my real Battery Voltage：53.84 V at 100% isnt that low?
Seplos CAN BUS RS485 48v 200A 8S-16S BMS
- Thread starter Firechief
- Start date
houseofancients
Solar Wizard
i suggest you do some reading on voltage in LifePO4.
another good resource would be Andy's Youtube channel, search for voltage..
in essence : there is no power above 3.45....
you should never go above 3.6 ( 3.55 preffered ) in day to day charging, or below 2.7 in discharging, as this will prologue cell life at no cost to KWH available
i have a problem my battery 16*lf280k lifepo4 went from 100% to 10 % within 1 hour on low use! (max 500w use)
what i should do.. help please
am using seplos as bms
and it says it only charge 7 kw today
the batteries are brand new from amy(trusted)
here at 16:00
and here at 16:16
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Sanwizard
Solar Wizard
- Joined
- Feb 2, 2021
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- 2,714
The battery seems fine, but I hope you top balanced before putting them into production. It looks like there is an issue with how Seplos is reporting your state of charge. I just received two Seplos BMS's for my 280ah Lishen and CATL DIY 48V banks, so I will be going through this myself soon. Once I have more experience with the settings, I can be of more help.
You must charge the battery with a charger to limit when BMS stops charging. Then must discharge the battery to limit when BMS stops discharging. In the meantime you will get some warnings. When the battery is empty (BMS stopping to discharge) BMS will self calibrate to capacity. The data of 'Total capacity' must be your capacity in Ah and SOC will be 0. In my case, BMS did not set this value. I manually set capacity and SOC over configuration. Now all work OK.
houseofancients
Solar Wizard
did you read the manual ?
the bms needs a one time calibration..
step 1.
top balance your cells till 3.5
step 2.
hookup bms
charge you cells till bms shut off
step 3.
full discharge your cells till bms shut off, without charging (disconnect charger/solar)
step 4.
bms is now calibrated, turn on charging/solar and use normally
can i top balance to 3.65? as i have a 3.65 charger only
houseofancients
Solar Wizard
that would be above the bms cutoff.
you can, but you should let your cells rest for at least 48 hours, so they can return a bit to their nominal voltage of 3.2 .
once they are below the bms cut off, charge till bms cuts off by itself
for top balancing, please use the manual found in the resource section on this forum
can i do that without top balancing? or i should top balance after that ?
houseofancients
Solar Wizard
first top balance, and be prepared that may take a long time.
then rest
then steps 1-4
houseofancients
Solar Wizard
if calibrated properly, the bms will do that for you, and much more fine grained ( as in 279 ah etc)
jsmetalcraft
New Member
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- Jul 7, 2021
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I need help or confirmation on which Seplos to get. 150 amp vs 200 amp. Charge controller is 190 amp max both ways. .5c charge is 140 amps for 1- 280 ah battery. 2P would be maxed at 95 amp each and the option to add another controller if need be. So in my mind 150 amp would be more then sufficient? Is the LCD worth another $20 or for the little more just get it?
houseofancients
Solar Wizard
lcd comes with the 200 amp version.
i always prefer to oversize my bms, as i want to stay well clear of it's limits.
also you would want to size you bms on peak load, it will shutdown when limits are hit
jsmetalcraft
New Member
- Joined
- Jul 7, 2021
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- 185
48v 150A 16S lithium iron phosphate lifepo4 bms monitoring system battery management system with LCD Screen
houseofancients
Solar Wizard
they also have a 200a version
I have a question ... I'm planning to do a DIY 48kW Lifepo4 using Seplos BMS. Using EVE lifepo4 rated at 100AH for battery DIY#1. Then when my budget allows again I will expand and DIY another 48kW battery DIY#2 with Seplos BMS. So I can connect battery DIY#1 and battery DIY#2 in parallel.
My question is -- Is it ok if for battery DIY#1 using EVE 100AH and then in DIY#2 using LISHEN 100AH? They are of different brand but same capacity. Any thoughts on this one. thanks
My question is -- Is it ok if for battery DIY#1 using EVE 100AH and then in DIY#2 using LISHEN 100AH? They are of different brand but same capacity. Any thoughts on this one. thanks
houseofancients
Solar Wizard
shouldnt be a problem
should I also be mindful that the discharge/charge specification of DIY#1 EVE and DIY#2 LISHEN lifepo4 batteries be the same? Or it will not matter as long as their capacities are both the same? thanks
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