60VDC Lifepo4 battery 20S 280AHr. I have two of these batteries, laser welded and already assembled in nice steel container with their BMS, Fan etc.

[Jose Arias]

Hello! This is my first post. I have two brand new in a box 60VDC Lifepo4 nominal batteries 20S 280AHr. They are very well build, with laser welded busbars and terminals, since they're already assembled in nice steel container with their BMS, Fan, ventilating channel, etc. I don't want to start cutting cells or modifying to make it 48VDC, instead I would like to buy an "All in One" that can work within these voltage range "62VDC-69VDC". The inverter I have now is 48Volts but it self protect at 60volts. Wonder if any of you guys encounter this problem before? or have a solution? Thanks!

 

[sunshine_eggo]

Good luck. It's going to be a hard find. I've never seen an AiO that goes above 60V. My Quattro cuts off at 66V.

 

[Jose Arias]

Good luck. It's going to be a hard find. I've never seen an AiO that goes above 60V. My Quattro cuts off at 66V.

Thanks sunshine! At least yours cut off at 66V. My Battery @ 100%SOC will be around 72V. I would like to use it Between 62-69V.

 

[sunshine_eggo]

Thanks sunshine! At least yours cut off at 66V. My Battery @ 100%SOC will be around 72V. I would like to use it Between 62-69V.

69 would be 3.45V/cell, so you could get it 98%+ charged if you have the time.

IMHO, you may have better luck piecemealing components:

This inverter would do it:

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Victron 48V 150Voc MPPT can be set for 69.56V peak charge voltage:



Many lower end MPPT have a custom setting that allows up to 17V for 12/24 models. if you find a 48V model that supports that range, that would be 68V or 3.4V/cell... still high 90% charging if you have the daylight.

 

[Jose Arias]

Thanks Sunshine! I was thinking the same. The only thing is that, because I would like to be able to run almost whole house, power is a big factor. Another thought I had is the following. I found online and is on sale now "it was $24K" a very robust inverter 10KW LF 60Hz Split phase that withstand 15KW surges, designed for military, aviation, marine aplications, etc with 105-150VDc input. So, if I series my batteries will be perfect. The only thing that make think twice is the price around $5K and that the efficiency is around 80%, Plus I'll need find a way to charge both batteries. What's your opinion going that route?

 

[sunshine_eggo]

Can you link it?

 

[Jose Arias]

Here are some screenshoots from the website that apply to the model I'm considering

 

[sunshine_eggo]

Something you need to verify is if the batteries can be placed in series for higher voltage. Their BMS must be designed to handle 2X the voltage of a single battery. Many aren't.

 

[Jose Arias]

Thanks for your input! BMSs are JBD-AP21S002 300Amp. Don't have the specs neither. I don't know if exist a 40S BMS. Could be possible charge the 120v serie bateery using two separate Victrons?

 

[sunshine_eggo]

Thanks for your input! BMSs are JBD-AP21S002 300Amp. Don't have the specs neither. I don't know if exist a 40S BMS.

A 40S BMS would be impractical if you want to keep the cases intact.

Could be possible charge the 120v serie bateery using two separate Victrons?

No.

I would continue to pursue a 60-72VDC inverter solution. You have some oddball batteries. IMHO, the goal should be to avoid additional oddballing.

 

[Jose Arias]

Well! You're right! I was thinking replacing the two 20S BMSs for one 40S if exist is something reversible and feasible for me.

 

[Jose Arias]

https://m.aliexpress.us/item/3256801320638462.html?gatewayAdapt=glo2usa4itemAdapt&_randl_shipto=US found this in china

 

[The Barn]

Hello! This is my first post. I have two brand new in a box 60VDC Lifepo4 nominal batteries 20S 280AHr. They are very well build, with laser welded busbars and terminals, since they're already assembled in nice steel container with their BMS, Fan, ventilating channel, etc. I don't want to start cutting cells or modifying to make it 48VDC, instead I would like to buy an "All in One" that can work within these voltage range "62VDC-69VDC". The inverter I have now is 48Volts but it self protect at 60volts. Wonder if any of you guys encounter this problem before? or have a solution? Thanks!

By a cheap all in one unit from Alibaba that has. Pwm charge controller and hook the battery up to the charge controller

 

[The Barn]

By a cheap all in one unit from Alibaba that has. Pwm charge controller and hook the battery up to the charge controller

Charge controller input

 

[sunshine_eggo]

By a cheap all in one unit from Alibaba that has. Pwm charge controller and hook the battery up to the charge controller

PWM operate by shorting the PV to the battery.

PWM can't regulate current.

This is not a viable solution AT ALL. Blown fuses of any size are a guarantee. Unfused - fire is the outcome.

 

[koppted]

The XW6848 will go up to 64V, and is a split phase machine. With 64v being you maximum charge you will still be able to use 18kwh out of the 20kwh total you have and increase the lifespan of your battery in the process.

 

[sunshine_eggo]

The XW6848 will go up to 64V, and is a split phase machine. With 64v being you maximum charge you will still be able to use 18kwh out of the 20kwh total you have and increase the lifespan of your battery in the process.

64V/20 = 3.2V/cell - maybe 20% SoC on a great day.

 

[koppted]

64V/20 = 3.2V/cell - maybe 20% SoC on a great day.

I clearly don't know what i'm talking about. I have a question regarding a similar battery that I have. Not in use yet. It is an 18s set of batteries with nominal voltage at 59.4v 260ah. Voltage range is 48.6 to 64.8.
My AIO will only go up to 62v how much capacity am i losing if I just use it as is?
Here is how i was doing my calculation I figured 64.8 x 260 = 16.8Kwh if I can charge to only 62 that would be 62 x 260 which would be 16.1kwh I thought that is not much of a loss but obviously this is the wrong way of looking at things. Do you mind explaining?

 

[sunshine_eggo]

Voltage vs. SoC vs. Wh is not linear. You can't multiply an arbitrary target voltage by Ah to get Wh.

The only valid way to compute Wh is using nominal voltage, which is 3.2V/cell.

18S * 3.2V * 260Ah = 14.976kWh - this is the calculated TOTAL rated kWh capacity of your battery. You can't get more out of it.

LFP has a nominal voltage of 3.2V.

Your 18S battery @ 59.4V nominal suggests 3.3V. Some references put LFP at 3.3V, but almost no battery manufacturers list it that way.

4S = 12.8V for 12V systems = 3.2V nominal per cell.
16S = 51.2V for 48V systems = 3.2V nominal per cell.

Going to assume your battery is actually 3.2V and 57.6V nominal.

You have to look at the charge voltage at peak. In the prior post, charging a LFP cell to 3.2V will barely put anything into it. Charging it to 3.30-3.35V will get somewhere around 30-40% into it.

62V / 18S = 3.444V/Cell. It is possible with a long absorption period to get LFP batteries to near 100% @ 3.45V/cell. I would expect if you had most of the day to "trickle" the battery at 3.444V/cell (62V), you could get to more than 95% SoC.

I would be concerned about any hazards associated with hitting the peak voltage of the unit on a daily basis.

Just throwing it out there in case you're made of money... Victron 48V inverters run to 66V, and their MPPT can run to 69.5V

 

[koppted]

Voltage vs. SoC vs. Wh is not linear. You can't multiply an arbitrary target voltage by Ah to get Wh.

The only valid way to compute Wh is using nominal voltage, which is 3.2V/cell.

18S * 3.2V * 260Ah = 14.976kWh - this is the calculated TOTAL rated kWh capacity of your battery. You can't get more out of it.

LFP has a nominal voltage of 3.2V.

Your 18S battery @ 59.4V nominal suggests 3.3V. Some references put LFP at 3.3V, but almost no battery manufacturers list it that way.

4S = 12.8V for 12V systems = 3.2V nominal per cell.
16S = 51.2V for 48V systems = 3.2V nominal per cell.

Going to assume your battery is actually 3.2V and 57.6V nominal.

You have to look at the charge voltage at peak. In the prior post, charging a LFP cell to 3.2V will barely put anything into it. Charging it to 3.30-3.35V will get somewhere around 30-40% into it.

62V / 18S = 3.444V/Cell. It is possible with a long absorption period to get LFP batteries to near 100% @ 3.45V/cell. I would expect if you had most of the day to "trickle" the battery at 3.444V/cell (62V), you could get to more than 95% SoC.

I would be concerned about any hazards associated with hitting the peak voltage of the unit on a daily basis.

Just throwing it out there in case you're made of money... Victron 48V inverters run to 66V, and their MPPT can run to 69.5V

Thanks, I appreciate it!