meetyg
Solar Enthusiast
- Joined
- Jun 4, 2021
- Messages
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[Update] It seems to have low temp charging protection! See my update on this:
I have recently recieved the 12v 20Ah battery ordered from AliExpress.
I got it for $93, and free shipping. I was expecting it to take a few months to arrive, but I got it about a month and a half since ordering.
I am going to use it for a small project of mine, which you can read about here:
Anyways, I had the chance to test it during the weekend and so I'm writing a little review.
Unboxing:
It came fairly well packaged.
Its a bit larger than I imagined, but the dimensions are correct as advertised.
I was impressed with the build: it seems solid and the ABS plastic felt like good quality.
I was hoping to be able to open it and peek inside, but the top part is fairly well glued on. Since I plan on using this battery, I wasn't in for a full tear-down.
I suppose they are using some form of cylindrical Lifepo4 cells for this size.
The terminals are fairly small though, with short screws. I guess that for a 1C discharge rating, they are enough.
Charging:
The voltage was at 13.17v when unboxed, so I assumed around 40% SOC.
I started charging using my PSU set to 14.6v connected directly to the screws. I noticed that when I increased the amperage to 10A, the screws got pretty hot and the voltage reading on the PSU was incorrect. So I just added some bus bars to get a better contact. That fixed the heating and inaccurate voltage reading.
I am using the original "crocodile" wires that came with my PSU, so they might not be ideal for such amperage, but I just wanted to get along with the testing.
So after fully charging (took a few hours) the PSU showed no current flowing at 14.6v.
Even at 10A charging (0.5C) the battery was still cool to the touch, with only the terminals and bus bars being a bit warm. Nice
Capacity Test (the interesting part...):
I let the battery sit for about half an hour. I checked the voltage and it was around 13.9-14.0v. Then I started capacity testing at 0.2C (4A) with my battery capacity meter. I disabled the under-voltage protection of the battery tester, so that I would get as much capacity as possible until the battery's BMS would cut-off.
After a few hours the BMS cut-off at about 10.8v.
The results were disappointing: only 17.4Ah
I was expecting at least 18Ah...
Anyways, I thought that maybe my testing wasn't accurate enough, or maybe I didn't charge it up all the way.
So I did another charge-discharge cycle. This time I connected a simple shunt, and charged the battery up again. After the PSU showed no current, I connected a small 3A Lifepo4 charger I had, just to make sure. When the small charger showed a green light (not much after connecting), I let the battery sit for around 20 minutes.
The shunt showed 17.3Ah went in during this charging session.
Then I reset the shunt and the capacity meter/tester and ran the test again at 0.2C / 4A.
The results were almost the same: 17.5Ah as both the shunt and capacity tester showed.
Summary:
This battery is under the advertised capacity, unfortunately. Even if the BMS cuts off at around 10.8v I should have gotten at least 95% capacity, but in reality I got 87% capacity. I am guessing that maybe the real capacity of this battery is 18Ah, not 20Ah as advertised.
But... For the price and nice build quality I am somewhat still pleased with this buy!
There are a few similar batteries of this type on AliExpress, branded under different names. You can get one for around $88 now with Black Friday sales, and sometime free shipping depending on your location.
I am opening a dispute on AliExpress, requesting a partial refund because of the lower capacity.
If someone here thinks that I didn't test correctly, I will be happy to hear and try again. From my knowledge, usually Lifepo4's outperform their rated capacity for the first few cycles, but this one under-performed.
I haven't had a chance to do a 1C discharge test, or over/under temp. testing either.
If someone is interested, I could do some more testing... just let me know. For my use its enough (not worried about under-temp).
Hope you enjoyed!
[Review] Cheap 12v 20Ah Lifepo4 from Aliexpress (with low temp protection)
[Update] It seems to have low temp charging protection! See my update on this: https://diysolarforum.com/threads/review-cheap-12v-20ah-lifepo4-from-aliexpress-with-low-temp-protection.31939/post-389593 I have recently recieved the 12v 20Ah battery ordered from AliExpress. I got it for $93, and...
diysolarforum.com
I have recently recieved the 12v 20Ah battery ordered from AliExpress.
I got it for $93, and free shipping. I was expecting it to take a few months to arrive, but I got it about a month and a half since ordering.
178.0US $ |New 12V 20AH Lifepo4 Battery Pack 20AH Lithium Iron Phosphate Bulit in BMS DIY 12V 24V Battery For Boat Motor EU US TAX FREE|Battery Packs| - AliExpress
Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com
I am going to use it for a small project of mine, which you can read about here:
[Project] Extending EV range by offsetting auxiliary 12v loads using solar
Well, I have this crazy idea that came up a while ago, and now I'm going forward to implement it. The motivation is like this: We all love solar, many of us like/have EVs. We would love to put some solar power to use in order to extend our EV range. But as some of us know, connecting solar to...
diysolarforum.com
Anyways, I had the chance to test it during the weekend and so I'm writing a little review.
Unboxing:
It came fairly well packaged.
Its a bit larger than I imagined, but the dimensions are correct as advertised.
I was impressed with the build: it seems solid and the ABS plastic felt like good quality.
I was hoping to be able to open it and peek inside, but the top part is fairly well glued on. Since I plan on using this battery, I wasn't in for a full tear-down.
I suppose they are using some form of cylindrical Lifepo4 cells for this size.
The terminals are fairly small though, with short screws. I guess that for a 1C discharge rating, they are enough.
Charging:
The voltage was at 13.17v when unboxed, so I assumed around 40% SOC.
I started charging using my PSU set to 14.6v connected directly to the screws. I noticed that when I increased the amperage to 10A, the screws got pretty hot and the voltage reading on the PSU was incorrect. So I just added some bus bars to get a better contact. That fixed the heating and inaccurate voltage reading.
I am using the original "crocodile" wires that came with my PSU, so they might not be ideal for such amperage, but I just wanted to get along with the testing.
So after fully charging (took a few hours) the PSU showed no current flowing at 14.6v.
Even at 10A charging (0.5C) the battery was still cool to the touch, with only the terminals and bus bars being a bit warm. Nice
Capacity Test (the interesting part...):
I let the battery sit for about half an hour. I checked the voltage and it was around 13.9-14.0v. Then I started capacity testing at 0.2C (4A) with my battery capacity meter. I disabled the under-voltage protection of the battery tester, so that I would get as much capacity as possible until the battery's BMS would cut-off.
After a few hours the BMS cut-off at about 10.8v.
The results were disappointing: only 17.4Ah
I was expecting at least 18Ah...
Anyways, I thought that maybe my testing wasn't accurate enough, or maybe I didn't charge it up all the way.
So I did another charge-discharge cycle. This time I connected a simple shunt, and charged the battery up again. After the PSU showed no current, I connected a small 3A Lifepo4 charger I had, just to make sure. When the small charger showed a green light (not much after connecting), I let the battery sit for around 20 minutes.
The shunt showed 17.3Ah went in during this charging session.
Then I reset the shunt and the capacity meter/tester and ran the test again at 0.2C / 4A.
The results were almost the same: 17.5Ah as both the shunt and capacity tester showed.
Summary:
This battery is under the advertised capacity, unfortunately. Even if the BMS cuts off at around 10.8v I should have gotten at least 95% capacity, but in reality I got 87% capacity. I am guessing that maybe the real capacity of this battery is 18Ah, not 20Ah as advertised.
But... For the price and nice build quality I am somewhat still pleased with this buy!
There are a few similar batteries of this type on AliExpress, branded under different names. You can get one for around $88 now with Black Friday sales, and sometime free shipping depending on your location.
I am opening a dispute on AliExpress, requesting a partial refund because of the lower capacity.
If someone here thinks that I didn't test correctly, I will be happy to hear and try again. From my knowledge, usually Lifepo4's outperform their rated capacity for the first few cycles, but this one under-performed.
I haven't had a chance to do a 1C discharge test, or over/under temp. testing either.
If someone is interested, I could do some more testing... just let me know. For my use its enough (not worried about under-temp).
Hope you enjoyed!
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