EEVblog Electronics Community Forum
Products => Other Equipment & Products => Topic started by: Gyro on June 04, 2019, 01:00:34 pm
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Time for a quick teardown as I haven't done one for a while.
I noticed that my local Lidl UK store had packs of spare 20V 2AH power tool Lithium batteries, complete with chargers for £17.99. This is a bit unusual as normally the charger comes with the tool and you can only buy the spare battery packs.
I didn't give too much thought to whether I could do any better from ebay, Amazon etc. but this looked like a good opportunity to get a portable supply for my TS100 Iron and maybe a few other things. Also they're of known quality, TUV/GS etc. There is a 3 years warranty on the charger and 6 months on the battery (reasonable I suppose given the potential for abuse). At least the rated capacity of the 16550 18650 cells looks plausible for their size and not inflated like many you see.
The charger is a 65W 1 hour fast charger with 2.4A output capability.
Everything is easy to disassemble, with Hex socket head screws. The little three level battery gauge PCB (see photo) is clipped to the top molding, but everything else, including the connector, remains with the base. The contacts are +Ve, -Ve and Thermistor (seen in the underside shot). There is a fourth contact on the battery pack but it appears unused, the charger only brings out the 3 pins.
As can be seen from the battery pack PCB, it includes cell balancing and charge protection. There is also a chunky sheet metal fuse (F1). I don't know if this might be used as an overload current shunt too, probably not. As previously mentioned, there is a thermistor glued to one of the cells on the underside.
Initially I was intending to fabricate a connector to slide into the normal housing slots and contacts but, having opened it up, it looks like there is plenty of space for me to add a small DC connector (and additional lower current fuse!) which will make connection a lot easier. F1 looks rated for very high motor current.
I also opened up the charger, again four socket head screws and one screw holding the centre of the PCB down. It looks to be of decent quality, with good layout and proper safety approvals on critical components, including the fuse. The underside view shows very generous PCB safety clearances, both on the primary side and primary - secondary. The only minor criticism is that the mains lead inner wire insulation could possibly catch on the underside of the PCB, if not routed correctly. There's no danger of secondary side contact anyway. I won't be doing any further inside, this was purely a safety check.
I hope this will be of use to somebody. Of course, you need to be very careful when playing with Lithium battery packs and modifying it in any way will violate the terms of use. You have been warned!
Photos attached...
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The dual voltage batteries are a bit more interesting:
https://www.youtube.com/watch?v=2d6iggXptNc (https://www.youtube.com/watch?v=2d6iggXptNc)
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Interesting video, I was wondering how their 20/40V stuff works, no way to see in the store.
Yes, the 20V and 20/40V batteries are charger are also happen to be available in Aldi (UK) stores at the moment (Aldi and Lidl tend to track each other with the timing of their offers). I did consider these but from what I remember, a 20V battery and charger (sold individually) would have come to about £35, so I didn't pursue it any further.
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https://lygte-info.dk/review/batteries2012/Parkside%20INR18650E%202000mAh%20(Blue)%20UK.html
Not bad. Appears to be rebranded Samsung cells.
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That's a lot more comprehensive performance data that I could have expected to find, Thanks! :-+
Looking at the latest upcoming offers listing they're back in on the June 16th (although still seem to be around in some stores from last time). They also list a 4AH version (battery only) for £25. No 20/40V option though. https://www.lidl.co.uk/en/MiddleofLidl.htm?id=1094&week=2 (https://www.lidl.co.uk/en/MiddleofLidl.htm?id=1094&week=2)
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Yay, we have portable power!
DC connector, protected by 2A fuse, fitted. There's no interference with normal usage.
Hint: Don't pick the largest bodied 3.5 x 5.5mm DC jack that it's possible to buy! It took a lot of 3D eyeballing! :palm:
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Hi, welcome to the forum.
I connected to the exposed PCB areas that are directly connected to the two outer contacts of the battery connector, not directly to the cell connections [EDIT: Looking at the PCB photo, it looks like P5 (Cell5) and P19 (the connector side of the big fuse, F1), double check the polarity before connecting the TS100!]. As I mentioned, because I was using a relatively fragile (at least, easily shorted) DC connector, I fitted small in-line 2A fuse inside the battery pack. I also use a plastic cap to shield it when not in use.
As I mentioned, if taking this approach, check very carefully before drilling a connector hole - what looks like plenty of internal space quickly evaporates when you start visualising in 3D on assembly.
If you have access to a 3D printer, I have since found that there are better ways of achieving the connection. I wish I had found these before! ...
https://www.yeggi.com/q/parkside+x20v+battery+adapter/ (https://www.yeggi.com/q/parkside+x20v+battery+adapter/)
I hope this helps.
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Yes, that's right. The contacts are always live. Any discharge limiting is done by the power tool.
I recommend using Ralim's alternative firmware on the TS100, this includes battery operation options to prevent discharging of the battery pack below its safe limit...
https://github.com/Ralim/ts100 (https://github.com/Ralim/ts100)
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I bought these to replace my 5 year old Lidl impact drill batteries.
https://a.aliexpress.com/_BU7rB1
They are working very well. The old batteries developed high internal impedance, around 120mOhm, that caused the voltage to drop a lot and trigger the overdischarge protection.
This ones hold nicely 20amp loads (measured when applying load to the drill)
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Does someone have an idea where I can find these connectors. They have a pitch of about 8mm/0.3inches, and everywhere i look the biggest seems to be 5mm (I need the battery side of the connector).
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Hi Gyro,
sorry for exhuming up this discussion :-DD
on the battery charger i can see three pin (+, -, ID)
what does stand for ID ? Means that in the battery there is an encrypted chip or a 'particular' resistor that is used for recognize original parts ?
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Hi Simon, welcome.
Looking back at my charger PCB photo, I see + - and T, which I assumed was Thermistor, but you are correct, the charger molding says ID. Your question prompted me to wonder whether there might be an ID pin to differentiate between the 2Ah and 4Ah batteries but I just checked the slot voltages, and resistances to the negative terminal of both sizes of my batteries and they read the same.
I would be surprised if Lidl had implemented detection of 'non-genuine' batteries, but given the price point I would think it unlikely, that's more Festool / Makita territory. I can't say for sure of course, I haven't managed to find any data on the cell balancing (/controller?) IC.
Battery cut-off is implemented in the power tool itself, presumably from voltage level - the outer slots on the battery connector are permanent battery voltage. The power tool uses the alternate inner connector slot to the charger, The molding indicates 'T' which makes sense as an overtemperature protection from the thermistor on the battey pack under heavy use (more logical than it's use on the charger).
I haven't pulled apart any of my power tools to investigate the controller, Big Clive had pulled the soldering iron apart...
https://www.youtube.com/watch?v=KPJJBa6-TVQ (https://www.youtube.com/watch?v=KPJJBa6-TVQ)
... but being a low drain device, it doesn't appear to use the T pin. Clive has also pulled apart a couple of Aldi 20/40V tools but that's probably of little use.
I had one 2Ah battery failure a while back (ithe charger refused to charge it) - I remember I had stalled the tool a few times, I should have used a 4Ah one. I'm slightly ashamed to say that I didn't bother to pull it apart and investigate - they happened to be on the centre isle offers that week so I returned it for refund and replacement. In hindsight I wish I had made more of the opportunity - I'm slipping.
Sorry I can't give you something more concrete.
EDIT: Looking again at my photos, I just noticed the same LG18P22A IC on the underside of the charger PCB as is fitted on the battery pack, together with RST, SCL and SDA on the silkscreen. That would indicate that they are microcontrollers and there is some comms going on (with the charger anyway) - most likely a 'cells out of balance indication. Latched or not, I don't know.