tag:blogger.com,1999:blog-3993498847203183398.post7040612949067011731..comments2024-03-28T09:19:27.451+00:00Comments on RevK<sup>®</sup>'s ramblings: Battery, part 3RevKhttp://www.blogger.com/profile/12369263214193333422noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-3993498847203183398.post-12064429100247020142022-09-09T11:57:07.079+01:002022-09-09T11:57:07.079+01:00I have had switchovers that we haven’t noticed - a...I have had switchovers that we haven’t noticed - as reported by the App. The Gateway will also disconnect the home from the Grid if there is an under/over voltage or frequency issue. It monitors the Grid output for 5 minutes before reverting back to the Grid. Tesla Netherlands has a record of the voltage that the Tesla is recording. This, along with smart meter voltage data, was enough to get my DNO to tap my local transformer.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-75518741492573363352022-09-07T22:54:38.308+01:002022-09-07T22:54:38.308+01:00The test was done in the face of a rather heavy lo...The test was done in the face of a rather heavy load, not certain why this would make such a difference as it usually is a very swift change over. If the battery was in a high charge condition and had to swap to a heavy discharge, then, due to battery protection, this could extend the timings.Andy Greennoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-61333568383651418102022-09-07T20:02:43.678+01:002022-09-07T20:02:43.678+01:00My house was built in 2018 and has a combi boiler ...My house was built in 2018 and has a combi boiler with no hot cylinder, as do all the other houses on the estate. Handy for storage space but not so much for heat storage…Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-30446869663866435052022-09-07T16:39:56.840+01:002022-09-07T16:39:56.840+01:00I'm not surprised about the cutout time on a r...I'm not surprised about the cutout time on a real power cut although nice to have it confirmed.<br /><br />Not sure that seamless transition is possible on a Lithium-Ion battery system which is even vaguely affordable for a domestic install.<br /><br />If you think about it in terms of UPS systems (which are primarily lead-acid cells) you'd have to run the supply through the Tesla unit continuously to ensure supply continuity. That's a big no-no for lithium cells unless you have deep enough pockets to replace them every 5 years.<br /><br />I'd also be concerned about running inductive loads such as your dryer off the battery as those are generally "problematic" loads for battery/invertor systems.<br /><br />You should definitely be dumping excess solar power into hot water tanks as its very efficient assuming a modern hot water tank. As an aside thats why building regs from 2012 onwards specify a hot water tank for new builds rather than a combi boiler - it can subsequently be used for heat pumps and/or PV solar systems. If your hot water tank is more than 10 years old then I'd put that on your list of things to do as it'll pay for itself very rapidly given you already have an excess of solar PV.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-90259283244842572082022-09-07T16:35:29.267+01:002022-09-07T16:35:29.267+01:00I believe from a spec point of view in an outage t...I believe from a spec point of view in an outage the gateway is supposed to open the grid contactor within about 30ms, and the powerwall begin off-grid operation within a further 25ms, so should all happen in well under 100ms, which most modern devices won't notice.<br /><br />Certainly with mine it seems to be immediate, at least when we tested at commissioning with a kettle boiling to use some power, and then using the grid isolator to kill the incoming supply, other than a noise from the gateway (presumably the contactor) there was no change, all my kit kept running fine etc...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-71024397880405746772022-09-07T15:51:41.943+01:002022-09-07T15:51:41.943+01:00I do not (yet) have an easy way to control that, a...I do not (yet) have an easy way to control that, and I don't think it would be as instant as needed. But, yes, longer term, scheduling when the hot tub is on is a factor.RevKhttps://www.blogger.com/profile/12369263214193333422noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-84853055798891181062022-09-07T15:50:02.259+01:002022-09-07T15:50:02.259+01:00You also have a hot tub. That'll sink some exc...You also have a hot tub. That'll sink some excess power in an off-grid scenario.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-77698973654129285912022-09-07T15:40:30.896+01:002022-09-07T15:40:30.896+01:00Ah interesting about the cutover time on power cut...Ah interesting about the cutover time on power cuts, I assumed they would have been able to make it almost seamless but still comply with the regs. I just bought an ME3000SP which has an emergency power supply (EPS) output, I thought that was a permanent supply output but it looks like that output is only active when the incoming supply fails, and you need to fit an external changeover relay if you want something permanently powered (ie. UPS-style).<br />Garethhttps://www.blogger.com/profile/02575622887669793171noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-81872026259741873492022-09-07T15:19:59.210+01:002022-09-07T15:19:59.210+01:00I have a hot tank, and even an immersion heater, b...I have a hot tank, and even an immersion heater, but not set up to sink excess power. It was a consideration to avoid export, but an interesting idea for handling excess battery charge from solar. That could work if I can get the real time data and switch it.RevKhttps://www.blogger.com/profile/12369263214193333422noreply@blogger.comtag:blogger.com,1999:blog-3993498847203183398.post-80697514856701163962022-09-07T15:18:23.733+01:002022-09-07T15:18:23.733+01:00Do you have a hot water tank to absorb any excess ...Do you have a hot water tank to absorb any excess you can't use otherwise?JJhttps://www.blogger.com/profile/15638774441452806449noreply@blogger.com