Frnc wrote: ↑Mon Nov 21, 2022 6:20 pm
Anyone know of a 18650 tester that tells you immediately what % of capacity it's at? I have a charger that tells you, but I charged the batteries in the radio, put them in the charger, and started counting up from zero again! I was scared of overcharging as the radio said they were already full, so I took them out.
The chemistry allows an approximation to be made from the voltage (as opposed to NiMh, which don't lose voltage in a linear fashion as they run down). Measure the voltage when the cell has been standing for a few hours or so (straight out of the charger the voltage will be slightly higher than "resting" voltage). 4.2V ish, is fully charged, about 3 is empty. Over 4.25 or below 3v is quite bad.
What charger do you have? If both radio and cjarger have correct electronics (lots of things don't!), then neither will over charge as they use Constant Current/Constant Voltage algorithm - apply eg.500ma to the cell until it gets to a certain voltage, then use the full cell voltage (4.2v) and reduce the current until 0ma.
This info good to know in a rolling blackout situation, your chargers will charge a flat lithium cell faster (in the Constant Current part of the charge cycle) than one that's almost full (reducing current while in Constant Voltage part of the algorithm).
Cheers. I tried them in the charger again and this time one said "FULL" immediately, and the other did a few seconds later. I think I did charge them a bit more in the radio since last time I had them in the charger, but only as a topup, as I think I fully charged it before. So no real explanation as to why it showed the charge coming up from zero. Maybe they weren't quite 100% charged, and it takes a few minutes to get a reading if they aren't full. The charger is this...https://smile.amazon.co.uk/gp/product/B07DNNY8HF/
Anyway, the charger and the charging in the radio both tally now, when they are full. I'll turn the torch on for an hour and try again. Ideally lipo batteries shouldn't be charged fully.
OK, so I left the radio's torch on for about an hour. Put the batteries in the Xtar charger. One still says FULL, one back to counting up from zero (!). Put the full one in the radio. Interestingly, torch and radio both work with just one battery in.
Warning. For these radios that have little screws holding the batter cover on. I lost one screw and stripped the thread (screws into plastic) on one side. Will be gentle from now on. Otherwise it's gaffa tape job.
Back to the battery, it's been charging for a few minutes. Voltage is high, was higher than the full one showed second time around actually, but it's still only showing 150 mAh out of 2000 supposed capacity. Going to keep checking and try to see what it reads just before full. At full you don't get a number. Seems like the radio uses one battery before the other, or maybe it's the state of the actual battery. Eventually I'll buy a couple of spares anyway.
Frnc wrote: ↑Tue Nov 22, 2022 10:30 am
OK, so I left the radio's torch on for about an hour. Put the batteries in the Xtar charger. One still says FULL, one back to counting up from zero (!). Put the full one in the radio. Interestingly, torch and radio both work with just one battery in.
Warning. For these radios that have little screws holding the batter cover on. I lost one screw and stripped the thread (screws into plastic) on one side. Will be gentle from now on. Otherwise it's gaffa tape job.
Back to the battery, it's been charging for a few minutes. Voltage is high, was higher than the full one showed second time around actually, but it's still only showing 150 mAh out of 2000 supposed capacity. Going to keep checking and try to see what it reads just before full. At full you don't get a number. Seems like the radio uses one battery before the other, or maybe it's the state of the actual battery. Eventually I'll buy a couple of spares anyway.
If it's a device using two 18650 batteries and will run on one, or the other, then the batteries are running in parallel. i have some lamps like that. If both are in, then it flattens them both together, but they last twice as long. Best to use them or have them installed at the same time so that they will always be in the same state of charge.
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought
Frnc wrote: ↑Tue Nov 22, 2022 10:30 am
OK, so I left the radio's torch on for about an hour. Put the batteries in the Xtar charger. One still says FULL, one back to counting up from zero (!). Put the full one in the radio. Interestingly, torch and radio both work with just one battery in.
Warning. For these radios that have little screws holding the batter cover on. I lost one screw and stripped the thread (screws into plastic) on one side. Will be gentle from now on. Otherwise it's gaffa tape job.
Back to the battery, it's been charging for a few minutes. Voltage is high, was higher than the full one showed second time around actually, but it's still only showing 150 mAh out of 2000 supposed capacity. Going to keep checking and try to see what it reads just before full. At full you don't get a number. Seems like the radio uses one battery before the other, or maybe it's the state of the actual battery. Eventually I'll buy a couple of spares anyway.
If it's a device using two 18650 batteries and will run on one, or the other, then the batteries are running in parallel. i have some lamps like that. If both are in, then it flattens them both together, but they last twice as long. Best to use them or have them installed at the same time so that they will always be in the same state of charge.
Well I did, but after an hour with the torch on, one battery showed full and the other empty. I thought maybe it was nowhere near empty, and that the charger would quickly show a much higher reading. After about half an hour it was only showing 280 mAh out of 2000 written on the battery. Then I forgot for a bit and when I looked again it was showing full, and I noticed that it was flashing a number in between, which was 400 or so, so these batteries I think are not too good. I'll buy a couple of spares next month.
If it's a device using two 18650 batteries and will run on one, or the other, then the batteries are running in parallel. i have some lamps like that. If both are in, then it flattens them both together, but they last twice as long. Best to use them or have them installed at the same time so that they will always be in the same state of charge.
Well I did, but after an hour with the torch on, one battery showed full and the other empty. I thought maybe it was nowhere near empty, and that the charger would quickly show a much higher reading. After about half an hour it was only showing 280 mAh out of 2000 written on the battery. Then I forgot for a bit and when I looked again it was showing full, and I noticed that it was flashing a number in between, which was 400 or so, so these batteries I think are not too good. I'll buy a couple of spares next month.
Odd. It sounds like one of the batteries is faulty, though those battery capacity meters are not always too accurate.
Maybe try switching the two batteries around to see if the same one goes flat first? And check the contacts are good and clean.
We don't see many devices using 18650's, though some vapes use them? Let us know if you get a good price/capacity. Take stated capacity with a big pinch of salt
Beware Chinese 18650s. Also beware any that state capacity over 3500mAh.
One really good test for the better battery is to weigh it. >44g for the better ones: <40g for the rubbish.
If it's a device using two 18650 batteries and will run on one, or the other, then the batteries are running in parallel. i have some lamps like that. If both are in, then it flattens them both together, but they last twice as long. Best to use them or have them installed at the same time so that they will always be in the same state of charge.
Well I did, but after an hour with the torch on, one battery showed full and the other empty. I thought maybe it was nowhere near empty, and that the charger would quickly show a much higher reading. After about half an hour it was only showing 280 mAh out of 2000 written on the battery. Then I forgot for a bit and when I looked again it was showing full, and I noticed that it was flashing a number in between, which was 400 or so, so these batteries I think are not too good. I'll buy a couple of spares next month.
Odd. It sounds like one of the batteries is faulty, though those battery capacity meters are not always too accurate.
Maybe try switching the two batteries around to see if the same one goes flat first? And check the contacts are good and clean.
We don't see many devices using 18650's, though some vapes use them? Let us know if you get a good price/capacity. Take stated capacity with a big pinch of salt
Beware Chinese 18650s. Also beware any that state capacity over 3500mAh.
One really good test for the better battery is to weigh it. >44g for the better ones: <40g for the rubbish.
The radio uses two and my hand torch uses one. Sourcing the batteries is a nightmare of contradictory and confusing info. I'll stick to Panasonic, Sanyo, Samsung, LG, Molicel, Epoch, from a distributor that looks authentic. They are expensive, around the £7-10 mark. There flat top and button top, protected, not protected, not protected markd as protected, tab top. Often the same item number has a button and flat version.
Mine are deffo button and I assume protected is best.
I'll probably get one of these https://www.ampsplus.co.uk/sanyo-18650- ... -protected https://www.nubattery.co.uk/lg-mj1---18 ... button-top
This is how I bought my 18650s. https://www.amazon.co.uk/Lambony-Rechar ... B081NCKBGD
I got 2 x 1800mAh batteries + 1 Good COB lantern for £11 ( I paid £20 for two lamps )
The lantern includes all the electronics to make it a useful power bank. If can be charged from USB or it can charge other USB devices. Though 1800 isn't the highest capacity available, it's not a bad size and you get the lamp virtually free.
Lamp will also work with 6x AA cells, which it can also use the charge features on.
I understand that some power tools use 18650s, so if you can find some cheap ones...
Graceful Degradation! Prepping's objective summed up in two words. Turning Disaster into Mild Inconvenience by the power of fore-thought
jennyjj01 wrote: ↑Tue Nov 22, 2022 4:04 pm
This is how I bought my 18650s. https://www.amazon.co.uk/Lambony-Rechar ... B081NCKBGD
I got 2 x 1800mAh batteries + 1 Good COB lantern for £11 ( I paid £20 for two lamps )
The lantern includes all the electronics to make it a useful power bank. If can be charged from USB or it can charge other USB devices. Though 1800 isn't the highest capacity available, it's not a bad size and you get the lamp virtually free.
Lamp will also work with 6x AA cells, which it can also use the charge features on.
I understand that some power tools use 18650s, so if you can find some cheap ones...
Did cross my mind just to buy another torch or whatever with batteries included, but I think I want to fork out for branded batteries this time. I have plenty of power banks (two big ones, plus the radio acts as one).
Either the cell is not making contact while the pair are discharging, or it's a faulty cell.
I didn't Google reviews for your charger but Xtar seem to be fairly trustworthy brand, so I'm assuming not a faulty charger.
Definitely get cells from reputable suppliers, the ones bundled with tat on eBay/Amazon are an absolute gamble.
I've had success with cells from 18650.uk or fogstar, they used to do email promotions every now and again, I've not been keeping an eye on my junk email account recently though.
Also might be able to find a discount through vape/torch forums, if you search the web.
I don't know what electronics are on your torch or radio, I'd err on side of caution and get protected cells. Downsides: more expensive than bare cells and if you run them low, the protection will kick in and your torch will not turn on until you charge the cell again.
Edit to add: a easy test is to fully charge both cells, measure the voltage straight off the charger, then again the next day, and a couple of days later then maybe a week later. The voltage shouldn't fall much if the cell is good, and will fall if its bad. The DIY powerwall, vaping and flashlight forums are good resources for this kind of stuff.
tarmactatt wrote: ↑Tue Nov 22, 2022 8:52 pm
Either the cell is not making contact while the pair are discharging, or it's a faulty cell.
I didn't Google reviews for your charger but Xtar seem to be fairly trustworthy brand, so I'm assuming not a faulty charger.
Definitely get cells from reputable suppliers, the ones bundled with tat on eBay/Amazon are an absolute gamble.
I've had success with cells from 18650.uk or fogstar, they used to do email promotions every now and again, I've not been keeping an eye on my junk email account recently though.
Also might be able to find a discount through vape/torch forums, if you search the web.
I don't know what electronics are on your torch or radio, I'd err on side of caution and get protected cells. Downsides: more expensive than bare cells and if you run them low, the protection will kick in and your torch will not turn on until you charge the cell again.
Edit to add: a easy test is to fully charge both cells, measure the voltage straight off the charger, then again the next day, and a couple of days later then maybe a week later. The voltage shouldn't fall much if the cell is good, and will fall if its bad. The DIY powerwall, vaping and flashlight forums are good resources for this kind of stuff.
Thanks, will try that. I just them back in the charger. Voltage was 4.2 for both, but the charger read 0 capacity and started charging them. Obviously it can't tell how charged they are or the capacity. It only got up to about 180mAh and they were full. Obviously the 180 is what the charger has put into them. The other day it was over 400. So I can only tell the capacity if I fully discharge them, which you're not supposed to do. They do sell a charger that charges, discharges, then charges, to tell you the true capacity. But it's too expensive for my purposes. At least I know the reading is what it's put in, not the actual capacity. So these batteries are probably ok. But I'll get some decent spares next month.
