DC Discharge option MIA

Since I'm on IOG, I used to use the "DC Discharge" option on my AC3/gen2 9.5kwh battery, so that my battery would gradually discharge over the course of a day and wouldn't get charged back up again to 100% by any excess solar. I would then recharge it overnight on cheap off-peak electricity. This strategy both maximised my export and avoided my battery sitting at 100% for much of the time.

Although the DC Discharge option used to exist in the app, it was removed a few years ago, so I'd access it via the web dashboard instead.

A while back I noticed that the desired DC Discharge behaviour had stopped working. I tried switching DC Discharge off and on again, but it didn't seem to work. Now the DC Discharge option seems to have disappeared entirely from the web dashboard.

Does anyone know what's going on? Is existing functionality being hollowed out to go behind the upcoming subscription?

MrWobling the DC discharge option on the Gen 1 hybrid and AC 3 inverters didn't work all that logically and was resulting in a lot of confusion for users so this is why it was supressed in the app, but with the workaround as you were using in the portal.

I suspect the portal functionality has now caught up with the app.

The inverter firmware hasn't changed so you can use any of the 3rd party inverter control mechanisms described elsewhere on this forum to set the DC discharge if you still want to use it

MrWobling avoided my battery sitting at 100%

It is very important that the battery sits at 100%, as that is the only state where the cells can be balanced. As a rule of thumb, GivEnergy batteries should spend at least 10% of the time at 100% (i.e. 3 hours a day).

If the cells are allowed to get out of balance, the battery may become unusable.

Rubikcube However this does depend on BMS firmware* - from memory pre-3018 does any cell balancing at the low-end of the SoC (below 40% or 20% IIRC). Problem is it requires an idle battery to do cell balancing.

3015 certainly behaves this way, can't vouch for any of the rest of them. Let it drop to cutoff (4%), leave it for 1-3 hours and it'll rebalance the cells such that anything from 3-6% of the SoC will be recovered. Let that discharge to cutoff and you're at the "proper" 4% SoC level.

Doesn't do that at the top end.

*and probably inverter f/w

Just went to check FW versions. Battery is still on 3015.

Tried to opt out of production FW updates, on the basis of "if it ain't broke, don't fix it", but the switch to opt out of production FW updates is now disabled. 😰

Rubikcube good point - but this does happen most days after charging over night. I charge at 1.7kw overnight, which is just enough if the battery is deeply discharged, but most days, it's only charging from ₅₀+%, so it sits at 100% for a while.

MrWobling It was never enabled.