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> consider decoupling your battery charger setup from the solar portion Can you provide more details on this? I’m having a hard time imagining how the solar, i

by mapmap 3y ago

> consider decoupling your battery charger setup from the solar portion Can you provide more details on this? I’m having a hard time imagining how the solar, inverter, and battery chargers are connected in relation to the house and grid. And what is HA? Thank you.

jacquesm 3y ago
HA -> Home Assistant If you have a separate charger/inverter that you can control remotely using HA then you simply monitor your outgoing power and if that goes negative and your batteries aren't charged yet you instruct the charger portion to charge the batteries. Then, when the sun goes down you can order the inverter part to come to life and supply current up to the point where the outgoing current is close to zero. Like that you maximize your own usage. And by having this split up you can site your batteries in a spot where the temperature is relatively stable, but still outside of the house which is usually not where you have your solar panels. A solar inverter should be sited relatively close to the panels to avoid cable losses and to reduce the risk of having unfused 800V DC cabling running through your house for any appreciable length. Ideally you want those cables to be just long enough to get under the roof to the spot where the inverter sits and then regular cabling to the distribution panel. By connecting the charger/inverter combination to the distribution panel in the same manner you get a lot more freedom. And if you have multiple sets of solar panels that's really the only setup that makes sense otherwise only a limited number of panels can be used to charge the battery (the ones that are directly connected to the inverter that feeds that battery). That's why I'm not a huge fan of the so called 'hybrid' inverters. They make a lot of assumptions about the physical layout of the location that may not hold true in practice. Here I have 50 panels divided into five fields, 6,8,8,10, and 18 panels in each of them and three inverters. This gave a lot of flexibility in where panels could be located. But if I want to charge a battery in a hybrid setup I'd have to pick which set of panels to use and then I'd still be limited in where I could locate the batteries, presumably they'd be close to whichever set of panels I would like to use to charge them with. But by decoupling that and using the AC network as the bus I can put them pretty much anywhere that I can reach with another cable run into the distribution panel. That way all 50 panels can contribute to the charging. An interesting extra option is to run one more cable from the battery charger/inverter to the inverter port, that allows you to power a set of critical loads from battery power. But since the grid here is very reliable I won't be using that. hth, feel free to ask more.
- TrueDuality 3y ago
  I haven't heard of a setup like this before. It seems like you would be loosing a lot of efficiency having to translate the voltage to AC and back to DC to charge your batteries.
  - jacquesm 3y ago
    Not really, those inverters are 96-98% efficient.

by mapmap 3y ago

jacquesm 3y ago

HA -> Home Assistant If you have a separate charger/inverter that you can control remotely using HA then you simply monitor your outgoing power and if that goes negative and your batteries aren't charged yet you instruct the charger portion to charge the batteries. Then, when the sun goes down you can order the inverter part to come to life and supply current up to the point where the outgoing current is close to zero. Like that you maximize your own usage. And by having this split up you can site your batteries in a spot where the temperature is relatively stable, but still outside of the house which is usually not where you have your solar panels. A solar inverter should be sited relatively close to the panels to avoid cable losses and to reduce the risk of having unfused 800V DC cabling running through your house for any appreciable length. Ideally you want those cables to be just long enough to get under the roof to the spot where the inverter sits and then regular cabling to the distribution panel. By connecting the charger/inverter combination to the distribution panel in the same manner you get a lot more freedom. And if you have multiple sets of solar panels that's really the only setup that makes sense otherwise only a limited number of panels can be used to charge the battery (the ones that are directly connected to the inverter that feeds that battery). That's why I'm not a huge fan of the so called 'hybrid' inverters. They make a lot of assumptions about the physical layout of the location that may not hold true in practice. Here I have 50 panels divided into five fields, 6,8,8,10, and 18 panels in each of them and three inverters. This gave a lot of flexibility in where panels could be located. But if I want to charge a battery in a hybrid setup I'd have to pick which set of panels to use and then I'd still be limited in where I could locate the batteries, presumably they'd be close to whichever set of panels I would like to use to charge them with. But by decoupling that and using the AC network as the bus I can put them pretty much anywhere that I can reach with another cable run into the distribution panel. That way all 50 panels can contribute to the charging. An interesting extra option is to run one more cable from the battery charger/inverter to the inverter port, that allows you to power a set of critical loads from battery power. But since the grid here is very reliable I won't be using that. hth, feel free to ask more.

TrueDuality 3y ago
I haven't heard of a setup like this before. It seems like you would be loosing a lot of efficiency having to translate the voltage to AC and back to DC to charge your batteries.
- jacquesm 3y ago
  Not really, those inverters are 96-98% efficient.