Solar panels and battery - any real world recommendations?

Ron-ski said:
Apparently it's not good for the batteries to be stored at 100%, LifoPO4 should be stored long term around 30 to 50% SOC, but this does vary for different chemistries.

I've no idea if cycling 85 to 100% daily is bad or not, and if you Google it there will be a multitude of opposing opinions.
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Yeah is seems to say doing it daily is ok, but the battery’s shouldn’t be held at 100% for weeks at a time, which now makes me think how I should set it up when I go on holiday(4 weeks in Australia), my house draws about 150w on tick over, so I’m thinking and put a solar charge limit of 50-70% on the battery through the day then sell the rest to grid and turn off overnight charging of the battery, does that sound right ?
 
It will be fine, don’t worry about it.

I charge my battery to 100% and discharge it to 4-10% daily. It’s got a 10 year warranty and this cycle count falls well within the warranty terms.

Don’t forget the usable capacity is at most 90% of the total cell capacity to 0 isn’t really 0.

With how much battery prices have dropped in the last 3 years let alone 10 years and with even cheaper batteries on the horizon (sodium ion), what you have now will be long obsolete by the time it’s warranty is done.
 
the wopster said:
Yeah is seems to say doing it daily is ok, but the battery’s shouldn’t be held at 100% for weeks at a time, which now makes me think how I should set it up when I go on holiday(4 weeks in Australia), my house draws about 150w on tick over, so I’m thinking and put a solar charge limit of 50-70% on the battery through the day then sell the rest to grid and turn off overnight charging of the battery, does that sound right ?
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Sounds like a good plan, might as well treat it gently whilst away
 
Ron-ski said:
The cables shouldn't exit under a tile, the tile could chaff the insulation, and over time wear through the cable.

A proper cable entry should be used, such as this.

Dektite® Lead Multicable Solar Flashing (Tile or Slate Roof) DNLS10MB

Deks Multicable Solar Flashing - Lead DLNS10MB
midsummerwholesale.co.uk midsummerwholesale.co.uk
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Spoke to the installer today. He said "nobody uses these flashings". So I called MCS, who pointed me at IET. IET's guidelines are open to interpretation - it's OK as long as the wire has been tensioned and the roof is watertight. Anyway - I've asked for photos and will have a think about what to do next. Thanks for calling it out!
 
Are people aware intelligent go is changing come April? When charge slots are given for the car outside standard time, whole house will NOT be covered. Shame. This is the start I assume to moving home away from EV. Guess I ll be looking at another 30 panels for the east and north roof spaces along with an inverter upgrade.
 
Nathan said:
Are people aware intelligent go is changing come April? When charge slots are given for the car outside standard time, whole house will NOT be covered. Shame. This is the start I assume to moving home away from EV. Guess I ll be looking at another 30 panels for the east and north roof spaces along with an inverter upgrade.
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Not surprising but how can they differentiate what is using the power?
 
200sols said:
Not surprising but how can they differentiate what is using the power?
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Well they have access to your car and/or charger. So it will be a simple bit of maths with the smart meter data I guess. Wonder if we could hook up the EV whilst it’s on charge
 
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Nathan said:
Are people aware intelligent go is changing come April? When charge slots are given for the car outside standard time, whole house will NOT be covered. Shame. This is the start I assume to moving home away from EV. Guess I ll be looking at another 30 panels for the east and north roof spaces along with an inverter upgrade.
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Source please.
 
Nathan said:
Well they have access to your car and/or charger. So it will be a simple bit of maths with the smart meter data I guess. Wonder if we could hook up the EV whilst it’s on charge
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Where have you heard this, I'm on the Octopus forum and nothing's been mentioned on there that I've seen?
 
Marakith said:
Spoke to the installer today. He said "nobody uses these flashings". So I called MCS, who pointed me at IET. IET's guidelines are open to interpretation - it's OK as long as the wire has been tensioned and the roof is watertight. Anyway - I've asked for photos and will have a think about what to do next. Thanks for calling it out!
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MCS are useless, the only thing they exist for is to make money, very rare they will actually sort a problem out. Of course installers don't use them, they're in it to make profit, most customers won't know the difference, and probably won't even notice, that doesn't mean its the right way though.

What does "it's OK as long as the wire has been tensioned" mean? How is that going to stop the roof tiles chaffing the cable?

I have them on my roof, my installer back in 2015 wasn't going to use them, so I purchased them and they fitted them, I also purchased them when we installed the last set of panels.

I also saw them being used by an installer recently on Youtube, can't think who it was though.
 
Ron-ski said:
Where have you heard this, I'm on the Octopus forum and nothing's been mentioned on there that I've seen?
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github.com

Release Intelligent Octopus Go Fixes - v1.0.710 [IMPORTANT NOTE] · Webreaper/SolisAgileManager

Fixes an issue where new IOG tariffs weren't recognised correctly. Important Note about IOG Dispatch Charging As of April 2025 It seems that Octopus are introducing changes to their Intelligent Oct...
github.com github.com

From a programmer who works closely with Octopus. Been using his script over the last 12 months.

Shame, it was coming though! The way to counter this for me will be to increase my panels, especially if companies start hitting us with the overnight separation.
 
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@Nathan Its says from April 2025, we'll be in October 2025 in a couple days????

I've fixed mine for 12 months recently, so presumably they can't change mine even if it was the case.
 
Yeah I did see that and assumed a typo. I’m going to take a look at T and C now to see if I can see anything different. I hope it doesn’t change and I really like Octopus for the ease of use, price and CS.
 
That post coincided with the introduction of the Octopus Intelligent Drive Pack which is a £30/month for unlimited car charging (not house usage).
 
github.com

Impact of Octopus change to Intelligent Go Tariff · Issue #215 · Webreaper/SolisAgileManager

You may have missed a change that Octopus have made to their Inteligent Octopus Go tariff. In the April 25 T&Cs when you car is charging outside the cheap rate period, they only intend to apply the...
github.com github.com

Quote
Re-reading the T&C of the two sections below my understanding is that the 6 hour off-peak your EV charging and household usage is charged at the cheap rate 7p.

The change come with IOG dispatch slots outside of the 6 hour off-peak period, only EV is charged at 7p whilst household usage is charged at the higher rate.

I've contacted Octopus Energy for confirmation that the above is the case and for clearer wording in the T&C's.

2.4.1.3 The Intelligent Octopus Go tariff is for customers with a battery electric vehicle or plug-in hybrid vehicle that charges primarily at the home that we supply. Any electricity used by the vehicle according to the Intelligent Octopus Go schedule plus any other electricity used in your home during off-peak hours will be charged at the night rate.

2.4.1.4 If we schedule your electric vehicle to charge outside of the off-peak hours, we will apply the night rate for your EV charging and any underlying household usage will be charged in the relevant half hour billing periods.

Might be worth keeping an eye on bills, seems there has been no changes as of yet.
 
Thats not how I read it at all, both are charged at 7p.

2.4.1.3 The Intelligent Octopus Go tariff is for customers with a battery electric vehicle or plug-in hybrid vehicle that charges primarily at the home that we supply. Any electricity used by the vehicle according to the Intelligent Octopus Go schedule plus any other electricity used in your home during off-peak hours will be charged at the night rate.

Thsi clearly states all every in the off peak hours is always 7p - fine.

2.4.1.4 If we schedule your electric vehicle to charge outside of the off-peak hours, we will apply the night rate for your EV charging and any underlying household usage will be charged in the relevant half hour billing periods.

What this says is, if we charge your car outside of the off peak hours, they will apply the night rate for your EV AND your house during the 'relevent half hour period'. The 'relevent half hour period' is the fixed 30 min blocks which make up the day and its the whole half hour period if they carge your car for any amount of time during that period.

So if they charge your car for 6 mins from 19:12 to 19:18, you get 7p electrcity from 19:00 to 19:30. As above thats your EV and any other electicity use.


The issue here is people are not used to reading legal language and are not applying the correct meaning of 'and' which means the two things together apply at the same time. If your household energy was charge at the peak rate it would say something along the lines of:

2.4.1.4 If we schedule your electric vehicle to charge outside of the off-peak hours, we will apply the night rate for your EV charging for the relevant half hour billing periods and any underlying household usage will be charged at the day rate in the relevant half hour billing periods.
 
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Inteligent Go is too cheap and can be abused. IMHO sooner or later Octopus will change the terms, so only the EV gets cheap electricity during the day slots.

BTW the EcoFlow eBay shop has a 20% discount code on many items, e.g.:
https://www.ebay.co.uk/itm/317176882717 - EcoFlow Stream 800W Micro Inverter for £92
https://www.ebay.co.uk/itm/317147865563 - EcoFlow Refurbished STREAM Ultra 2000W Balcony Power Plant 1920Wh Solar battery for £714

I think two Stream Ultras (each has 4x MPPTs) + 8 solar panels will make a very capable solar system. As long as one can install the panels south-facing and not spend a ton of money on installation, such a system can easily pay off in 3 years.
 
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SkyTerran said:
Inteligent Go is too cheap and can be abused. IMHO sooner or later Octopus will change the terms, so only the EV gets cheap electricity during the day slots.
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It’s not too cheap but it can be easily abused.

You are missing that IOG is a demand flexibility service, the grid pay octopus to take electricity when there is surplus and to not take electricity when there is a shortage. Likewise for almost all users the house usage is tiny compared to what the car is using.

Arguing for the tariff to be watered down because it can be abused by a tiny proportion of users is a bit of an odd take.

Perhaps change the terms to clamp down on the abuse first?

E.g. require a 32A capable charger and it must be set to at least 30A. That will cut down on almost all the abuse.

If needed, they could set a cut off for a guaranteed ready time the ‘following’ morning e.g. 3am (stops people plugging in at 7am for a 11am ready time as I have done in the past).
 
Another way to stop the worst abuse is to set export rates lower during the cheap rate period, the very worst offenders charge and then export through out this period.

In over news I saw this posted on another forum, it appears very accurate.

Solar Wizard

solarwizard.org.uk solarwizard.org.uk
 
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