Mark Tinka wrote:
On 1/18/22 00:26, Jordan wrote:
Wow, that's a nice program. Do you know what they keep the "reserve percentage" set to, the proportion of stored energy that will never be discharged for grid-support, but held back for island-mode use in case of an outage?
I don't use the Tesla Powerwall, but Li-Ion is generally the same regardless of who packages it. The difference will be what the OEM decides to set the low-voltage cut-off to on the inverter and/or BMS.
I'm not sure how much the owner can configure a Tesla Powerwall, but with other installations, you can decide when your battery kicks in to run loads, or when it hands back to the grid or generator. This assumes evening time, when solar irradiation is unavailable, of course, as that is generally the preferred source of energy.
Now how about some programming available so you can decide what thresholds and conditions remote start your genny which powers the rectifier which substitutes|augments the solar array? All those 6500 PS lying about would make awesome rectifiers..... Joe
I've heard that Tesla will monitor the weather in your area to "pre-charge" the Powerwall to account for possible power disruptions. While I find that rather invasive, it's a cool feature for folk who "don't want to know". Then again, I also hear that Tesla will limit or withhold support and/or warranty if you do not connect your Powerwall to the Internet for them to "manage". The downside I hear, with that, is that they can remotely adjust SoH (state of health) thresholds to lengthen battery life in order to meet warranty promises. Not sure how true that is, but I've heard it a lot.
In terms of "reserve" capacity, Li-Ion can go much deeper than Lead Acid. Some inverters are setup to disconnect the battery anywhere between 3% - 20% SoC, depending on the OEM. For LFP chemistries, the BMS will usually turn the pack off at 2.50V, while for NMC, that will be around 2.75V. But different battery OEM's may be more or less aggressive with their BMS's, depending on who you choose to buy from.
Mark.