Jay, I do not know/use this brand. Got this off the internet. Looks to
me like they are telling you max charge is 100A but max life is 30 - 50a
charge.
only a 5 year warranty so.... Good Luck !
Voltage 51.2V
Capacity 100Ah
Charging Voltage (Bulk/Absorb) 56.2V (+/- 0.2V)
Float 54V (+/- 0.2V)
Low DC Cutoff 47-44V (depending on load - start high, lower if needed)
Charging Current Max Constant Charge: 100A (30-50A recommended)
Discharging Current Max Constant Discharge: 100A
Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail [email protected]
text 209 813 0060
On 2023-06-27 2:01 pm, Jay via RE-wrenches wrote:
These are 100 amp hr eg4 48v batteries.
Tech support said their recommended charge rate per battery is 30-50
amps.
I asked because Ive never heard this and it still doesn't sound
correct.
All of the responses have been consistent and I will try to get someone
higher up to review all this and report back
Thx
Jay
On Jun 27, 2023, at 10:07 AM, Starlight via RE-wrenches
<[email protected]> wrote:
Hi Steve,
My experience is different. First, I don't know of any stationary
battery systems that have C2 charge ability, many not even C1. A 20kWh
bank C2 rate would be 40kW or over 770Amps @ 52V. I have 10 years
experience with Li batteries, (hundreds of Li installations, mobile and
off grid), and thousands of LiFeBlue Battery customers, low current
charging works without issues. Most of these systems charge at the high
end 0.35 C rate or less. Jay did not mention the bank size so we don't
know the C rate for the 30-50 Amp recommendation. But I guess it is far
lower than 1C.
Long absorb (CV) times may cause a cell to saturate resulting in rapid
voltage rise and the BMS protection inhibiting input current. This
sudden loss of load (essentially a battery disconnect) can cause havoc
with some inverter/chargers and PV solar controllers. In our
experience, the best method to set Absorb times for any Li system is by
trial. If the cell voltages are staying relatively close during
discharge (6mv in the attached image), then balancing time (> 3.55V CV)
is sufficient, whether it is 0.1 hours or much more.
Larry Crutcher
Starlight Solar Power Systems
(GM, LiFeBlue Battery)
<32ED5403-8A66-4ED5-AFFD-E308D5FC48C6_1_105_c.jpeg>
On Jun 27, 2023, at 6:33 AM, Steve Higgins via RE-wrenches
<[email protected]> wrote:
For many LFP batteries, while some say you can charge at the C1 Rate,
most want you to charge at the C2 or C3 rate.
While you don't have to get them full all the time like lead, as long
as you are cycling regularly, it is still a good idea to get them to
full regularly. Now if they are a backup system or not being cycled,
they should not be held to full all the time. This can accelerate
damage to the cells.
Where we see the major mistakes are the absorb timer settings. Too
many people are setting the absorb timers too short, especially if they
have parallel modules and are not running closed-loop communications,
or the batteries can't communicate with each other or the chargers.
In these cases where you have 2,3,4... more batteries in parallel, the
absorb timers can help balance them as the batteries that don't need
balancing stop charging, while the cells that need the extra time get
that time if you have longer absorb timers.
We advise for our LFP drop in's that you have the following. Assuming
that you are charging at least the C2 Rate.
1 Parallel Connection = 30-45 mins absorb timers.
2 Parallel Connections = 45-60 mins.
3 Parallel Connections 60-90 mins.
4 Parallel Connections 90-120 mins
[1]
Steve Higgins ⋅ Technical Services Manager
t +1.902.597.4020 m +1.206.790.5840
f +1.902.597.8447 e [email protected]
[2] [3] [4] [5]
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On Mon, Jun 26, 2023 at 6:51 PM Darryl Thayer via RE-wrenches
<[email protected]> wrote:
Hi Jay, Larry says is correct. My experience, with cells and there BMS
is they need to get up to top balance voltage then the BMS will stop
charging the full cells and bring the remainder of cells up to fill
charge. My oldest set is about 6 years old, since I understood they
have been fine
On Mon, Jun 26, 2023, 3:58 PM Jay via RE-wrenches
<[email protected]> wrote: Hi All
I'm wondering if minimum charge amps for lithium is common or not?
Or does it have to do with the cell shape: cylindrical vs prismatic vs
pouch?
A client purchased some EG4 batteries and they are getting a bit out of
balanced. Tech support didn't suggest higher volts or longer absorb but
did mention they need 30-50 amps charge. It's not in the manual.
Wondering what you all think and know
Thx
Jay
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