Shipping is $15 for up to two. You need just one to get 60A
[$129 plus shipping, USA BASED] 48v 19.2ah 920wh 60A Li-Ion Battery 3200 mAh cells, 13s6p
- Thread starter AmericanElectricSolutions
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CMo44
1 mW
yeah, echoing the other person in the thread that asked if they could buy in person - I'm in LA also. Do you have the ability to allow us to buy in person to eliminate shipping? Thanks!
Gruesome
1 kW
Same here, 15 bucks is worth driving a few miles (about 90, in my case, unless I take the bike....).
Yeah we could arrange a pick up. Dm me
Gruesome
1 kW
What happened?
I just received my battery, and am now in the test phase, doing charge/discharge cycles to measure capacity, and also measuring DC resistance at different voltages/charge states.
For the LG INR18650 MH1 cells I can only find the AC resistance, of 40 mOhm or better, measured on a fully charged cell (4.2V), with 1 kHz. Has anybody measured DC internal resistance for these cells?
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I used these cells (not from this seller) in both of my builds, got a DC IR of less than 38 milliohms on all 1000 of them.
Gruesome
1 kW
Very nice, thank you. I should probably not clutter this seller thread too much. If it's ok, I'll post my charge/discharge curves and DC IR findings when I'm done.
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That looks like it was made in Japan. LG cells. MH1 LH cells.
Can't see anything about the amperage of the BMS though.
I would assume 30, but it's never good to assume things.
Gruesome
1 kW
You are replying to an old post. These things were sorted out in this thread. The thin wires are for protected charging, with polarity protection diodes, a 10 A fuse, and a BMS-controlled FET switch in the charge path. See posts 26 and 28.
The initial for sale post 1 in this thread specifies 60A discharge current.
The initial for sale post 1 in this thread specifies 60A discharge current.
I imagine all those things are long gone.
Who wants to buy some powerful yet funky and huge old controllers?
Gruesome
1 kW
Imagining means not knowing, to loosely quote my old math teacher. 
The battery I just received is almost an inch taller (but same length and width) than another 48V 20Ah nominal/15 Ah measured battery that I recently bought on Amazon (Airuxuan brand). That could be due to a bigger control board, or it could be more padding, or something else. I do not know.
The battery I just received is almost an inch taller (but same length and width) than another 48V 20Ah nominal/15 Ah measured battery that I recently bought on Amazon (Airuxuan brand). That could be due to a bigger control board, or it could be more padding, or something else. I do not know.
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Gruesome
1 kW
As promised (to nobody....), here the results from my first charge/discharge cycles.
At around 50% state of charge, I measure between 35 milliOhm and 55 milliOhm internal resistance per cell. This from observing voltage drops of 60 to 90 mV when a discharge current of about 0.8 A is switched on, for the whole 13s6p battery pack.
At the knee at ~42.5V, internal resistance was measured once at 100 and once at 112 milliOhm per cell.
At 39V, I measured 130 milliOhm per cell.
The pack seems to have the full advertised charge capacity. I actually do measure about 20.5 Ah for both charge and discharge, using the range between 3.0V and 4.2V per cell.
Update: Clearly visible in the bottom graph is the voltage difference between charge and discharge.
Stored energy is 1008 resp. 1010 Wh charging, and 993 Wh for the discharge. The loss between energy in and energy out is smaller than I expected.
I do not know how precise my clamp-on current meter is. I do know that the displayed current depends on the clamping pressure, with about 5% increase when forcing the clamp shut manually, in addition to the spring force. All measurements are for the clamp forced shut.
The initial charge curves, voltage and charge vs time in minutes, charging with a nominal 2A 54.6V charger, actual charging current during the constant current phase measured at about 1.85A. Close to 54.6V the charger tapers the current off, as it should.
Voltage vs charge for
a) the initial discharge from 43.5V (as delivered) to 39V
a) charge from 39V to 54.6V
b) discharge from 54.6V to 39V
c) 2nd charge from 39V to 54.3 V:
d) 2nd discharge from 54.4V to 39V (added):
The second charge curve pretty much exactly follows the first one. The wiggle near full charge (top left; the charge curves are plotted backwards, essentially plotting voltage vs 'charge left to go until full charge') is due to interrupting the charging overnight, and resuming in the morning; there was a 0.4V voltage offset at that point.
The second discharge shows 0.55Ah less charge and 60Wh less energy.
At around 50% state of charge, I measure between 35 milliOhm and 55 milliOhm internal resistance per cell. This from observing voltage drops of 60 to 90 mV when a discharge current of about 0.8 A is switched on, for the whole 13s6p battery pack.
At the knee at ~42.5V, internal resistance was measured once at 100 and once at 112 milliOhm per cell.
At 39V, I measured 130 milliOhm per cell.
The pack seems to have the full advertised charge capacity. I actually do measure about 20.5 Ah for both charge and discharge, using the range between 3.0V and 4.2V per cell.
Update: Clearly visible in the bottom graph is the voltage difference between charge and discharge.
Stored energy is 1008 resp. 1010 Wh charging, and 993 Wh for the discharge. The loss between energy in and energy out is smaller than I expected.
I do not know how precise my clamp-on current meter is. I do know that the displayed current depends on the clamping pressure, with about 5% increase when forcing the clamp shut manually, in addition to the spring force. All measurements are for the clamp forced shut.
The initial charge curves, voltage and charge vs time in minutes, charging with a nominal 2A 54.6V charger, actual charging current during the constant current phase measured at about 1.85A. Close to 54.6V the charger tapers the current off, as it should.
Voltage vs charge for
a) charge from 39V to 54.6V
b) discharge from 54.6V to 39V
c) 2nd charge from 39V to 54.3 V:
d) 2nd discharge from 54.4V to 39V (added):
The second charge curve pretty much exactly follows the first one. The wiggle near full charge (top left; the charge curves are plotted backwards, essentially plotting voltage vs 'charge left to go until full charge') is due to interrupting the charging overnight, and resuming in the morning; there was a 0.4V voltage offset at that point.
The second discharge shows 0.55Ah less charge and 60Wh less energy.
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The packs I received only charge to 54.1v then taper off to 53.9v and bought another one that goes to 54.2 then holds at 54.1. Unsure if the price is worth it. Especially seeings how the first set I bought a few months ago were 25 bucks cheaper and still fully charge to 54.6v.
Gruesome
1 kW
My understanding is that
a) usually/often (depending on the exact cell chemistry ?) there is also a 'knee' in the voltage vs charge curve at the top end, meaning very little charge is gained for the last few Volt on a 13s pack (one can see a hint of a knee in my 7/5 discharge curve, but I didn't measure enough data points at the top end), and
b) supposedly cells last significantly longer if the last 100 or 150 mV up to 4.2V are not used.
So charging to 52V instead of 54.6V for a 13s pack seems very prudent, with very little downside (in lost capacity) and large upside (less aging of the cells).
a) usually/often (depending on the exact cell chemistry ?) there is also a 'knee' in the voltage vs charge curve at the top end, meaning very little charge is gained for the last few Volt on a 13s pack (one can see a hint of a knee in my 7/5 discharge curve, but I didn't measure enough data points at the top end), and
b) supposedly cells last significantly longer if the last 100 or 150 mV up to 4.2V are not used.
So charging to 52V instead of 54.6V for a 13s pack seems very prudent, with very little downside (in lost capacity) and large upside (less aging of the cells).
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Hi Doug,
As I stated in our private conversations, that I can screenshot and post here for everyone to read, I am more than happy to replace or refund if you provide video evidence.
It is standard practice used by most sellers to prevent loss due to misunderstanding of the issues or failed troubleshooting, and we are more than happy to replace defunct products.
Kin
10 kW
Hi! Is there any verdict on the charge rate performance for the 48V battery packs? I have 2 of them, and was wondering if I'll be pushing their limits if I charge at 4A each? I ideally can run in parralel and charge at 8a.
I remember when I bought over a year ago there were some questions about the charge rate ability, but I only finally got to the project that was going to use them. Any advice?
Particularly of interest because I want to charge them in a relatively hot arizona-like environment. They'll be in a box with forced airflow but the ambient air is still elevated.
I remember when I bought over a year ago there were some questions about the charge rate ability, but I only finally got to the project that was going to use them. Any advice?
Particularly of interest because I want to charge them in a relatively hot arizona-like environment. They'll be in a box with forced airflow but the ambient air is still elevated.
Gruesome
1 kW
The specs in the first post say 'max charge rate 4A'. The only 54V charger I have delivers up to 2A.
Also, I don't know whether you read the whole thread, but the two thinner wires are for the protected BMS charging input. See posts 26 and 28.
Also, I don't know whether you read the whole thread, but the two thinner wires are for the protected BMS charging input. See posts 26 and 28.
Hey I'd like to order one. Please message me at your earliest
NVrider
1 mW
I am interested in one
Gruesome
1 kW
He's not the quickest to reply, but from what I have read here, and from my own one-time experience, he will eventually reply. 10 days minus holiday weekend makes it sound a bit less worrisome.
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