Aldi xfinity plus 20V Rechargeable Li-ion Battery PT166213302 5irn19/65 2Ah 40Wh teardown

I purchased one of these multi-tool batteries out of curiosity. The moonshot aim is to adapt the pack to operate my laptop, but that's gonna have to wait. In the mean time I had a look inside.

The pack contains 5x Samsung 18650 batteries, which is wonderful because they are quite versatile.

The 20V format also means 18V, depending on manufacturer probably. The voltage varies between full charge and full discharge, but should be somewhere around 5*3.7V or 18.5V on average.

Interestingly, the charger outputs 12V and connects to the thrid pin on the battery pack.

The battery outputs 20V (+).

BTW, Li battery nominal 3.7V x 5 cells ~= 18.5V.

The T pin that's on the battery and the charger I presume is for temperature safety monitoring.


23 June 2017
Found new applications for the battery pack:

1) Portable speaker with d class amplifier module

2) Laptop power. The starting full charge was 20.5V. About 3 hours later power to the laptop was lost in a common manner, with a remaining charge at 16.8V.


6 Nov 2017
Repurposed a Lithium battery charger shell as a reliable battery holder on a powered speaker. The amp module is hidden inside the shell. It's not pretty, but reliable.


brewster said…
Thanks for the informative tear down.

Can't see it in your photos, but does the 2Ah pack have a 'fuel gauge' feature like most recent Li-Ion packs? I bought a new 4Ah pack PT176213302 today and it does. In fact it gives a digital readout of the percentage charge. That is an even more advanced feature than the three-or-four bars used on most packs.

As opened it showed 99% charge. That's surprising because I understood that safety regulations require Li-Ions to be only part charged for transport. Also there's a better shelf life if they are only part charged. It measures about 20.3v on open circuit, which is consistent with being charged to 99% capacity.

Any experience using and recharging the battery? Does it live up to its specs?

I'm guessing the 4Ah pack has 10x cells of 2000mAh. Maybe I'll open it and have a peek.
Bob Newman said…

No fuel gauge on the 2Ah battery. You got a upgrade!

I will be chancing for a discounted 4Ah battery (10 cell unit), or a discounted charger (which I've seen for about $10, and now want to get some to hack as a socket because having a proper socket solves problems if you can get them that are otherwise difficult).

best of luck
brewster said…
Thanks Bob,

Forgot to mention. The measurement of 20.3v DC is taken from + to T. If I measure + to -, I just get a varying and diminishing reading - like what I've experienced as the DC output of a switching power supply with no load on it. What is that about? Faulty battery?

I see you are taking the power + to -, which is also what works for Makita batteries.

I agree about the uses of another charger as a battery host. Will make the whole thing more usable as a 18v DC power supply for projects. Any thoughts whether the 18v source will blow a car USB adapter made for 12v? What other projects do you have in mind?
Bob Newman said…
LOL, Brewster, re the car USB power adapter idea. There is one way to find out :) but I would try it on an ebay cheapie that I was not too attached to.

RE other projects, a bike light comes to mind. Currently I use a 3 cell holder attached to a LED strip. It works on 2 cells but is a bit dim in daylight; 3 is OK; but went connecting the 20V Aldi battery, the brightness is kinda awesome, but the whole thing ends up either too bulky or too flimsy. Laptop power also comes to mind. Said that, I try to be a bit mindful about avoiding making high maintenance oddly balanced Rube Goldberg contraptions -- other people should be able to use it without any instructions.

Have fun with it
brewster said…
Thanks, Bob. I found the USB adapter in my truck is specified as "Input: 12/24v", so that sounds promising.

Another interesting observation. The fine print on the box of the 4Ah battery says "85% more runtime than 2Ah battery". Why only 85% I wonder? Opened it up - same Samsung 20Q cells as in your 2Ah pack, but 10 of them.

Also noticed in the local Aldi today only 2Ah batteries left for sale. Some have the digital fuel gauge and others (older style) without. Lots of chargers, but not discounted.
Anonymous said…
I was wondering if the ALDI 2.0 amp hour and 4.0 amp hour batteries have the same Samsung cells as cells can be 2500mah and higher, I have read somewhere that the 2.0 amp hour cells have higher rated cells than the 4.0 amp hour battery packs?
Any ideas as it gets confusing.
brewster said…
Anonymous: "I was wondering if the ALDI 2.0 amp hour and 4.0 amp hour batteries have the same Samsung cells..."

That's what I reported in the previous comment: "...same Samsung 20Q cells as in your 2Ah pack, but 10 of them."

Where did you read otherwise?
Paul Kuvener said…
Hi there guys?!!.. I stumbled upon this forum/thread/whatever its called lol while doing a bit of research..., I have recently become an 'Electric Razor Scooter Enthusiast'. Having only done a few basic 'mods' to the controller and adding an extra battery in series you get them to run at 36v and the fun increases exponentially lol!.. Anyway next is to ditch the 3 SLA bricks and use Li-ion instead, and i had the idea,to use
2 pairs of Aldi 18v4ah battery packs (2 packs in parallel + 2 packs in parallel, the 2 pairs connected in series) ending up with 36-odd volts needed, and i too had the plan to use the charger shells as mounts. You seem to be knowledgeable on the topic, can you please tell me if it will work?!! I'd be stoked if someone answers! Thanks heaps.... Henri 😎
brewster said…
Re the substitution for SLAs. There is a chance that the protection circuits in each battery pack will object to being connected in parallel or in series. Parallel connections might cause one pack to shut down because the reverse potential looks like a no-load. The serial connection of course requires all current from both packs to go through both packs, which should work at low levels but might cause shutdown for over-current.

Otherwise, I'm not sure what is gained. Will the setup be lighter? More compact? Safer? Easier to recharge?
Bob Newman said…
Hey Henri, sounds like an interesting experiment. I would advise that you be watchful of any serious battery heating, as well as automatic cut outs (as pointed out by Brewster). SLAs can withstand a lot more current (in general), like when you are starting up the scooter from stationary with you standing on it. Also, if I'm reading your intention correctly, with 4 packs (?) there is a considerable waste of space with each pack having it's own shell, board, and associated external connectors, which makes the proposition less enticing than working with a single pack as-is (of 5 cells or 10 cells). I would look around ebay. Anyway, keen to hear how you go. Good luck.
Dean said…
I've also converted an Xfinity charger into a power supply to power a buck/boost power supply module using the 4Ah batteries. A couple of weird behaviours I've seen is that at very low load (< 100mA) the battery shuts down after a minute or so and the output drops to 1.5V. You need to disconnect and reconnect it to restart the battery output. At slightly higher loads (<1A) the battery will shutdown every five minutes for 200ms before restarting itself. However, at high loads (1A or more) the battery runs continuously until exhausted.
brewster said…
Dean's observation of behaviour at small loads is consistent with my finding when trying to measure the open circuit voltage, as reported in the third comment above. That same battery works fine with a normal load.
Dean said…
I ended up gutting a charger and installing a couple of capacitors to buffer the supply over the battery dropout period. I used 2 x 33000uF capacitors, along with two diodes and a 10 ohm resistor to limit the capacitor charge rate. One diode isolates the battery to prevent current flowing back into it from the the capacitors and the other bypasses the resistor when the capacitor is discharging. This works well for loads down to 300ma or so. The battery has a smart controller built in but it is difficult to identify without desoldering the batteries. Interestingly, the Aldi skins only tap off the +/- terminals and don't use the ID or C terminals. The charger only uses +/- and T terminals.

It is also interesting to note that these new batteries don't have individual cell balancing or monitoring like to old ones did.
cameron20020 said…
20v 4ah teardown here:
Bob Newman said…
Thanks cameron20020 :)