Is the math correct for newbies? 48v x 4 = 240v LiPo Batteries.

[AbdulSubhan]

Hey guys I'm new to this stuff, just saw a couple of high voltage inverters from good and huwae some Chinese companies, IF we connect our batteries in series to the point of raising the volt to upper limit of 48volts to say 150 or 240, the inverter with the specification of those volt will support the batteries it will charge and discharge efficiently or there's a good chance it won't allow it.

Also what will happen to the batteries and how different the fuse and breaker have to change? Mr.prowse using fast acting T fuse. If we have a server rack of high voltage what's needed to be added for safety.

 

[Bud Martin]

Hey guys I'm new to this stuff, just saw a couple of high voltage inverters from good and huwae some Chinese companies, IF we connect our batteries in series to the point of raising the volt to upper limit of 48volts to say 150 or 240, the inverter with the specification of those volt will support the batteries it will charge and discharge efficiently or there's a good chance it won't allow it.

Also what will happen to the batteries and how different the fuse and breaker have to change? Mr.prowse using fast acting T fuse. If we have a server rack of high voltage what's needed to be added for safety.

Are you saying that you have inverter that is designed to run on 48Vdc but you want to supply it to 150 or 240Vdc instead and you want to know if that will work or not, correct?

 

[AbdulSubhan]

Are you saying that you have inverter that is designed to run on 48Vdc but you want to supply it to 150 or 240Vdc instead and you want to know if that will work or not, correct?

No, not talking about 48 volts inverters, look up high voltage inverters. they have high voltage range in 100-300 v

 

[Ohms_Cousin]

Some even go up to 600/700 VDC. Very efficient for running large loads but the cost of DC fuses/switches etc will be very high for these voltages and 600vdc is kind of scary. Still, the solar arrays are running at these voltages these days and plenty of DIY'ers do thier own solar installs.

 

[pollenface]

Some go up to 900vdc.

I think you'd have to put gloves on at some point.

 

[Supervstech]

No, not talking about 48 volts inverters, look up high voltage inverters. they have high voltage range in 100-300 v

Not easy… and 48V batteries have BMS units that can’t handle higher voltage, so you would need a complicated BMS… like from an ev battery, or similar.
Why are you considering this?

 

[Ohms_Cousin]

I am also in this boat - high voltage battery pack is used by the inverter I would like to use. 600/700 volts is nice for a series pack - 188 3.2v LiFePo4 batteries in series. That cuts down on a lot of complication and connections and things to go wrong. But 600/700v connections concern me with that many amps behind it. ATESS have some nice inverters and a local installer has done several installs of some bigger units and so far all good with them. However this pretty much means using the ATESS BMS. But that keeps things simple as well.

 

[Bvillebob]

I've spent a lot of time working with high voltage DC, up to 6KV, and I'd never, ever want to have 600v or more with the capacity to deliver 1000's of amps behind it in my house, just too damn scary. I got bit by HV DC once, woke up across the room with the smell of
bbq in the air and a big hole blown out of my forearm. Fortunately an old timer had beat into my head that you only ever use one hand a time and rest your arm on the chassis, so the voltage went from hand to forearm, not through my heart or I wouldn't be here.

HV is dangerous, heck, I stick with 24v because I'm a wimp.

 

[Ohms_Cousin]

Totally

I've spent a lot of time working with high voltage DC, up to 6KV, and I'd never, ever want to have 600v or more with the capacity to deliver 1000's of amps behind it in my house, just too damn scary. I got bit by HV DC once, woke up across the room with the smell of
bbq in the air and a big hole blown out of my forearm. Fortunately an old timer had beat into my head that you only ever use one hand a time and rest your arm on the chassis, so the voltage went from hand to forearm, not through my heart or I wouldn't be here.

HV is dangerous, heck, I stick with 24v because I'm a wimp.

Totally agree with this. However if one wants to use the ATESS inverters shown in the pdf uploaded that shows the range then what is one to do?

There are pro's and con's;

Pro's -

1/ HV dc is a way to keep amps down overall.
2/ HV dc is a way to reduce parallel strings in a given setup
3/ HV dc is a way to reduce number of connections each with thier own resultant resistance issues (it adds up overall)
4/ HV dc keep cables diameters more reasonable
5/HV dc is much better for high amp draws off the system overall. Suits really big battery systems.
6/ probably others as well that I am not thinking of right now.

I like the ATESS inverters but there are number of reasons I am hesitant to go that way (as per list). I feel comfortable with Victron but thats 48v and I need a really big battery for my needs. 48v packs in a 16s design means many 16s packs and one has to manage all that. Many 16s packs also gets very complicated. No easy path here.

Con's

1/ HV dc is just that HIGH VOLTAGE DC ! no second chances here if you mess up.
2/ HV dc will require some fairly hefty switch gear that can handle that HV arc
3/ HV dc is really not suitable for a DIY'er
4/ HV dc forces one into a proprietary system - most likely
5/ HV dc is not going to be something most people in these types of forums mess with much or know too much about. Hence no help on issues or problems from within the community.
6/ probably others as well that I am not thinking of right now.

 

[AbdulSubhan]

Not easy… and 48V batteries have BMS units that can’t handle higher voltage, so you would need a complicated BMS… like from an ev battery, or similar.
Why are you considering this?

Yup that's exactly what I thought it's the BMS would be limited factor for already assembled batteries.
I'm not planning to doing it but saw sm HV inverter so I was curious, lol