Aldi xfinity plus 20V 2Ah 40Wh rechargeable Li-ion battery PT166213302 5irn19/65 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 :)
Hello Bob.

I am also doing some research for some DIY projects with tools batteries.

I would like to ask you a few of questions.

Do the Aldi xfinity batteries have some sort of low voltage cutoff protection in the actual pack?

As far as I can see the tools only tap directly from the + and - poles unlike other tool brands that have an extra pole to communicate with the tool and disconnect on low voltage or high temperature. So am I correct in assuming that the battery cuts the supply when it reaches certain threshold while still avoiding damage from draining the battery too low?

What sort of voltage do you get from a "fully discharged" battery?

Now, without being an expert. I think Henri's idea is feasible and plausible. Other tool brands have multi battery tools these days. Ozito (rebranded Einhell these days) and Makita have some skins that work on 36V by combining two batteries.They warn that the batteries need to be of the same type, capacity and fully recharged. I presume it is because they become in effect a 2S type to obtain the 36V at whatever Ah they are.

As a matter of fact there are a few examples online of such beasts. The one I consider most remarkable would be a home made electric bicycle with 6 Dewalt 20V batteries connected in a 3S2P configuration to achieve 60V 10Ah. Have a look at it:

By the way, he is selling it at the moment and it is a thing of beauty with that finish:

I am kind of sad that I think I overcomplicated my project but now 85% of the parts are ordered so I will have to bite the bullet and finish it. But I want to have an alternate plan for version 2.0 when the time arrives.

I found the chargers at $10 today in Aldi. They are coming back this Saturday so I picked two and a 2Ah battery to do some tests.

If my tests are successful I will be picking up 7 chargers and waiting for the 4Ah batteries on Saturday.

I figured, like you did, that cannibalising some chargers to be used as sockets as it ends up being cheaper than getting them 3d printed. That way I can also keep all the internals of the charger as spares for the 3 that I will use as chargers.

I am charging the battery right now to test. I'll report back my findings.

Also. Checking out the images of the opened battery I noticed that they seem to have what appears like an USB socket circuit printed on the board.

That means that an usb port may be hacked into the battery to use it as a power bank maybe.

Reporting my findings.

The battery seems to have an internal cutoff circuit. Once it hits 10V it cuts the power off until you disconnect and reconnect. Once it cuts off under load it bounces back to 15V which is a healthy low level for the cells.

The gauge goes to 0% under load but goes to 5% when it cuts off. This is consistent with the percentage readings described above.

When I ran the same test with Makita batteries they kept going down as it is a third pole in the tools the one that either send the signal or take the reading that makes the tool cut off the power. With Makita LTX batteries is the tool and not the battery the one that shuts the power down.

So seeing that the 4Ah will cost $40 compared to $120 for the Makita ones, that the cells in the Aldi batteries are Samsung instead of TenPower for the Ozito ones and that they have an integrated LVD (low voltage disconnect) of sorts. I think we are onto a winner here and I am buying a heap on Saturday.

I am pretty sure that the Ozito Power X change also have the LDV integrated and the good thing about those is that you can actually buy them any day at Bunnings, the price is similar at $40.39 but the charger is a bit more expensive and the multi charger is $53. I can get 5 chargers from Aldi discounted and have coins for the trolley.
I forgot.

The port in the photo seems to be an active USB. What sort of Amps can be pulled from it is the question. I wouldn't think it is a 2.1A so maybe just a 1A but without soldering and testing I can't say.

Photo showing the 5V reading:
It is me again.

I wouldn't be me if I went to bed without checking the USB port that is in the battery circuit board.

Anyway. It is just 1A as you can see in the photos:

It may be good for some people for a low powered device. I don't think I can be bothered using it for anything.

What I would like to do would be either making a power source with USB and a 2.1mm socket for 12V and 18V output or adapting an existing one from a different brand like the Makita:

The Milwaukee:

Or even the Ozito (Which would be easier to adapt I think) although this one is just USB and is missing the power socket.

I hope this extra information gets you guys as excited as I am of the possibilities of these batteries.
brewster said…
Willmer, that's fascinating. I cannot add anything useful to my earlier posts because I have done no more exploring since then and I cannot answer your questions with any authority. I do have a couple of these batteries and chargers on hand for projects, which I picked up cheap when they were remaindered at Aldi.

Yesterday there was an big heap of the chargers still at our local store at $10 or so, but I guess they will pull them from display soon, to put the price back up when the next lot of tools is in the catalog. Best of luck with your project.
This comment has been removed by the author.
And of course I am back here today.

I went to Aldi and got the amount of chargers I needed for my project.

Back home I gutted one and installed a boost converter inside the casing. It actually fits on the original screw holes of the charger PCB. These chargers are very easy to work with and light.

The converter is one of these guys:

The next step is to pair two gutted chargers with one converter and wire them in parallel to have a 20V 8Ah or 20V 4Ah (I now this one is basically silly) to be able to run my lights for long periods of time. And have the convenience of the rapid chargers.

I guess the same process can be done to convert the charger to a 12V power source by installing a buck converter instead.

After checking thingiverse I think there are very good chances of also making the adapters to run my Makita tools with these batteries. I have been putting off buying a couple more because that is over $200 for just two batteries. When you can get 6 Aldi ones for the same money.

Brewster the next lot of these are coming this Saturday 14/07/2018 and I'll be there stocking on batteries. I love the 60 days money back guarantee.

Here are the photos of today's hacking and repurposing.
Stuart Bradley said…
I bought one of these after seeing on here that they use samsung 15a discharge cells, so your initial teardown is greatly appreciated. My use is just repacking drill battery packs in general. I keep fixing up my old drill with li-ions as its cheaper and easier than replacing.

I was surprised also to see that these aldi packs don't have cell balancing. I normally use my hobby charger to charge my drill packs, and just put on a balancing connector to plug into the charger to deal with that. This time around though I was planning on having the charging circuitry within the battery pack also (will stop over discharge etc), and since the aldi pack doesn't have balancing I thought of using the circuity off an Ozito pack I have laying around (pinched the cells to fix a portable vacuum cleaner).

Does anyone know of the charger output on the Ozito chargers?

Anyone know if the NTC connection needs to be used to charge the pack?

I also really like the % battery reading on the aldi pack. Anyone know what the wiring refers to? Some are obvious, others not.

I was surprised, the usb solder pads on my pack don't do anything yet I noticed someone else on here had 5v output with them. I was tempted to use that for certain applications, but if doesn't work then its not much help.

Thanks again for your work posting this, and I appreciate any help anyone can give

Paul Kuvener said…
Wow, since i was last here this thread has grown hugely!.. Looks like a lot of really useful information for me to read over re. my query about using Aldi/Ozito Li-ion batteries for my e300. I would just like to quickly apologise to all the people who answered me for my sudden disappearance exactly 6 months ago... umm, unfortunately i was on an 'involuntary vacation' in Cessnock jail lol! (No btw im not a serial killer, it was for driving whilst disqualified - 7th offence lol.. hence the scooter thing!).. So yeah Bob, Brewster, Dean, Willmer, thankyou for all you guys' insight, and again im sorry for just vanishing!... Im looking forward to getting back to the fun, and i'll post my achievements/failures lol here.. Cheers guys... Henri
Unknown said…
Hi guys I tried to 20v4ah packs in series in an e300 scooter but no joy, wouldn't drive the wheels. Should I be connecting + and -, or + and T??
The +and - give a diminishing voltage reading it's very strange.
Anonymous said…
The protection circuit probably doesn't like them running in series. Might have to bypass it it you want to use them that way - with obvious risks.