Are these good LiFePo4 batteries - Lossigy?

joepolcari

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Mar 5, 2021
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For testing see you tube - LiFePo batteries are practically indestructible.
 
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CJay

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Apr 27, 2021
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For testing see you tube - LiFePo batteries are practically indestructible.
Cool! (Pun intended)
But I was thinking more like a standard list of tests and procedures that people on this forum might work from... And maybe even to build up a reference database.
I've seen some of Will Prowse's testing on YouTube, but I'm not equipped for much of the testing he does.
 

Ken Wing

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Feb 15, 2021
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Will, it would be great if you could review these Lossigy 12v/300ah units, my friend who has an off grid house on the Mexican coast wants to buy 4 of them to use in a 12V or 24V storage application for his house. They are very well priced, but don't know how good they are.. thanks!!
 

Johnjayjrv

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Mar 31, 2021
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Watching this intensely as I am very interested in this battery. It'll fit perfect on the tongue of my trailer in a dual GC2 box. All other 200ah are too big.
 
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bderue

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Buy one. Take it apart and test the BMS similar to how Will does. If it fails or doesn't look like the ones Will prases in his videos; return it. Say it was damaged in the mail.
 

vermar70

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Hi,
I just re-tested my 300Ah Lossigy (yellow top) battery and got it to 298Ah before I shut the inverter off. I first tested it in Apr. and got 297Ah before it shut itself off at 10.25V. This time I intervened the test as my live voltage (under load) was at 10.0. After I removed the load (677W) the battery bounced up to 10.6V. It might have hit the actual 300Ah on the nameplate had I let it go. I didn't want to damage it. And hey - 298Ah - close enough. I've been using the battery in my RV for the past 4 months since that 1st test, but never dry camping. Also since that 1st test I have installed a Renogy 40A DC-DC charger that connects to my truck. It works very well so far. I am also in the process of installing a 700W solar charging (4-175W modules; 2S/2P) on the RV's roof. The solar power will go through a Victron 100/50 MPPT. Anyway........
Here are some notes that I took during the "draw down" test:
The space heater (load) was set to 2/3rds and drawing 1010-1020W from the battery from 100% down to 1%, then I lowered the load to 677W.
I watched the battery terminal temp climb to 111*F (getting warnings as it went over 108*) w/ outside ambient around 85*, but it went back down under 108* after lowering the load. Cables were warm, but not hot. Starting voltage was 12.76 @ 79A, then went to 12.55 @ 80.5A, and 12.01V @ 85A. The Ah used was 277Ah at 1% remaining charge, and 280Ah @ 0% remaining. The % remaining is just how I programmed the smart shunt. At 0% the battery still had 12.2V under load, so we continued on. At 12.0V the battery was at 284Ah. At 11.0V it was at 295. At 298Ah, the voltage was around 10.5V (maybe 10.6, but I'm guessing here cause I got scared and shut the test down :-O). The BMS did not shut this test down as it did in the first test in April.
 

vermar70

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Wait a minute; I just looked at my setup and I didn't shut the inverter down as I said above, but I opened the battery ground cutoff switch.
Now (2 hrs. later) when I connected the ground, the smart shunt says I have 11.4V. Time for more testing. It's dark and the RV motion sensor lights are on, this battery is continuing to rack up more Ahs. I turned the lights on inside the trailer (LEDs now flickering), and then ran the TV (has to go through the inverter), and also a fan. The voltage is now at 10.1 (don't know what the bms is doing) and the total draw is at 302Ah. So that's it for now. I shut the ground sw., and I'll get to charging back up tomorrow morning w/ half of the solar panels.
The Lossigy beat it's 300Ah claim, even if I had to creep up on it in the end.
I
 
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Spetz

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Hello All,

I just purchased the Lossigy 200Ah battery and here are some of my observations. There are (more than) a few things i don't quite understand about the behavior of their BMS

During the charge

The battery came in reading around 13.3V.
I connected to a DC power supply that is limited at 5A and was charging around ~14.5V...
The charge behavior was a bit strange. When monitoring the voltage visually ( i dont have a logger) i would see the battery slowly gain charge as expected. The strange part was that it was SUPER non-liner throughout.
  1. As example it would get to 13.5V and just sit there for several hours w/o moving, then in a matter of an hour it would trickle up to 13.6,13,7 then it would sit again for several hours. and the step pattern would repeat. All this time would be pegged at maximum current.
  2. The internal BMS cut-off at 14.2V which i thought was a little high.

During the discharge
I connected a resistive load to the battery through a Victron BMV-712. Also withouth a logger i was manually monitoring the voltage drop.
  1. I got to about 182Ah when the battery was at 12.6V
  2. at ~193Ah the battery was reading 11.76
  3. at 200Ah the batterywas reading around 10V or just under
  4. The battery finally cut-off at around 9.8V ( i double checked this wiht my volt meter)
The cutoff seems very low to me according to their post on amazon it should be 10.8.

Planning to recharge and do another test cycle

Quetions:
  1. Is there possible damage to the battery from going down so low?
  2. Is this typical behavior on the charge side?
  3. At the price i think at 190Ah+ this is a great buy i can make sure i dont over charge/discharge externally from their BMS but given the above is this thing going to last or am i just waiting on something else to go wrong here...

Sidebar: not a big fan of the Victron setup as it doesnt log unless i havent figure it out... it is super easy to reset the readings on accident in their app and as soon as you loose power you loose everything... Is there a better option that will actually log and has some onboard memory?


Appreciate the input.
 

Mia

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I’m still a newbie, but I thought LiFePO4 batteries could get discharged almost fully and was a big part of why people choose them? (That said, it may reduce the number of cycles available overall, especially if done on a regular basis.)
 

Gazoo

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I’m still a newbie, but I thought LiFePO4 batteries could get discharged almost fully and was a big part of why people choose them? (That said, it may reduce the number of cycles available overall, especially if done on a regular basis.)
For a 4S LiFePO4 battery, 10 volts is fully discharged and 14.6 volts is fully charged. Anything much above or below those voltages is asking for trouble.
 

Gazoo

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During the charge
I can't explain why the charge was not linear. But the BMS cutting off at 14.2 volts is a little low for a BMS HVD. Was that the voltage measured at the battery terminals? Does Lossigy claim the BMS balances the cells? This is from their sales page:

Charging
Charging voltage: 14.4-14.6V
Overvoltage disconnect voltage: 15V
Overvoltage reconnection voltage: 14.2V
Discharge
Low voltage disconnection voltage: 10.8V
Low voltage reconnection voltage: 10.6V
Undervoltage warning voltage: 12.4V

During the discharge
There was most likely not any damage to the cells. Does your volt meter measure to more decimal places? In other words did the LVD kick in at exactly 9.8 volts? And how accurate is your volt meter? Also there will be some voltage drop between the BMS's output and the voltage measured at the cells terminals. So the voltage measured at the cells terminals would be a bit higher than the voltage measured at the battery terminals.

It would help if they disclosed the BMS they are using although most manufacturers don't. It would be nice if the BMS had bluetooth.

Most if us keep the cells between the knees to increase cycle life and to keep the delta of the cells low. One should not rely on the BMS for LVD and HVD although it's good to test the BMS to make sure it's working properly as you did :) The BMS is supposed to be used as the last line of defense in case a device fails in the system.

The fact the battery tested at full capacity and the BMS is working is good. IMO you received a good battery at a good price. Sorry I can't halp with data logging.
 

Spetz

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Aug 26, 2021
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I can't explain why the charge was not linear. But the BMS cutting off at 14.2 volts is a little low for a BMS HVD. Was that the voltage measured at the battery terminals? Does Lossigy claim the BMS balances the cells? This is from their sales page:

Charging
Charging voltage: 14.4-14.6V
Overvoltage disconnect voltage: 15V
Overvoltage reconnection voltage: 14.2V
Discharge
Low voltage disconnection voltage: 10.8V
Low voltage reconnection voltage: 10.6V
Undervoltage warning voltage: 12.4V


There was most likely not any damage to the cells. Does your volt meter measure to more decimal places? In other words did the LVD kick in at exactly 9.8 volts? And how accurate is your volt meter? Also there will be some voltage drop between the BMS's output and the voltage measured at the cells terminals. So the voltage measured at the cells terminals would be a bit higher than the voltage measured at the battery terminals.

It would help if they disclosed the BMS they are using although most manufacturers don't. It would be nice if the BMS had bluetooth.

Most if us keep the cells between the knees to increase cycle life and to keep the delta of the cells low. One should not rely on the BMS for LVD and HVD although it's good to test the BMS to make sure it's working properly as you did :) The BMS is supposed to be used as the last line of defense in case a device fails in the system.

The fact the battery tested at full capacity and the BMS is working is good. IMO you received a good battery at a good price. Sorry I can't halp with data logging.
thanks,
agree that BMS should be used for safety not actual limits. I did want to test to ensure is working this was the main purpose of this test before i burry the battery in my setup...

I'm doing one more charge/discharge cycle to test consistency before i call this bttery OK and will then set appropriate cutoff limits with the controller on the charge/discharge side.

thanks for the input.
 

Mikem33

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Dec 4, 2021
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bought 2 lossigy 200ah 12 v batteries April 2021. Made a 12 v, 5.1 kWh battery bank with them for my Rv trailer, using a 200w renogy solar suitcase, Victron 100/30 mppt. They have worked great for me on many camping trips. Have not experienced any problem in charging by solar or AC both chargers Victron. All components fit in a tongue box from harbor freight.
 

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vermar70

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Apr 8, 2021
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Really nice set up. Two 200Ah batteries in that (smaller) size outside on the frame is a great use of space, and putting them in a tongue box
keeps them out of the weather and away from the eyes of vandals. Good job.
 

Johnjayjrv

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bought 2 lossigy 200ah 12 v batteries April 2021. Made a 12 v, 5.1 kWh battery bank with them for my Rv trailer, using a 200w renogy solar suitcase, Victron 100/30 mppt. They have worked great for me on many camping trips. Have not experienced any problem in charging by solar or AC both chargers Victron. All components fit in a tongue box from harbor freight.
What trailer do you have? That tongue box fit perfect. I have an Alpha Wolf 26dbh-l.
 
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