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Storage Batteries - How do you manage your system over the winter months?


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I have seen that a number of users have storage batteries installed. Given that winter often brings minimal charging via solar PV and most batteries have a cut off level (Li-ion around 10%) how do you manage your system over the winter months?

I began by raising the lower threshold above 10% but have recently been charging overnight about once every week but we’re still trying to understand the best way to make use of and maintain it all. 

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Best answer by Simon1D 4 December 2022, 14:19

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We're on a fixed rate so there's no point charging the battery overnight. We just leave the system running the same way as in the summer, charging from any spare solar. We haven't had a full battery since early October but we usually manage to get some charge.

Our minimum charge is 10% and that stays constant through the year.

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I have seen that a number of users have storage batteries installed. Given that winter often brings minimal charging via solar PV and most batteries have a cut off level (Li-ion around 10%) how do you manage your system over the winter months?

I began by raising the lower threshold above 10% but have recently been charging overnight about once every week but we’re still trying to understand the best way to make use of and maintain it all. 

Hi, I assume your on a tarrife like Econamy 7 that gives you a cheaper night rate?

To give an informed reply it would be good to know what capacity your storage batteries are? Secondly what are you using the energy from thos batteries to power?

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I have seen that a number of users have storage batteries installed. …

Hi, To give an informed reply it would be good to know what capacity your storage batteries are? Secondly what are you using the energy from thos batteries to power?

Hi @rodman I was simply interested in what others do but our batteries are now 9.6kWh and we only power the home .. no EV or other attachments. 
Edit: we don’t have E7 or similar
 

@M.isterW I found that if our system doesn’t charge for a day or so the system drops below 10% (starting from a low level)

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I have seen that a number of users have storage batteries installed. …

Hi, To give an informed reply it would be good to know what capacity your storage batteries are? Secondly what are you using the energy from thos batteries to power?

Hi @rodman I was simply interested in what others do but our batteries are now 9.6kWh and we only power the home .. no EV or other attachments. 
Edit: we don’t have E7 or similar
 

@M.isterW I found that if our system doesn’t charge for a day or so the system drops below 10% (starting from a low level)

Hi, MisterW above has given you the best answer.

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If you pay that same for overnight electricity as day time electricity you're wasting money by charging overnight. You lose at least 10% on the charge/discharge so it's only worth charging from the grid if you have a cheap rate.

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If you pay that same for overnight electricity as day time electricity you're wasting money by charging overnight. You lose at least 10% on the charge/discharge so it's only worth charging from the grid if you have a cheap rate.

Hence my question. My batteries drop to 9 or 8% if I leave things as in summer and don’t charge from the grid as winter doesn’t charge enough .. unless I change the lower discharge level to 11 or 12%

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Don't you get any charge in winter?

 

Our inverter keeps the batteries at around 10 or 11%. It normally discharges and charges a tiny amount each day just to keep the battery at around 10%. Maybe you need to check your inverter settings.

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Don't you get any charge in winter?

 

Our inverter keeps the batteries at around 10 or 11%. It normally discharges and charges a tiny amount each day just to keep the battery at around 10%. Maybe you need to check your inverter settings.

Not much. 
The inverter is fine and if critical will initiate a charge from the grid but as I said to begin with, I wondered what others do. 
If your inverter manages things, that suggests that it does top up when needed

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Updated on 15/01/24 by Emmanuelle_OVO: 

OVO’s grid balancing scheme Power Move is now available for all eligible customers!

 

 

 

If you pay that same for overnight electricity as day time electricity you're wasting money by charging overnight. You lose at least 10% on the charge/discharge so it's only worth charging from the grid if you have a cheap rate.

An occasional exception to this would be if you’re eligible for one of these peak usage-shifting schemes.

(If Ovo don’t invite you to use theirs, Loop Energy is running one that’s open to all - albeit subject to them creaming off 20% and only paying you in Amaz*n vouchers, so not for me.)

Well worth using your battery (I don’t have one) to shift that load: shifted units effectively cost minus £1.90 /kWh for someone on the standard capped tariff.

Simon

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If you pay that same for overnight electricity as day time electricity you're wasting money by charging overnight. You lose at least 10% on the charge/discharge so it's only worth charging from the grid if you have a cheap rate.

An occasional exception to this would be if you’re eligible for one of these peak usage-shifting schemes.

(If Ovo don’t invite you to use theirs, Loop Energy is running one that’s open to all - albeit subject to them creaming off 20% and only paying you in Amaz*n vouchers, so not for me.)

Well worth using your battery (I don’t have one) to shift that load: shifted units effectively cost minus £1.90 /kWh for someone on the standard capped tariff.

Simon

Yes thanks @Simon1D   I’m using the Hugo version so do this.  They only ask for 25% reduction and the reward is cash .. although I’m not sure if there’s any payout until the end of the event

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Also you could charge up when the grid is running on wind power then use it when it’s a high carbon time. All you get is a warm feeling no cash benefit, but that’s something!

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I have been testing things out as you might have seen @juliamc 😁

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Rooky question as I still am in the process of deciding what to get pv and battery-wise: How can you get the battery to charge during low cost periods, then discharge at peak cost periods? Is this something that can be programmed into the system ? Does it depend on whatever app or inverter you have ?

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Rooky question as I still am in the process of deciding what to get pv and battery-wise: How can you get the battery to charge during low cost periods, then discharge at peak cost periods? Is this something that can be programmed into the system ? Does it depend on whatever app or inverter you have ?

Yes, my inverter (LuxPower) has settings which can automatically charge either at set times or at the lowest cost times (if you use a ToU tariff).

Since I started a month or so ago, my stats tell me that I’ve saved 45% compared to a standard tariff and these are always the greenest slots too

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That sounds perfect. How about switching to use the battery during peak hours rather than draw from the grid ? Can that be programmed in ?

 I’m wondering if solar is really going to make much of a dent in my electricity bill as most of the heat pump usage is in the winter months when the solar is a bit pathetic. Battery storage seems a better bet.

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That sounds perfect. How about switching to use the battery during peak hours rather than draw from the grid ? Can that be programmed in ?

 I’m wondering if solar is really going to make much of a dent in my electricity bill as most of the heat pump usage is in the winter months when the solar is a bit pathetic. Battery storage seems a better bet.

Battery certainly makes better use of solar. 
You can usually programme the inverter to feed the property (which should include the heat pump) before anything else and you can set ‘Charge Priority’ if you don’t want the battery to discharge at certain times which would ‘save’ its energy for peak if that’s what you want

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Thanks again BP - I have another question!!!

Assuming a 4kWp array, if I charged the car at the peak solar hours, using my PodPoint charger at 7kWh, I’d still be drawing the extra power from the grid. Rather than change my charger (seems extravagant) could I use a granny charger instead ?

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Thanks again BP - I have another question!!!

Assuming a 4kWp array, if I charged the car at the peak solar hours, using my PodPoint charger at 7kWh, I’d still be drawing the extra power from the grid. Rather than change my charger (seems extravagant) could I use a granny charger instead ?

Assuming no batteries, then you could or simply restrict the charge level (presuming you can) from your charger. You would need to calculate if the EV would be charged enough by when you need it

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Unfortunately the PodPoint doesn’t allow that, as far as I know….. it’s all or nothing ☹️

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