=260Wh
18th November : ML V=12.53⇖Y=70Wh
17th November : ML V=12.59⇖Y=20Wh
16th November : ML V=12.67⇖Y=110Wh
15th November : ML V=12.51⇖Y=190Wh
14th November : ML V=12.69⇖Y=10Wh
13th November : ML V=12.63⇖Y=330Wh
12th November : ML V=12.51⇖Y=230Wh
11th November : ML V=12.67⇖Y=30Wh
10th November : ML V=12.51⇖Y=250Wh
9th November ::: ML V=12.59⇖Y=60Wh
8th November ::: ML V=12.67⇖Y=90Wh
7th November ::: ML V=12.67⇖Y=140Wh
6th November ::: ML V=12.61⇖Y=530Wh    I 
5th November ::: ML V=12.60⇖Y=660Wh    I 
4th November ::: ML V=12.60⇖Y=340Wh    I 
3rd November ::: ML V=12.67⇖Y=170Wh
2nd November :: ML V=12.54⇖Y=240Wh
1st November ::: ML V=12.67⇖Y=50Wh

From the batteries 12 volts is fed to a mash-up via 16㎜² (110A)

The first port of call is a fuse box, from which currently there are three loads.

The main load is the ring-main to the main room. This goes via 20A fuse to a small distribution box in the main room, from which it goes to another distribution box by the computer station.

Nov 20th

Sadly the jaws on the Nipex do not meet and the bevel of the 'cutting' edge is so shallow that it is more like a crimper. Farnell are refunding me the cost and leaving me with the duff tool as it is not worth the returns cost etc.