iBoost vs battery conflict

Hello, I had my system commissioned yesterday and am monitoring the portal like its going out of fashion 🙂

I have noticed that my iBoost is causing my battery to discharge, however it should only be running when excess solar is being generated (after the battery is 100%)

My battery is currently sat at 85% but is discharging to provide power to the iBoost.

I read in the manual I downloaded that I may have to fiddle with the threshold wattage at which it senses electricity being exported? Has anyone else had this issue at all?

Many thanks 🙂

Ra My neighbour had a similar issue, it turned out when she had smart meters fitted, they put the CT clamp back on backwards so was detecting import as export and just drained the battery.

The iboost or any other solar diverter shouldn’t cause a battery discharge.

I have an immersun on mine and I have noticed that in some circumstances it will grab the exported power rather than the battery - cloudy days are a prime example. But I’ve never seen it pull from the battery.

I have mine look for 50W of export - I seem to recall but could easily be wrong that that iboost is set for 0w. Though you have timers I think as well to mess with. I don’t have that on mine. (That I’ve found!)

If its an older iBoost pre Apr 2017, they dont play well with batteries. They have the same export threshold as the battery, so fight for the export.

I got a Sender 250, which helped, but still not brilliant. You need to set if a newer iBoost a threshold of 250W and delay of at least 10 seconds

I got a (cheap) Solic 200 before my battery was delivered and for while I was doing some plumbing and had the gas boiler decommissioned. It doesn't have the option to set thresholds and can hog battery output.

This tends to occur after a significant load has ceased, e.g the kettle. Once that happens, the diverter quickly grabs the export as the inverter overshoots, then the inverter sees the diverter as a valid load and continues to supply it from the battery.

What I'm doing to counteract this it to limit the maximum discharge power of the battery while the inverter is charging it.

I'm reasonably happy with this compromise, but am interested to see how well the expected GivEnergy diverter will integrate with the rest of the system when it's available.

Thanks for all your replies, it is a brand new system so I would hope the iBoost isn't one of the problematic older models.

I will check the CT clamp when I get home and make sure thats the right way around, the iBoost has been fitted out of the box and the system settings have not been altered afaik.

Will let you know!!

Many thanks 🙂

Ra if it's a new iboost+ - then as said above, you can set the threshold to be higher - say 200 or 250W. That's what I do - it plays nicely. It does sometimes grab the surplus for bit, but it's not an issue generally.

I find that on days when the clouds are there and then not there, i.e. rapidly varying solar panel output, our iBoost will react faster than the GiVenergy unit and grab the solar output which I would prefer to be charging the batteries. Haven't seen it start to use battery power though. However, I could see that happening, tbh.

I tend to turn the immersion off on "sunny interval" days until the batteries are at 100%, then let the iBoost take whatever it wants.

And yes, I have increased the iBoost threshold to 300W. Doesn't seem to help.

wilfleek Along similar lines, I have to set the Zappi to at least a 30 second start timer. I can't set it to a 10 second start time or it reacts faster than the Givenergy system. The speed of the Givenergy system reacting to changes in solar and house load would be my biggest complaint.

wilfleek When I get home I'll take a look at what it is up to. It seems to have settled now, I assume the hot water tank is full so the iBoost has been taken out of the equation.

Does it actually stop the battery charging though - although I sometimes see the iBoost react faster and take the surplus initially - it seems to allow the inverter to take over as that reacts to the surplus - quite how I've never quite fathomed - but given the battery always charges up to 100% off the solar even when I see the iboost taking charge, it works. Try leaving it for the day and see what happens

I've just looked at mine and today the sun has been rubbish - 12.8kWh - battery has taken in 5.4kWh and the Immersun diverter 0.58kWh - Actually I just watched it grab some energy and then slowly drop back to zero.
Grid import 0.3kWh and export 0.2kWh Give or take.
So I'm happy that with a 50W limit setting its working well with the battery. 🙂

I have a solarimmersion controller ten years old controlling two immersion heaters as it can do that and was in conflict mode with the batteries. Having set the export threshold to 200 watts all is working as it should . initially i could see an overshoot from the battery ie if 3kw kettle was used at the point of shut off the batterys failed to pull back supply quickly enough and a surge of export 100 watts or so would be detected then as the immersion controller grabbed the export the batterys seem to think my immersion unit was demanding power and ramp up to 3kw until satisfied or the batterys ran out ! The 200 watt setting has put the problem to bed 😄

JohnDawson is the 10 yr old controller called SolarCache+

no just googled solarimmersion

sparky77 my unit was by solarimmersion.co.uk and if i remember they were made in Milton keynes but it dont seem to be there anymore 🙁

Yes.
Adjusting your threshold is easy way to sort this.
I did go to 400w to prevent runaway discharge from battery. I was getting battery discharges even with 300w threshold. Unfortunately GE inverter is not Uber quick (most likely all other manufacturers) to ramp down when we switch of high power devices, this gets sensed by the iBoost as export and the runaway train starts.

all i done with my system is
put a contactor inline with my controller x2 3kw
gv energy charge first
if solar pv exceeds 3kw the contactor clicks in charging up the immersion
okay in the summer months need a better solution in the winter.
not sure whats the best way of charging both immersion and battery, order of charge, or both charging at the same time
pv on the roof is 10kw so charging immersion after 3kw of sun is not a problem in summer
even today cloudy battery 8.2kw (charged 5.1kwh) to full by 12pm, then immersion fully charged by 3pm at 71c

I thought the new battery does that when set up, something to do with balancing the cells. Ask Givenergy.
on a new system, saw a few videos on it still waiting for my system.

The immersun I have is the more expensive one and meant to play nice with batteries- and to be fair I have seen it being ok nearly all the time - not enough to worry about - total export today is 0.2kWh
Total solar diversion 1.19kWh - I wasn't at home today so don't know what the weather was doing - but there are a couple of times that it grabbed on a bit longer than would perhaps be ideal. But I can live with it.

numbers remove duplicates

mine is playing nice now, moved the immersion CT clamp close to the incomming supply
https://pasteboard.co/juaOMzAgm0m5.png
https://pasteboard.co/2rl4RyWkZtKS.png

add an image
add an image

add a image does not work for me/ linked them instead

Just an update for everyone here who has been kind enough to chip in; I adjusted my export detection to 200W and it seems to be behaving quite well at the moment. As others have mentioned there is the odd, short spike when high demand devices switch on/off but I can live with it as it is now. Have managed to pop in over 32kW of juice into my hot water tank in 6 days 🙂

Is it not a combination of the export excess value AND a suitable time delay that the iBoost needs to be configured for?

If the GE inverter takes say 20 seconds to back off when a large load is switched off, then the IBoost needs to be configured for a delay of 30 seconds before it starts to divert to the immersion having seen/detected the export excess.

Simon_C
The iBoost cannot be configured to have a time delay. it works be detecting when export levels reach a certain threshold.

Raising the threshold to 200W or higher. The threshold can be adjusted in 50W increments up to a maximum level of 500W (I believe that this applies to iBoosts made after May 2019).

So the MyEnergi Eddi immersion diverter is more capable, as it can be programmed with both an export excess and a time delay.

I just expected more capability from the iBoost than it actually has.

Simon_C
They are completely different products with different specifications from different companies.

The Eddie is also one third more expensive than the iBoost (£299 vs £395). It's also out of stock everywhere.

Apples and oranges.

I have an 8 year old Solarimmersion, and 1 day old Giv system. Just trying to get he Solarimmersion to play. I have had it on 20w excess for years and am trying 105w, but it was pulling from the battery after they charged over night. Will up export to 200w limit and see how that goes.

Also need to check my current clamp is the right way round after the battery install...

chocolatetrees I originally ordered the "older" style immersion - but when they couldn't deliver for a while due to stock, but had the later version (And more expensive) in stock. Which I went for - and does play quite well with the batteries - I've never seen it pull from the battery and not often taking precedence - looking at the power it takes its not a lot. And I have it set for 50w export. 100W and it definitely doesn't nick abit of battery charge - but there is a bit more export then. So have reverted back to the default 50w.