Posted by: @batalto

@derek-m what's the total capacity of that ups? How many Wh?

Hi Batalto,

It is 1500VA, which is 1500W at unity power factor, which would give 1.5kWh of storage.

@derek-m for £108?! You'll forgive me, but I don't believe that for a second.

Posted by: @batalto

@derek-m for £108?! You'll forgive me, but I don't believe that for a second.

Hi Batalto,

You don't have to believe me, go onto the UPS Centre website and see for yourself. The model I chose is the Powercool 1500VA (900W output) unit, at £90 + VAT.

@derek-m the stats I can find states

Battery Type

2 x 12V8AH Sealed Lead-Acid = 192Wh of storage

Maximum power 15-20mins depending on load. Which makes sense as 900 X 0.25 = 225w

XCASE.CO.UK "https://www.xcase.co.uk/products/powercool-1500va-smart-ups-900w-lcd-display-3-x-uk-plug-2-x-rj45-3-x-iec-usb"

X-Case

Hi @batalto

I bow to your greater knowledge. I obviously should have read the small print.

Posted by: @batalto

@derek-m the stats I can find states

Battery Type

2 x 12V8AH Sealed Lead-Acid = 192Wh of storage

Maximum power 15-20mins depending on load. Which makes sense as 900 X 0.25 = 225w

XCASE.CO.UK "https://www.xcase.co.uk/products/powercool-1500va-smart-ups-900w-lcd-display-3-x-uk-plug-2-x-rj45-3-x-iec-usb"

X-Case

Any idea how many years the batteries in these devices last?

Are they replaceable? 

@jeff it's just lead acid, so should last a while. That said, lead acid you can't really empty very well. They generally only have a 50% depth of discharge to keep them in any fit state - hence why they work well as a UPS

Hi @jeff

The manual states 2 to 5 years, and it would appear that they are replaceable.

Posted by: @alex

Thanks @Derek M - UPS does look like a good option for short term use for 1-2 laptops - looks like it could last a  hour or two- thanks for the idea. 

SMA sunny boy looks really interesting for switching to off-grid use when required for domestic PV. As with all these more interesting options- it's finding a trusted installer with the experience to do it that seems a challenge. I've contacted the company - so will see. 

I've also considered a stand alone system eg by sunshine solar - one of the companies reasonable rated by ethical consumer. I've seen people using the off-grid solar kits - eg 330w/24v/1kw storage kit- for Sheds/camper vans/garden offices - so it could work for laptops (with the right weather of course!). 

That may just keep the domestic installation simple. It's been challenging enough to get quotes so far without introducing unfamiliar components systems

@Mars good luck with your off grid plans. & thanks for your blog -  it's been really helpful reading about your experiences. 

Hi Alex,

Sorry, I did not read all the small print prior to replying earlier.

Thanks to Batalto's clarification, it would appear that this particular model would keep a laptop running for approximately 3 hours. There are larger capacity models available, but obviously these are more expensive.

@derek M no need for apologies at all. Thanks to you and @batalto for such a useful exchange. 

My studies around batteries have been sadly neglected! 

I hope the UPS will still serve well for you ASHP

I'm guessing because of what they're used for- & with @batalto  saying about them having 50% depth of charge they need to be plugged in (rather than being kept for a backup/in a cupboard per say). 

What I've understood from reading/talking to those installers I could:

Re the sonny boy SMA directed me to a page of the registered installers- they do have 6 in the UK. I have contacted the one near me to explore the options. 

For smart energy ( that can make use of dynamic pricing) with battery and inverter integrated sonnenbatterie  and powervault (eon testing these at present so the nationalgrid can draw from them when needed) are all options which can  (sonnenbatterie) or may be able to provide off grid supply. These are large batteries though >100kg >100cm in height and more expensive- minimum 4khw storage starting 4700. 

 They can't fit in the loft & a general installer said there were not easy to practically fit due to their weight. & practically  for me they won't fit in the understairs cupboard where the consumer unit is. May be an option for those who have a garage/cellar. 

Re flat roof: 

the fixing systems that require drilling into the roof risk leakages.  Ballast is a further option- though being on the top floor of a house increases windspeeds- so a little more risky. & obviously with more weight- puts strain on the underlying structure. We are perhaps in the 'is it worth it?' area

ethical consumer and which provided an interesting perspective on which solar pv manufacturers are more ethical and some good basic information for some one like me

Finally the solar panel market has gotten hugely busy. When I'm getting responses it's often we're only doing local/new build and when people do respond it's 2-3 weeks to do a quote currently. So it's good luck to those trying to get PV installed- and hats of to those of yo who already have!

Posted by: @alex

@derek M no need for apologies at all. Thanks to you and @batalto for such a useful exchange. 

My studies around batteries have been sadly neglected! 

I hope the UPS will still serve well for you ASHP

I'm guessing because of what they're used for- & with @batalto  saying about them having 50% depth of charge they need to be plugged in (rather than being kept for a backup/in a cupboard per say). 

What I've understood from reading/talking to those installers I could:

Re the sonny boy SMA directed me to a page of the registered installers- they do have 6 in the UK. I have contacted the one near me to explore the options. 

For smart energy ( that can make use of dynamic pricing) with battery and inverter integrated sonnenbatterie  and powervault (eon testing these at present so the nationalgrid can draw from them when needed) are all options which can  (sonnenbatterie) or may be able to provide off grid supply. These are large batteries though >100kg >100cm in height and more expensive- minimum 4khw storage starting 4700. 

 They can't fit in the loft & a general installer said there were not easy to practically fit due to their weight. & practically  for me they won't fit in the understairs cupboard where the consumer unit is. May be an option for those who have a garage/cellar. 

 

Re flat roof: 

the fixing systems that require drilling into the roof risk leakages.  Ballast is a further option- though being on the top floor of a house increases windspeeds- so a little more risky. & obviously with more weight- puts strain on the underlying structure. We are perhaps in the 'is it worth it?' area

 

ethical consumer and which provided an interesting perspective on which solar pv manufacturers are more ethical and some good basic information for some one like me

Finally the solar panel market has gotten hugely busy. When I'm getting responses it's often we're only doing local/new build and when people do respond it's 2-3 weeks to do a quote currently. So it's good luck to those trying to get PV installed- and hats of to those of yo who already have!

 

 

 

 

Hi Alex,

I am still awaiting the arrival of the UPS, which I hope will help smooth out the ups and downs of the power from the solar PV to the heat pump.

A UPS is designed to be connected to the mains supply when in use, with the output connected to the equipment to be kept operational during a power cut. In that way there is no loss of supply to the equipment when the mains supply is lost. If you wish to extend the operating period of the UPS during a power cut, I believe that some of the Powerwalker models can accommodate the installation of additional external batteries, though I have not delved into this aspect in detail.

@alex I would honestly consider just a generic battery, you'll get far more storage for your money. You can always change the charge controller/inverter in the future - which is the smart thing. £4700 for 4kwh is crazy. If you want to spend that you could easily get 30kwh