Feasibility of Battery Backup/Generator for Boiler/CH/Hot Water etc

grumbler

ansaryon said:

The bad news is that the boiler wouldn't ignite, it went "click, click, click" but no flame was produced.

I'm pretty sure the click sound is produced by a spark. If so, the problem was with the solenoid valve.

Apodemus

grumbler said:

ansaryon said:

The bad news is that the boiler wouldn't ignite, it went "click, click, click" but no flame was produced.

I'm pretty sure the click sound is produced by a spark. If so, the problem was with the solenoid valve.

I know mine is not the same, being an oil burner, but I get rapid clicks if the photoelectric cell is failing to see a lit flame, rather than a buzzing if the igniter is not managing to light any fuel.  Not sure if the same applies in a gasburner.

Bendy_House

grumbler said:

ansaryon said:

The bad news is that the boiler wouldn't ignite, it went "click, click, click" but no flame was produced.

I'm pretty sure the click sound is produced by a spark. If so, the problem was with the solenoid valve.

Ah, that makes sense.

So you suspect the issue could have been caused by a weakly-activated gas valve? Guesswork, I know.

Apodemus

Bendy_House said:

Why would you want one that size? Just to have reserve power 'just in case'?

600W would theoretically draw 50A from your battery. Would there be a situation where you might do this?

Just tested the power needs of the old Rayburn - rises to 350 watts at start-up, then settles at 240W.  That is for both cooker and heating burners running at the same time.  CH circulation pump is just under 50W (it's on speed setting 2). Fuel pump motor is rated at 70W. I can't find a rating for the boiler fan, probably another 70W, which would leave about 50W for igniters, four solenoids, programmer, motorised valves etc

So that implies I need to cater for 1.5 amps output from an inverter, 30-35 amps draw on a 12 volt battery (allowing for inverter heat and fan).  

I wouldn't want to cheap-out on an inverter, and in the range I was looking at, the options were 300W or 600W.  So it looks like the 600W one would be the correct choice.

markin

No matter the VA rating a UPS seems to be designed for only around 20min So you would want to have a generator to power it and the ups just to give you time and smooth the power.

This model claims 25min - 174min, Without giving the wattage.
https://www.amazon.co.uk/APC-Back-UPS-2200VA-Uniterruptible/dp/B08G8XQC4H/


With led acid you can only safely use 40% so a 100AH car battery is really on 40AH.



'Solar generators' are basically a large capacity UPS that can be maintained/ Charged by grid or solar and come in all different sizes and price ranges.
https://forums.moneysavingexpert.com/discussion/6360585/portable-power-stations/p1

https://youtu.be/XEwhCDJp3os

Apodemus

markin said:

With led acid you can only safely use 40% so a 100AH car battery is really on 40AH.

Are you sure?  

Yuasa said:

Ampere-Hour Capacity at 20 Hour Rate (Ah) (EN50342.1 A1 Nov 2011 Item 5.1)

The Ampere-Hour Capacity measures the total amount of electricity stored in a battery.

An Ampere-Hour represents the amount of electricity when a current of 1 Ampere passes for 1 hour.

The Ampere-Hour Capacity varies with the rate at which the battery is discharged; the slower the discharge, the greater the amount of electricity that the battery will deliver.

The Ampere-Hour Capacity is the amount of electricity that a battery will deliver during 20 hours before the voltage falls to 10.50V. For example, a 60Ah battery will deliver a current of 3A for 20 hours.

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

grumbler

Apodemus said:

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

Also, this implies that it's fine to draw low power for 20 hours or higher power for shorter time. I don't see any reason for UPSs "to be designed for only around 20min".

Apodemus

grumbler said:

Apodemus said:

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

Also, this implies that it's fine to draw low power for 20 hours or higher power for shorter time. I don't see any reason for UPSs "to be designed for only around 20min".

I'm not sure that they actually are?  Certainly most of the ones I've used have continued working until either the battery has discharged or the power has come back on.  Working overseas with really dodgy power (huge voltage fluctuations, poor frequency control and frequent outages) we used UPS's on all our more sensitive equipment and were never aware of any 20 minute restriction.

markin

Apodemus said:

markin said:

With led acid you can only safely use 40% so a 100AH car battery is really on 40AH.

Are you sure?  

Yuasa said:

Ampere-Hour Capacity at 20 Hour Rate (Ah) (EN50342.1 A1 Nov 2011 Item 5.1)

The Ampere-Hour Capacity measures the total amount of electricity stored in a battery.

An Ampere-Hour represents the amount of electricity when a current of 1 Ampere passes for 1 hour.

The Ampere-Hour Capacity varies with the rate at which the battery is discharged; the slower the discharge, the greater the amount of electricity that the battery will deliver.

The Ampere-Hour Capacity is the amount of electricity that a battery will deliver during 20 hours before the voltage falls to 10.50V. For example, a 60Ah battery will deliver a current of 3A for 20 hours.

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

Apodemus said:

grumbler said:

Apodemus said:

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

Also, this implies that it's fine to draw low power for 20 hours or higher power for shorter time. I don't see any reason for UPSs "to be designed for only around 20min".

I'm not sure that they actually are?  Certainly most of the ones I've used have continued working until either the battery has discharged or the power has come back on.  Working overseas with really dodgy power (huge voltage fluctuations, poor frequency control and frequent outages) we used UPS's on all our more sensitive equipment and were never aware of any 20 minute restriction.

For the home market and the price point of under £300 its around 20min based on battery size and the average PC load, They are basically just meant to let you save your work and shutdown, Companies will happily spend thousands for huge enterprise systems to run work computers and servers.


I have the 950VA, So from the example chart given on the amazon page my low power 100w PC would last the 59min on the 2200VA model, So if the boiler was 120w that is how long the boiler would last, No good for a 24hr to 3 day power cut.


Many people have killed even the deep cycle batteries, If you want them to last more than a year you have to baby them, A friend managed to kill 6 AMG batteries, That was not a cheap mistake.

Apodemus

markin said:

Apodemus said:

markin said:

With led acid you can only safely use 40% so a 100AH car battery is really on 40AH.

Are you sure?  

Yuasa said:

Ampere-Hour Capacity at 20 Hour Rate (Ah) (EN50342.1 A1 Nov 2011 Item 5.1)

The Ampere-Hour Capacity measures the total amount of electricity stored in a battery.

An Ampere-Hour represents the amount of electricity when a current of 1 Ampere passes for 1 hour.

The Ampere-Hour Capacity varies with the rate at which the battery is discharged; the slower the discharge, the greater the amount of electricity that the battery will deliver.

The Ampere-Hour Capacity is the amount of electricity that a battery will deliver during 20 hours before the voltage falls to 10.50V. For example, a 60Ah battery will deliver a current of 3A for 20 hours.

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

Apodemus said:

grumbler said:

Apodemus said:

  That suggests that if you discharge your 100AH car battery at a low (DC) current, the figure is set to ensure that it only takes the voltage down to 10.5V, at which point it is still safely rechargeable.

Also, this implies that it's fine to draw low power for 20 hours or higher power for shorter time. I don't see any reason for UPSs "to be designed for only around 20min".

I'm not sure that they actually are?  Certainly most of the ones I've used have continued working until either the battery has discharged or the power has come back on.  Working overseas with really dodgy power (huge voltage fluctuations, poor frequency control and frequent outages) we used UPS's on all our more sensitive equipment and were never aware of any 20 minute restriction.

I have the 950VA, So from the example chart given on the amazon page my low power 100w PC would last the 59min on the 2200VA model, So if the boiler was 120w that is how long the boiler would last, No good for a 24hr to 3 day power cut.

I'm not sure that anyone had suggested that a UPS was a good option for a 24hour to 3 day power cut - we can all do the maths!

I had suggested using a UPS as a line conditioner on the output of a generator or on the output side of a low-quality inverter if a pure sine wave one was not available.