I was speaking about high voltage …and why I don’t use it…that’s all …
Why are people afraid of High Voltage Batteries?
- Thread starter jpwhit
- Start date
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 21,483
Bypass diode in PV panel prevents shaded section of cells from experiencing PV string Vmp in reverse bias.
Bypass diode across battery + BMS pack will do the same.
PV panels have a rated max voltage (relative to ground).
Battery will have similar, except they may not have thought to calculate, test, document it.
We're seeing 48V 50Ah lithium batteries for what, $350?
Biggest obstacle to me is BMS protocol. Perhaps it can be sniffed, reverse engineered, spoofed.
But inverter firmware may have a list of model numbers and Ah capacity, may not get everything from communications.
A couple BMS support multiple units in series. Batrium? REC can cascade up to 128s. But costs about $800 per 16s.
Nobodybusiness
Solar Sponge.
Last edited:
The forum is a great place to discuss battery voltages and options.
But this thread is discussing high voltage.
And reasons it is or isnt a good idea.
Low voltage is useless for a large load and lots of appliances.
No way to support several ac units, electric stoves, large lighting loads and big appliances on 12 or 24V
The wire costs would be astronomical.
Have any of you considered the DC arc on HV DC batteries, and what it takes to extinguish that arc??
PV has a very limited available fault current as compared to batteries! Especially Lithium batteries! The reason that they can be charged at way higher rates than lead acid batteries is the same reason that they can also produce way higher output currents than lead acid batteries! (When compared AH/AH)
Plus PV is generally not stringed at more than 2P. Usually the second string in parallel brings the available fault current up to the short circuit current rating. So you really shouldn't have more than 2 strings in parallel.
Example:
(12) HT 450w Bi-facial solar panels, stringed 6S2P, would give you 246.6Vmpp and a SCC of around 22Adc (plus a few amps from backside, if you wish). Total wattage rating of 5,400w. (Again, plus a little bit from backside, if you wish.)
A 5kWh battery at "48V" nominal (51.2V actual) could easily do a discharge of 100Adc (I'm referring to what the cells could handle, at least for short periods.) Short circuit current would be magnitudes higher!
A 5kWh battery at 400Vdc would be 12.5AH. Therefore going off of the same 1C discharge that I used for the 48V battery, this theoretical battery could easily push 12.5A for quite a while. HOWEVER, if you were to short circuit this 400V battery, you would get MUCH HIGHER amperage!! Plus, the voltage wouldn't dop to zero like it does with a PV short circuit!
What if we were talking about 30-60kWh of high voltage DC battery? Because really, that is where the high voltage battery argument shines, right? We would be talking 75-150AH.... Anybody wanna mess with 500-1,000Amps of fault current at 400Vdc??
My biggest point here is that when you have a short circuit on PV, the total power flowing drops off, and your voltage drops off as well. But you still get a pretty decent arc! But when you short circuit a battery (especially a lithium battery) your total power flow GOES UP!! And the voltage drops only minimally! I do realize that once you pull an arc from a breaker or other contact opening, the voltage rises up again. But PV is waaayyyy less potent in a short circuit condition than a battery!!
Another thing that factors into the whole debate around DC vs AC being "worse" at a given voltage is the fact that DC is a continuous current, where AC is not. AC is hitting zero amps 60 times each second (or 50 times, depending on where you live). That zero point every 17ms gives much more chance for an arc to get extinguished!
Anyone every done a short circuit test on solar panels at >100Vdc? That's a pretty serious arc! I did it just recently with ~120Vdc and ~20A short circuit current! Anyone care to try a short circuit test on a battery that is >100Vdc? If someone is brave enough to do this, please video it and show us the results!
By the way, here is a YouTube video by StyroPyro that shows some pretty serious DC arcing!
I don't think he runs very high voltage in that video unfortunately.... I couldn't remember from when I had watched it before, but just skimming through looks like maybe ~60-72Vdc or so. (5S or 6S at 12V??) (Though I don't think much higher voltage would be very safe, to be honest.)
So anyway.... Are any of you guys that are saying high voltage batteries aren't inherently more dangerous than high voltage PV up for the challenge??
PV has a very limited available fault current as compared to batteries! Especially Lithium batteries! The reason that they can be charged at way higher rates than lead acid batteries is the same reason that they can also produce way higher output currents than lead acid batteries! (When compared AH/AH)
Plus PV is generally not stringed at more than 2P. Usually the second string in parallel brings the available fault current up to the short circuit current rating. So you really shouldn't have more than 2 strings in parallel.
Example:
(12) HT 450w Bi-facial solar panels, stringed 6S2P, would give you 246.6Vmpp and a SCC of around 22Adc (plus a few amps from backside, if you wish). Total wattage rating of 5,400w. (Again, plus a little bit from backside, if you wish.)
A 5kWh battery at "48V" nominal (51.2V actual) could easily do a discharge of 100Adc (I'm referring to what the cells could handle, at least for short periods.) Short circuit current would be magnitudes higher!
A 5kWh battery at 400Vdc would be 12.5AH. Therefore going off of the same 1C discharge that I used for the 48V battery, this theoretical battery could easily push 12.5A for quite a while. HOWEVER, if you were to short circuit this 400V battery, you would get MUCH HIGHER amperage!! Plus, the voltage wouldn't dop to zero like it does with a PV short circuit!
What if we were talking about 30-60kWh of high voltage DC battery? Because really, that is where the high voltage battery argument shines, right? We would be talking 75-150AH.... Anybody wanna mess with 500-1,000Amps of fault current at 400Vdc??
My biggest point here is that when you have a short circuit on PV, the total power flowing drops off, and your voltage drops off as well. But you still get a pretty decent arc! But when you short circuit a battery (especially a lithium battery) your total power flow GOES UP!! And the voltage drops only minimally! I do realize that once you pull an arc from a breaker or other contact opening, the voltage rises up again. But PV is waaayyyy less potent in a short circuit condition than a battery!!
Another thing that factors into the whole debate around DC vs AC being "worse" at a given voltage is the fact that DC is a continuous current, where AC is not. AC is hitting zero amps 60 times each second (or 50 times, depending on where you live). That zero point every 17ms gives much more chance for an arc to get extinguished!
Anyone every done a short circuit test on solar panels at >100Vdc? That's a pretty serious arc! I did it just recently with ~120Vdc and ~20A short circuit current! Anyone care to try a short circuit test on a battery that is >100Vdc? If someone is brave enough to do this, please video it and show us the results!
By the way, here is a YouTube video by StyroPyro that shows some pretty serious DC arcing!
I don't think he runs very high voltage in that video unfortunately.... I couldn't remember from when I had watched it before, but just skimming through looks like maybe ~60-72Vdc or so. (5S or 6S at 12V??) (Though I don't think much higher voltage would be very safe, to be honest.)
So anyway.... Are any of you guys that are saying high voltage batteries aren't inherently more dangerous than high voltage PV up for the challenge??
dougbert
Solar Addict
been around for a couple of years now
Tesla Model 3 Standard Range Battery Pack and Controller
Salvaged Tesla Model 3 Standard Range Battery Pack - Nominally 48-50kWh and nominally 355 volts. Includes EVTV pack controller and display to allow you to turn on the Model 3 battery pack, perform precharge and control access to the battery. Indicates voltage, current, power, SOC, and much more...
store.evtv.me
Tesla Model 3 Long Range Battery Pack and Controller
Salvaged Tesla Model 3 Long Range Battery Pack - Nominally 73 to 75kWh and nominally 355 volts. Includes EVTV pack controller and display to allow you to turn on the Model 3 battery pack, perform precharge and control access to the battery. Indicates voltage, current, power, SOC, and much more...
store.evtv.me
Sandi 30kw 300-400vdc Input
This is a SANDI 30 kiloWatt DC to AC inverter. Perfect for the 300-400vdc input range of our Model 3 battery. This version includes dry contacts for a frequency shift from 60.00 to 62.5 Hz, allowing our Model 3 Controller to shut down microgrid-tied inverters such as the Enphase IQ series or the...
store.evtv.me
$30,000 plus (LOL) shipping. they actually have shipped many
charge controller
Charging 300-350VDC battery?
I’m trying to help out my brother who is interested to capture solar energy into a 350VDC battery to power his well pump overnight. He’s found several OTS batteries in the 300-350VDC range but is striking out on finding any solar charge controllers that charge within that voltage range. I’ve...
diysolarforum.com
Last edited:
MajicDiver
Solar Enthusiast
Of course it’s important to realize that “HV batteries “ mean different things to different people. There are a number of different varieties to consider, I’ll describe two, I’d be interested if others can describe other design styles:
1). A high voltage battery constructed using a string of cells in series (or series parallel) such that the assembly has a high output voltage.
2). A “group” of one or more low voltage batteries arranged in series or series parallel but uses a dc-to-dc converter to boost the voltage to high voltage before leaving the battery “enclosure”.
Suijkerbuijk
I cannot be held responsible for this information.
High Voltage 350v 400v 436v 700v Solar Charger Controller Pwm 100a Cp Wall-mounted Solar Charge Controller For Solar - Buy Pwm 50a/75a/100a Controller,Pwm Solar Charge Controller,Manual Pwm Solar Charge Controller Product on Alibaba.com
High Voltage 350v 400v 436v 700v Solar Charger Controller Pwm 100a Cp Wall-mounted Solar Charge Controller For Solar - Buy Pwm 50a/75a/100a Controller,Pwm Solar Charge Controller,Manual Pwm Solar Charge Controller Product on Alibaba.com
Wel here is a solar chargers go from
High Voltage 350V 400V 436V 700V Solar Charger Controller Pwm 100a Cp Wall-mounted Solar Charge Controller .
50A 100A MPPT Solar Charge Controller 220V 300V 350V Solar Controller Manufacturer,Supplier,Exporter
50A 100A MPPT Solar Charge Controller 220V 300V 350V Solar Controller available at the Affordable price in Christchurch, New Zealand. DANICK POWER LTD as a Manufacturer, Supplier and Exporter of 50A 100A MPPT Solar Charge Controller 220V 300V 350V Solar Controller in Christchurch, New Zealand...
www.danickpower.com
And here mppt model
All the batteries in that video are parallel...Have any of you considered the DC arc on HV DC batteries, and what it takes to extinguish that arc??
PV has a very limited available fault current as compared to batteries! Especially Lithium batteries! The reason that they can be charged at way higher rates than lead acid batteries is the same reason that they can also produce way higher output currents than lead acid batteries! (When compared AH/AH)
Plus PV is generally not stringed at more than 2P. Usually the second string in parallel brings the available fault current up to the short circuit current rating. So you really shouldn't have more than 2 strings in parallel.
Example:
(12) HT 450w Bi-facial solar panels, stringed 6S2P, would give you 246.6Vmpp and a SCC of around 22Adc (plus a few amps from backside, if you wish). Total wattage rating of 5,400w. (Again, plus a little bit from backside, if you wish.)
A 5kWh battery at "48V" nominal (51.2V actual) could easily do a discharge of 100Adc (I'm referring to what the cells could handle, at least for short periods.) Short circuit current would be magnitudes higher!
A 5kWh battery at 400Vdc would be 12.5AH. Therefore going off of the same 1C discharge that I used for the 48V battery, this theoretical battery could easily push 12.5A for quite a while. HOWEVER, if you were to short circuit this 400V battery, you would get MUCH HIGHER amperage!! Plus, the voltage wouldn't dop to zero like it does with a PV short circuit!
What if we were talking about 30-60kWh of high voltage DC battery? Because really, that is where the high voltage battery argument shines, right? We would be talking 75-150AH.... Anybody wanna mess with 500-1,000Amps of fault current at 400Vdc??
My biggest point here is that when you have a short circuit on PV, the total power flowing drops off, and your voltage drops off as well. But you still get a pretty decent arc! But when you short circuit a battery (especially a lithium battery) your total power flow GOES UP!! And the voltage drops only minimally! I do realize that once you pull an arc from a breaker or other contact opening, the voltage rises up again. But PV is waaayyyy less potent in a short circuit condition than a battery!!
Another thing that factors into the whole debate around DC vs AC being "worse" at a given voltage is the fact that DC is a continuous current, where AC is not. AC is hitting zero amps 60 times each second (or 50 times, depending on where you live). That zero point every 17ms gives much more chance for an arc to get extinguished!
Anyone every done a short circuit test on solar panels at >100Vdc? That's a pretty serious arc! I did it just recently with ~120Vdc and ~20A short circuit current! Anyone care to try a short circuit test on a battery that is >100Vdc? If someone is brave enough to do this, please video it and show us the results!
By the way, here is a YouTube video by StyroPyro that shows some pretty serious DC arcing!
I don't think he runs very high voltage in that video unfortunately.... I couldn't remember from when I had watched it before, but just skimming through looks like maybe ~60-72Vdc or so. (5S or 6S at 12V??) (Though I don't think much higher voltage would be very safe, to be honest.)
So anyway.... Are any of you guys that are saying high voltage batteries aren't inherently more dangerous than high voltage PV up for the challenge??
12V... MASSIVE current potential.
DPC
Solar Enthusiast
I just posted a video of the Kiruna K1050E
It had two stacks of NiCad batteries in it and I got a hell of a lot of shocks.\
I believe it was 220 volts..
It had two stacks of NiCad batteries in it and I got a hell of a lot of shocks.\
I believe it was 220 volts..
Robbert
Solar Enthusiast
Everyone makes mistakes once in a while; at least I do.
Got hit by 220v numerous times and did not like it
with DIY batteries we pretty often are doing stuff inside the battery (or battery shelf) and I personally don't like the idea to work on something lethal like a HV battery.
If it's not DIY, and a matter of stacking stuff and plugging pre-made plugs in, than i would do it. In my DIY system, I indeed am afraid of HV.
Got hit by 220v numerous times and did not like it
with DIY batteries we pretty often are doing stuff inside the battery (or battery shelf) and I personally don't like the idea to work on something lethal like a HV battery.
If it's not DIY, and a matter of stacking stuff and plugging pre-made plugs in, than i would do it. In my DIY system, I indeed am afraid of HV.
jpwhit
New Member
I've used fair number of SMA inverters in the past. And I started out using Sunny Boy Storage inverters for my latest installs with HV Batteries. The kind of shenanigans you're describing with their firmware updates, and the things they do to "protect" their interfaces, caused me to ditch them and move to GoodWe inverters.
Some of the problems with Sunny Boy Storage IMO, is it was pretty much a dead product by the time it came out. Seems like they had already decided to revamp the product line with the new all-in-one Sunny Boy Smart Energy products.
The Sunny Boy Smart Energy products actually look fairly interesting as an all-in-one HV DC Hybrid Inverter, and the prices for the models they have out seems fairly good with most of the one out being less than $2k. But I wouldn't be willing to jump back on their stuff if they don't shape up their act with firmware and supporting different battery protocols more openly.
jpwhit
New Member
I've used plenty of MOSFETs in designs with ratings much higher than 60V. That actually was true when MOSFET became pretty commonly available many years ago. But I was curious how high of voltage ratings were available now, so did a quick search on Digikey.com for MOSFETs rated above 1000 VDC. They have 572 to chose from with a status of "in stock". They go up to 4500V rating. That's actually quite a bit higher than I was expecting.
jpwhit
New Member
Have any of you considered the DC arc on HV DC batteries, and what it takes to extinguish that arc??
PV has a very limited available fault current as compared to batteries! Especially Lithium batteries! The reason that they can be charged at way higher rates than lead acid batteries is the same reason that they can also produce way higher output currents than lead acid batteries! (When compared AH/AH)
Plus PV is generally not stringed at more than 2P. Usually the second string in parallel brings the available fault current up to the short circuit current rating. So you really shouldn't have more than 2 strings in parallel.
Example:
(12) HT 450w Bi-facial solar panels, stringed 6S2P, would give you 246.6Vmpp and a SCC of around 22Adc (plus a few amps from backside, if you wish). Total wattage rating of 5,400w. (Again, plus a little bit from backside, if you wish.)
A 5kWh battery at "48V" nominal (51.2V actual) could easily do a discharge of 100Adc (I'm referring to what the cells could handle, at least for short periods.) Short circuit current would be magnitudes higher!
A 5kWh battery at 400Vdc would be 12.5AH. Therefore going off of the same 1C discharge that I used for the 48V battery, this theoretical battery could easily push 12.5A for quite a while. HOWEVER, if you were to short circuit this 400V battery, you would get MUCH HIGHER amperage!! Plus, the voltage wouldn't dop to zero like it does with a PV short circuit!
What if we were talking about 30-60kWh of high voltage DC battery? Because really, that is where the high voltage battery argument shines, right? We would be talking 75-150AH.... Anybody wanna mess with 500-1,000Amps of fault current at 400Vdc??
My biggest point here is that when you have a short circuit on PV, the total power flowing drops off, and your voltage drops off as well. But you still get a pretty decent arc! But when you short circuit a battery (especially a lithium battery) your total power flow GOES UP!! And the voltage drops only minimally! I do realize that once you pull an arc from a breaker or other contact opening, the voltage rises up again. But PV is waaayyyy less potent in a short circuit condition than a battery!!
Another thing that factors into the whole debate around DC vs AC being "worse" at a given voltage is the fact that DC is a continuous current, where AC is not. AC is hitting zero amps 60 times each second (or 50 times, depending on where you live). That zero point every 17ms gives much more chance for an arc to get extinguished!
Anyone every done a short circuit test on solar panels at >100Vdc? That's a pretty serious arc! I did it just recently with ~120Vdc and ~20A short circuit current! Anyone care to try a short circuit test on a battery that is >100Vdc? If someone is brave enough to do this, please video it and show us the results!
By the way, here is a YouTube video by StyroPyro that shows some pretty serious DC arcing!
I don't think he runs very high voltage in that video unfortunately.... I couldn't remember from when I had watched it before, but just skimming through looks like maybe ~60-72Vdc or so. (5S or 6S at 12V??) (Though I don't think much higher voltage would be very safe, to be honest.)
So anyway.... Are any of you guys that are saying high voltage batteries aren't inherently more dangerous than high voltage PV up for the challenge??
Hmmm, you post of video of a low voltage battery system with massive cables, just like folks are doing with LV battery systems, as an argument against HV battery systems
.Even if you didn't install a 25 or 30 amp fuse near the batteries, which you should because that's more than the current you'll ever need, the 10 gauge wires used to connect a HV battery to the inverter would burn up and act like a fuse and instantly open up. The battery system in that video is capable of more than tens of thousands of amps. No HV battery is capable of anywhere close to those kinds of currents.
I made this exact point earlier in the thread, HV battery systems just aren't capable of carrying the kinds of currents that LV battery systems can. So, for a lot of scenarios, there is less risk of accidents having to do with high currents. 10 Ga wire can only carry about 50 amps and that kind of current range is possible in a PV or a Battery system. So really not much practical difference.
DIYrich
Solar Wizard
All else being equal, I'm happy to work with HV. With HV AC, I can turn off the circuit, and work safely.
With diy batteries, it gets to a point where you are working with live wires. Can't turn it off when connecting all the cells together. 500v is different from 50v.
zanydroid
Solar Wizard
There is more expertise out there that you can avail of on 240VAC, from all the electrical DIY and electrician forums. I'm pretty sure with 3 months of forum reading, I can get farther with self education on 240VAC, than 240VDC battery systems.
I am less afraid of 600VDC solar strings than 600VDC battery systems because there's existence proof that people aren't killing themselves left and right with their solar strings, despite minimal safety education. There aren't enough datapoints for battery systems and I don't want to be an early adopter.
For VDC, I don't know yet where to get the training on that -- do I have to be a EV tech or something? What's the flashover risk and do I need special PPE? What safeties are taken care of by the traction battery BMS / module BMS, and which ones do I still need to know about? Maybe I just need to go on the right forums to get the appropriate certifications.
IMO the early adoption drivers are
- Availability of cheap equipment
- Accessibility of building hardware from scratch (I don't think very many people in the world are going to be able to build high voltage DC circuits from scratch)
- Education on safe practices (and this is hampered because unlike 240VAC you don't have a 120 year old profession of being an electrician that has built up a corpus of learning material. It'll take a long time for this to bootstrap on YouTube and forums)
- Intro classes in university and community college do not work at these DC voltage levels. So you don't have EZ mode onboarding. While trade school has plenty of people working at 240VAC right away.
- I bet the natural inclination of a lot of trade school and university educators would be, "No thank you", if posed the question of how to bootstrap this expertise in DIY community. So it'll be up to some adventurous individual innovators.
jpwhit
New Member
I find both of these post interesting and insightful. Because they both bring up valid concerns relative to what's safe and not safe to do, but probably more importantly where do you find the right source of information on the subject. I'll try to find some time in the next few days to write up and post some of what I've learned and/or know on the topic. Not claiming it'll be all-inclusive, but it's a start. And like anything you read on the internet, it's always good to validate from multiple sources.....
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 21,483
Like SBS, SBSE will require ABU or similar (transfer switch and auto-transformer) for grid-backup split phase.
If the pair is comparable to an AIO, this is a benefit because you can buy without if not needed, also I think the ABU could be put elsewhere, e.g. near service entrance, while inverter is remote at panels (with battery.)
SBSE has wimpy surge, about 120% of rated power. Some competing AIO may do better.
Since I picked up SBS and LG RESU-10H (sale of dumped material, therefore cost effective), I plan to use that for peak shaving and shoving into the grid during super-peak, when I get moved to Solar Billing Plan (NEM 3.0) early next year.
Paired with RESU-10H, which has bidirectional boost converter from 150V native battery, SBS reportedly has a hiccup and drops AC coupled PV inverters, so can't really function forever as backup. That should not be a problem for a hybrid like StorEdge or SBSE. Maybe the newer LG RESU-xx Prime will be supported on SBSE.
The thumbnail is clearly 5S. Which would put it at (5x12V) 60 volts.
First of all, this video looks to be ~60V, not 12, 24 or 48V. (See my marked up screenshot of his thumbnail above.) And second, I was not using that video "as an argument against HV battery systems". I had just used that to illustrate arc capability of batteries in general.Hmmm, you post of video of a low voltage battery system with massive cables, just like folks are doing with LV battery systems, as an argument against HV battery systems
Any fuse on a HV battery needs to be rated to withstand the arc from the high voltage while opening up under fault current. The higher the voltage, the further the arc will reach!
As far as 10 gauge wire goes, you are looking at ~30A rated current. 30A x 400Vdc = 12,000 watts. At 12,000 watts you have tons of readily available 48V inverters.
I would think at 20,000 watts or more is where a HV battery would really fit in... at that point you need (20,000 watts/400Vdc) 50A of current. That means 8 gauge wire, which is rated ~55A. I would assume on a short run from HV battery to HV inverter that 8 gauge would easily carry hundreds of amps if not thousands! My assumption is partially based off of a test that we did with shorting out 22 gauge wire on a 6V golf cart battery. We connected ~8 feet of thermostat wire to the battery, then put a wirenut on the end. The coating melted off very quickly! I believe we saw ~140A IIRC.
That is not a true comment.... A quick Google search tells me that the Tesla Model S's motors take up to a combined total of 615kW (for 825 bhp) and the battery is 375Vdc. That comes out to (615,000 watts/375Vdc) 1,640 amps!! And that is not short circuit current!
HV will arc waayyy sooner than LV! That in itself deems it more dangerous!
Where are you getting your 50 amps number??? #10 copper is definitely not NEC rated to 50 amps....... And if you are saying it won't carry more than 50 amps because of resistance, etc., then I challenge you to try doing a dead short on even a 6V battery using #10 and put a clamp meter on there! You will have much much more than 50A!
Other than the extinguishing the arc in high voltage DC, I am not more afraid of high voltage DC than I am of low voltage DC and I am sure that this arcing problem can be solved.
As for my own situation, I currently use about 10kWh per day and if it makes sense economically, I would certainly ditch the inverter and use high voltage DC for things like induction cooking and air-conditioning, but use low voltage DC for things that don't use much energy like lights, tv etc. Maybe even use two batteries, one for the high voltage stuff and one for the low voltage stuff.
The problem for me is a lack of knowledge with high voltage DC or that there is equipment that runs on high voltage DC and will be available at a reasonable price. Looking forward to learn more, not just the technical side, but also economics.
As for my own situation, I currently use about 10kWh per day and if it makes sense economically, I would certainly ditch the inverter and use high voltage DC for things like induction cooking and air-conditioning, but use low voltage DC for things that don't use much energy like lights, tv etc. Maybe even use two batteries, one for the high voltage stuff and one for the low voltage stuff.
The problem for me is a lack of knowledge with high voltage DC or that there is equipment that runs on high voltage DC and will be available at a reasonable price. Looking forward to learn more, not just the technical side, but also economics.
Nope. Good (silicon) ones go to 200V, and you can get them rated to 600V. In fact the most popular MOSFET out there for high power ebikes is the IRFB4110, a 100V/180A MOSFET (so good up to about 72V battery.)
Above about 200V, the switch of choice used to be IGBTs since they have somehwat lower losses (for the same price) than MOSFETs. Silicon carbide changed all that. Now 600V is no problem for SiC MOSFETs, and many inverters use them.
More than that. The plaid can put out 760kw, and the battery is going to be sagging to ~350 volts at those loads. So that's over 2000 amps.
EV batteries have far more (power) performance than any designer of residential systems is ever going to need.
Ampster
Renewable Energy Hobbyist
My first experience with Lithium batteries was an EV conversion using 36 LFP cells and If I could have found an inverter to run at over 100 volts I would have gone that route. I am sure there were inverters but not with the features I was looking for.
Ampster
Renewable Energy Hobbyist
I agree that availability of inverters is the main reason. There are some high voltage BMSs but their heritage is EVs and the have a lot of features not needed for stationary storage so their prices tend to be high. A high voltage DIY battery can be assembled from a string of LFP cells and the cost per kWh should not be higher than the typical DIY battery.
Similar threads
