Seplos battery with solis inverter thoughts

[DocD]

I appreciate all the replies here thank you everyone 😊😊

[Dan F]

37 minutes ago, DocD said:

I don't know what's max for residential, but they email me today saying will need to upgrade/increase my fuse

 

So the only issue with G98 compliant is that the inverter would be 3.68kw? 

I'm looking at my bill and most of the day I'm always less than 1kw usage. Only goes over 3kw when charging car at night. Maybe 3.68kw inverter will be ok for my needs 

 

It probably goes over 3kW when you are doing more than one of: cooking, kettle, iron, washing machine etc, but that isn't that much of the day and everything under 3.68kW you would consume from a battery during those periods anyway, so yes, could still make sense.  Try to find 3.6kW, rather than 3kW though. 

 

 

[Originaltwist]

17 hours ago, Wil said:

Octopus Intelligent Go gives 7.5p from 23.30- 05.30

 

@Originaltwist are you the author of this website?

https://originaltwist.com/2018/11/14/diy-fan-coil-heater/

 

Yes - guilty as charged

[Dillsue]

12 hours ago, DocD said:

So the only issue with G98 compliant is that the inverter would be 3.68kw? 

I'm looking at my bill and most of the day I'm always less than 1kw usage. Only goes over 3kw when charging car at night. Maybe 3.68kw inverter will be ok for my needs 

If you avoid switching multiple loads on at once there's a fair chance you'll be able to stay under 3.68 kw for most of the time, but it can take a while to get into the swing of not switching everything on at once- 18 months for my wife to sort of get it!!

[DocD]

On 05/02/2024 at 22:45, Dan F said:

 

It probably goes over 3kW when you are doing more than one of: cooking, kettle, iron, washing machine etc, but that isn't that much of the day and everything under 3.68kW you would consume from a battery during those periods anyway, so yes, could still make sense.  Try to find 3.6kW, rather than 3kW though. 

 

 

Someone is saying that because it's a "battery only install" and no solar, it needs to be the solis 3kw AC coupled inverter, the 3.68kw inverter is DC and not suitable. 

 

Is this right? I can't have the 3.68kw inverter as battery only install? 

[Dan F]

3 hours ago, DocD said:

Someone is saying that because it's a "battery only install" and no solar, it needs to be the solis 3kw AC coupled inverter, the 3.68kw inverter is DC and not suitable. 

 

Is this right? I can't have the 3.68kw inverter as battery only install? 

 

The question is if it can be used without the solar panel input or not, all inverter/chargers use DC to charge/discharge battery.  I'd need to look at the datasheet/maunal to understand this, but there are other brands.. not just Solis.

 

[Dan F]

2 hours ago, Dan F said:

 

The question is if it can be used without the solar panel input or not, all inverter/chargers use DC to charge/discharge battery.  I'd need to look at the datasheet/maunal to understand this, but there are other brands.. not just Solis.

 

 

If you think about it hybrid inverters don't have any PV at night, so why wouldn't they work with without PV?  Best to check with manufacturers though.  I'd want to use a hybrid inverter if possible personally in order to have future possibility of adding some PV.

[DocD]

Are pylontech batteries any good? 

One installer says really good, another says full of problems 

[DocD]

Paired with 3.68kw hybrid solis inverter 

[Cooeyswell]

On 05/02/2024 at 19:47, Cooeyswell said:

 

I did look at 5kW inverters, most of these seem to be hybrids and cost around £500 more. Bizarrely several 5kW hybrids will only provide/source 3k to the battery (Growatt). They also (as mentioned) require a G99 sign-off prior to the install along with payment. G98 is a lot simpler.

 

I think this size gives the best "bang per buck" for my purposes. I am not attempting to cover all power consumption scenarios. From observation I expect to cover 80-90% of my peak usage with a 3kW system.

 

 

A quick follow up on this. After 5 days of operation I have used 5 units of peak electricity, all other usage has been successfully covered by the battery. I do see import from the grid when running high power items like the 3kW kettle, but this is relatively small in the scheme of things (~700W for 2 minutes). I also see import when an appliance exhibits "burst" behaviour - in my case both the induction hob and ovens - This appears to be due to the speed of response of the inverter as it ramps up to cover the demand over a few seconds. I assume I may be briefly exporting as the inverter ramps down as the load cuts off.

In my case the 3kW inverter is looking like the right choice.

Edited February 18 by Cooeyswell

[Homonid]

Hi DocD, I am also looking at installing Seplos batteries and am pondering which inverter to use, so I was wondering if you had any further thoughts to ad to this thread now that several months have passed?

Thanks.