Cheap Lifepo4 battery pack on AliExpress 12V, 25AH

Dave Bert

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Ran across a Lifepo4 battery pack on AliExpress. It is 12V, 25AH for $142CAN or about $110US with free shipping. It can easily be converted to use as a power bank. I don't know if it is permissible to post direct link to a vendor. The brand is Mr.Li in the Slenergy Store.
 

gabilondo77

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Viofo A129 Duo,Viofo A129 Pro Duo 4K
Have you test it?The tests I saw on chinese branded battery packs show 50-60% of advertised capacity.
 
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Dave Bert

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I just received the unit a couple of weeks ago. Canada Post is really slow when it comes to packages from China. I did do a few test at home. I was able to run my A129 duo for over 60 hours continuously, 6 hours more in buffered parking mode. My USB tester shows around 31,000mAh or 101Wh.

To my surprise, it came with a charger, 12V, 6A with a noisy fan in a very cheesy box and a jumper cable on a EC3 connector with a diode pack. The unit draws 5A initially with flat batteries and settles to 3.5A in a few minutes, and it takes about 5 hours to fully charge the unit.

There is a EC3 connector on the box and a capacity meter that is directly connected to the battery. The 12V cigarette lighter output, binding posts and 2.1mm barrel connector goes through the BMC board.

Cannot tell what kind of batteries and capacity they are because it is shrink wrapped. But can confirm that they are LifePo4 batteries from the discharge voltage.

I would give the build quality a 5 out of 10. When I have more time I will redo the wiring and put heat shrink on all the soldered connections. Here are a couple of pictures of the unit and of the capacity meter, I had to set it to LifePo4 because it came set to lead acid giving me wrong capacity readings.

IMG_20191021_133904.jpgIMG_20191021_132514.jpg
 
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Nigel

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3.5A * 12V = 42W, in 5 hours that would be 210 Wh, but you say it only stores 101 Wh, so maybe it only charges at 20W.

42W charge rate is quite useful, 20W is a bit slow, it would be nice to know which it is closest to... I guess it is the faster rate if you are getting over 60 hours from an A129 Duo and your USB meter is not measuring accurately...
 
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Dave Bert

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The charging current drops off as the batteries are brought up to full charge. I did not keep track of the current over the 5 hours, just the initial current and noted when the charger stops charging indicated by its LED starts flashing and the fan stops running. It is not a constant 3.5A for the full 5 hours, it is a constant voltage, not a constant current supply.
 
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gabilondo77

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It's advertised to approx.300Wh.You get only 101Wh?
 

dunno dashcam

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I looked for a cheap alternative for my bicycle so I bought one of these. Under $30.00 AUD. Weight is around 1.5 kg.

I run two cheap navigator 8 cams on it for 5 hours. Ok there is a bit of weight there but it allows me to use dash cams that start same as in a car. They automatically override their footage correctly and with a 32 meg card are hard to beat.

I am over action cams that cut of after an hour.

I mean if I go shopping with the bike I often cay 10- 12 kg of goods so what is an extra 1.5 for the battery. Going hard...just select a lower gear, right..... :)

 
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