Solis noisy when topping dyness batteries to reserve soc

djr

Hi

Recently got solar installed. Solis inverter, 2 x 5kw dyness. I noticed the other day that the 2nd battery was switched off by the installer, I guess because we are not load shifting as we are still on a reversible meter. I switched it back on, and it's online ok. What I have noticed now however is that when the battery dips below 20%, the inverter kicks in and tops it up from mains. This wasn't an issue with the single battery connected, as the power draw from mains for the forcecharge was low, but now that both batteries are enabled, when the forcecharge kicks in the inverter gets very loud. Not an issue during the day, but at night very noticeable, and has woken me up repeatedly.

I can see two options, correct me if I'm wrong.

- disable 2nd battery to reduce mains power draw during forcecharge, but does this introduce a risk of battery degradation? My system is in the garage, attached but external to the house, so is cold in this season.

- limit forcecharge power which is currently set to 5000w

Thanks muchly 👍

Jonathan

https://www.boards.ie/discussion/2058329665/solis-noisy-when-topping-dyness-batteries-to-reserve-soc

You can drop down the force charge power. Drop it down to 2500W and the inverter whine will go away.

djr

https://www.boards.ie/discussion/comment/121573243#Comment_121573243

Cheers Johnathan, that did the trick. I guess it wasn't an issue when the 2nd battery was switched off, and not charging at all. Another Q battery question if you know the answer, am i better off having that 2nd battery off permanently until the solar picks up in spring and i'm able to charge it that way, or would it be better to fully charge both batteries to 80/85% once a week and let them run to 20%?

yankinlk

i think its bad to leave any battery off permanently. are u not using that much daily? 10Kwh? If you arent using at least 10/day then you would be MUCH better off sellling that 2nd battery. I assume it fills one first then the second one.

djr

https://www.boards.ie/discussion/comment/121575704#Comment_121575704

We use about 12-15kW daily, so once we have the battery charging off solar on the brighter days, I think it will be worth it. Our base load averages around 400-500w (wifi APs, fridge, nas, ISP, freezer etc).

slave1

A separate matter is that base load, v similar here and goes between 100-200w...

DC999

https://www.boards.ie/discussion/comment/121767205#Comment_121767205

As slave says, look at what’s using that 400-500w baseload. 500w constant is 12kWh a day or €1300 quid a year (on a 30c rate per kWh, simplistic calc of course!). Our whole house uses 8kWh a day (ex heating and cooking and EV). You’ve solar and batteries, so combine that with cutting down on using power and the pay back will be faster.

Our baseload when we’re on hols is 1.5kWh a day (fridge, freezer, modem, house alarm).

Not gloating, just giving a comparison of usage. 

slave1

Server, fridge/freezer, another freezer, router, hubs, wifi mesh units, clock radios, amps/TVs on standby, never more than 200w

djr

https://www.boards.ie/discussion/comment/121770427#Comment_121770427

thanks lads. i've set up home assistant which is talking to the eddi and inverter. i've added a few tuya plugs for the fridge, freezer and a bit of the always on gear to try and figure out what's consuming so much. all my lights are LED, fridge cycles between about 40-190w during the day, but yeah the base load has me concerned. i'll keep digging, i'm determined to get to the bottom of it. 'tea station' is a water boiler device we got to stop using the kettle so much. it boils and then maintains the water in an insulated tank for not much power.

slave1

Your battery (or in combination with active PV) should cover kettle boiling. I only have 3.1kW power from my battery so it's a simple case of boiling the kettle before using the toaster or hob and all good. I've used 4 days units so far in 2024, kettle gets boiled around 6/7 times a day

djr

https://www.boards.ie/discussion/comment/121770592#Comment_121770592

i'm guessing you've got solar in that case, and it's a large south-facing array? we've got 4.3 e-w and a 10kW battery, but the battery isn't getting up past 40% at the moment due to the low sun this time of year.

slave1

I have solar but that does nothing this time of the year, or very little in any case, used 3 day units in Jan which is the worst month, I charge by battery pack to 100% every night

djr

https://www.boards.ie/discussion/comment/121770708#Comment_121770708

ah. yeah, we've gotten a few 5-6kW days now with solar with the weather being OK on or off in Dublin, this is our first spring having it installed. i still have an old reversible meter, so can't do night charging at the moment unfortunately, but that sure would help a lot if i could.

DC999

https://www.boards.ie/discussion/comment/121770734#Comment_121770734

I'm deffo off topic here. Turn your battery off for now while you have a backwards meter. Just wear and tear when not needed.

But you'll save money when you move to a smart meter and charge the battery to full each night from.chewp night rate and load shift. Run the house from the battery. Export for FIT of 20c+ per unit. And reduce the baseload - which you're tackling now.

on_the_roots

https://www.boards.ie/discussion/comment/121770427#Comment_121770427

I have fridge/freezer, router, surveillance system, heat pump and air-tight ventilation system 24/7 and they all consume somewhere between 300 to 500 constantly. Also in cold days the anti-freeze on the HP kicks in regularly.