MPP LV6548

[Sanwizard]

I just received my LV2724 for a work shed, and a 6548 for the house. To me its all about simplicity and value. I also just ordered 16 280ah cella for the 48V source. Anyone know of the best BMS for those Lishen cells?

 

[jasonhc73]

I just received my LV2724 for a work shed, and a 6548 for the house. To me its all about simplicity and value. I also just ordered 16 280ah cella for the 48V source. Anyone know of the best BMS for those Lishen cel

Where are you keeping the cells?

I don't use a bms. I use an active balancer.
I keep the batteries inside the house. I control the top and bottom with the LV6548 charge settings.
Bulk 58.4V (3.65 per cell)
Float 53.1V (3.319V per cell ~ 80% SOC
Bottom cutoff is set to 44V ( 2.75V per cell, ~ 5% SOC)

My brand new cells rest at just 3.326V (53.216 V, ~82% SOC). Trying to force them to 3.65 is a colossal waste of energy and time. The time it takes to get them from 99.5% to 100% is pretty much the same amount of time it takes to charge them from 10% to 85%. And then even if you manage to get them to 3.65V, they just return to about 3.3V anyway.

This is 10 days just sitting after being charged to 3.65V which took 4 days from 3.297V.

 

[DanF]

Where are you keeping the cells?

I don't use a bms. I use an active balancer.
I keep the batteries inside the house. I control the top and bottom with the LV6548 charge settings.
Bulk 58.4V (3.65 per cell)
Float 53.1V (3.319V per cell ~ 80% SOC
Bottom cutoff is set to 44V ( 2.75V per cell, ~ 5% SOC)

My brand new cells rest at just 3.326V (53.216 V, ~82% SOC). Trying to force them to 3.65 is a colossal waste of energy and time. The time it takes to get them from 99.5% to 100% is pretty much the same amount of time it takes to charge them from 10% to 85%. And then even if you manage to get them to 3.65V, they just return to about 3.3V anyway.

This is 10 days just sitting after being charged to 3.65V which took 4 days from 3.297V.
View attachment 35720

The more I have researched the BMS stuff, the more I feel like this is exactly the way I want to go as well for my system as well. One thing I'm still thinking about is possibly adding a Victron Smart shunt and would like to have a screen possibly mounted on the door of my battery compartment. I could also check it with the phone too.
Still raking over some idea's on the DC side, but agree with the fact that I can let the LV6548's manage the high and low on the batteries while the active balancer takes care of the rest.
She's coming along. Batteries probably won't be here until early March though.

 

[jasonhc73]

The more I have researched the BMS stuff, the more I feel like this is exactly the way I want to go as well for my system as well. One thing I'm still thinking about is possibly adding a Victron Smart shunt and would like to have a screen possibly mounted on the door of my battery compartment. I could also check it with the phone too.
Still raking over some idea's on the DC side, but agree with the fact that I can let the LV6548's manage the high and low on the batteries while the active balancer takes care of the rest.
She's coming along. Batteries probably won't be here until early March though.

That is a beautiful setup.

Paint that white space with some chalkboard paint, so some chaos can be drawn.

 

[DanF]

Great Idea! hahaha

 

[Sanwizard]

I saw this on their site and wondering if anyone's actually seen one or had any experiences with it. The manual is dated 10/20/2020 so appears pretty new.

Brochure & Manual

Quick question. With 3.6v 280ah cells, 14 x 3.6 = 50V. The LV6548 requires 48 volts. That being the case, why are folks creating 16s strings? 3.6x16 = 57V

The question is which is better or required to power the inverter? 50 or 57 volts?

 

[jasonhc73]

Quick question. With 3.6v 280ah cells, 14 x 3.6 = 50V. The LV6548 requires 48 volts. That being the case, why are folks creating 16s strings? 3.6x16 = 57V

The question is which is better or required to power the inverter? 50 or 57 volts?

280ah cells are nominal 3.2V, don't use the 100% SOC number.

The inverter works on a range of voltage. Better doesn't mean anything when you are doing incorrectly. "12V batteries" usually work best at 13.6, and get charged with 14.4, and often work fine down to 9.6V.

Keep it simple and use LiFePO4 in 16S. Other lithium chemistries work in 15S. They are not the same discharge curve or have the same nominal voltage.

 

[Will Prowse]

I will have my LV6548 in a week. Going to stick it in an enclosed trailer and charge my tesla with it. Such a great price considering the output and features.

 

[jasonhc73]

I will have my LV6548 in a week. Going to stick it in an enclosed trailer and charge my tesla with it. Such a great price considering the output and features.

I hope you got two. It is only 120V single phase as a single.

 

[Dave (Boog)]

Quick question. With 3.6v 280ah cells, 14 x 3.6 = 50V. The LV6548 requires 48 volts. That being the case, why are folks creating 16s strings? 3.6x16 = 57V

The question is which is better or required to power the inverter? 50 or 57 volts?

Lishen Lifepo4 cells are 3.2 nominal not 3.6v. 16s is correct for 48v using Lifepo4.

 

[Maestro]

I'm new to the solar game and still trying to wrap my head around it. So two simple and perhaps stupid questions.
Can you tie 16ea 300w solar panels to a single LV6548?
Does the LV6548 charge batteries simultaneously with output flowing?

 

[jasonhc73]

I'm new to the solar game and still trying to wrap my head around it. So two simple and perhaps stupid questions.
Can you tie 16ea 300w solar panels to a single LV6548?
Does the LV6548 charge batteries simultaneously with output flowing?

16 times 300 equals 4800.
So, yes you can put them on one LV6548, PROBABLY. Put 2500 w of each panel on each of the PV inputs and it will probably work great. Most likely 4 strings of 5, 2 in parallel is the simplest way to draw it up and think about it.

The back of the panel has a label. Take a picture and post it.

Yes the charger and inverter work simultaneously.

 

[Sanwizard]

16 times 300 equals 4800.
So, yes you can put them on one LV6548, PROBABLY. Put 2500 w of each panel on each of the PV inputs and it will probably work great. Most likely 4 strings of 5, 2 in parallel is the simplest way to draw it up and think about it.

The back of the panel has a label. Take a picture and post it.

Yes the charger and inverter work simultaneously.

I plan on using 16 x 330w 40v 9.5A as 4 serial and 2 parallel two each input. Thats 160V at 19A per input. They are Qcell Gen5 panels. I checked with Watts247, and they said that should work. The limits are 250v and 18A per input, but it seems the amps are a bit flexible.

 

[jasonhc73]

I plan on using 16 x 330w 40v 9.5A as 4 serial and 2 parallel two each input. Thats 160V at 19A per input. They are Qcell Gen5 panels. I checked with Watts247, and they said that should work. The limits are 250v and 18A per input, but it seems the amps are a bit flexible.

The amps are "variable" because that is literally what any MPPT does. The MPPT pulls as much current from the panels as the panels have. It is not that the MPPT take what the panels give.

The higher the voltage any sting you can assemble the better. More voltage means less amps for the same Watts.

 

[Sanwizard]

The amps are "variable" because that is literally what any MPPT does. The MPPT pulls as much current from the panels as the panels have. It is not that the MPPT take what the panels give.

The higher the voltage any sting you can assemble the better. More voltage means less amps for the same Watts.

Ok, now you have me thinking of redoing the panel connections, as I can put two more panels in each string easy.

 

[Sanwizard]

The amps are "variable" because that is literally what any MPPT does. The MPPT pulls as much current from the panels as the panels have. It is not that the MPPT take what the panels give.

The higher the voltage any sting you can assemble the better. More voltage means less amps for the same Watts.

Do both PV inputs have to be the same on the LV6548? Is it ok to have an unbalanced set?

 

[Sanwizard]

I'm up and running.

I used 6awg for the AC, they went in very easy.

View attachment 32521

Did you have to pre-charge the inverter capacitors before hooking up the batteries? If not, if you plug it into AC first before batteries, wouldnt that also charge things up?

 

[jasonhc73]

Did you have to pre-charge the inverter capacitors before hooking up the batteries? If not, if you plug it into AC first before batteries, wouldnt that also charge things up?

It does not precharge from the A/C.

Get a switch and a circuit breaker before you connect the battery.

Otherwise, it will arc. And not just a little arc, but about a 200 amp welding type arc.




HD Switch:

https://www.amazon.com/Blue-Sea-Systems-Circuit-Battery/dp/B000K2K800/ref=pd_rhf_ee_s_rp_c_2_0_12?_encoding=UTF8&pd_rd_i=B000K2K800&pd_rd_r=d8e80262-1e87-4d37-8880-22791927c2e1&pd_rd_w=usHlL&pd_rd_wg=6xeBO&pf_rd_p=45ea3989-28e2-45c9-97ac-7e99f613a91b&pf_rd_r=K09BJWZHVD0JXVFCP1HX&psc=1&refRID=K09BJWZHVD0JXVFCP1HX

HD Distribution block

Amazon.com: Bay Marine BusBar - Dual Large 4-Post Power Distribution Block - 3/8" & 3/8": Electronics

Buy Bay Marine BusBar - Dual Large 4-Post Power Distribution Block - 3/8" & 3/8": Connecting Blocks - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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DC Circuit Breakers

30A-300A AMP Circuit Breaker Fuse Manual Switch 12-48V DC Car Boat Waterproof US | eBay

30A-300A AMP Circuit Breaker Fuse 12-48V DC Car Boat Waterproof Manual Switch. High amp thermal trip circuit breakers with a manual reset switch suitable for use on auxiliary DC electrical systems. Manual Reset Switch.

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You can use a resistor to precharge if you want to skip the "safety" system. Or you can just jam the cables on the connector quickly. (it's a little scary but if you want it done now and can't wait)

 

[Sanwizard]

It does not precharge from the A/C.

Get a switch and a circuit breaker before you connect the battery.

Otherwise, it will arc. And not just a little arc, but about a 200 amp welding type arc.

View attachment 39904


HD Switch:

https://www.amazon.com/Blue-Sea-Systems-Circuit-Battery/dp/B000K2K800/ref=pd_rhf_ee_s_rp_c_2_0_12?_encoding=UTF8&pd_rd_i=B000K2K800&pd_rd_r=d8e80262-1e87-4d37-8880-22791927c2e1&pd_rd_w=usHlL&pd_rd_wg=6xeBO&pf_rd_p=45ea3989-28e2-45c9-97ac-7e99f613a91b&pf_rd_r=K09BJWZHVD0JXVFCP1HX&psc=1&refRID=K09BJWZHVD0JXVFCP1HX

HD Distribution block

Amazon.com: Bay Marine BusBar - Dual Large 4-Post Power Distribution Block - 3/8" & 3/8": Electronics

Buy Bay Marine BusBar - Dual Large 4-Post Power Distribution Block - 3/8" & 3/8": Connecting Blocks - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

DC Circuit Breakers

30A-300A AMP Circuit Breaker Fuse Manual Switch 12-48V DC Car Boat Waterproof US | eBay

30A-300A AMP Circuit Breaker Fuse 12-48V DC Car Boat Waterproof Manual Switch. High amp thermal trip circuit breakers with a manual reset switch suitable for use on auxiliary DC electrical systems. Manual Reset Switch.

www.ebay.com

You can use a resistor to precharge if you want to skip the "safety" system. Or you can just jam the cables on the connector quickly. (it's a little scary but if you want it done now and can't wait)

Thanks for the tip!

 

[DanF]

MPPSolar LV6548 Inverters in "Split Phase" 240v operation. Solar panel install to come. They sent the wrong ones! It's been a bad experience with my purchase. I'll elaborate on that when I can.
The start up, AC and DC side Video's HERE