Discharge creates a bunch of heat. Feel the bottom about half way through a discharge with all 4 slots filled.
oh good point, damn! i see the 2 outer ones are 63c, inner ones are like 56c. thats pretty hot
I have an Opus. It has a fan. The fan whines and lots of people hate it. But, it does help cool the system so it can discharge more banks at a higher rate. Even so I have an 80mm PC fan pointed at it during higher work levels. Small USB powered fans or laptop coolers can work well too.
i have a spare case fan…but thats gonna be hard to set it up lol…
how hot is too hot that i need to do something about it? whats a safe temp threshold?
Easy to set up if you have some 6-12v power bricks from another device. That’s what I did.
In fact, a 120mm PC case fan is cooling my fridge compressor coils powered by a 12v wall wart. Fan died and a replacement was $350 for a tiny damn FAN! PC fan works fine. cost me $12.
Anything over quite warm is hard on batteries. Too hot to hold, it simply too hot.
All batteries last longer if kept cool. They may perform better when warm > hot via increased chemical reaction, but that is ultimately at the expense of longevity.
what do you have it connected to? dont you need to buy a separate adaptor of some sort?
Power bricks/wall warts > those little black power adapters for various devices, like the one powering your charger.
Some people just have them around in a box from old devices that have been tossed. If you don’t, small USB powered personal cooling fans are pretty cheap.
Fans pull very little amperage. You just need a ‘brick’ from 6v-12v. PC fans are 12v. They will run from 6v>12v; slower, quieter, but with less air movement at 6v.
Cut the plug adapter barrel off the brick, cut the fan wire plug off, and wire red>red, black>black. Other wires can be ignored as for PC fans they are speed control info for the motherboard.
Note - if you have a PC recycle shop around they often have boxes of them for cheap. I’ve gotten replacement power supplies (upgrades) for chargers from a recycle shop. I bring the charger body in to make sure the plug fits, make sure the voltage is right, and the amperage is more than specified. The device will only use the amperage required. My Opus came with a 12v/2A power brick, which is NOT GOOD ENOUGH. It now runs on 12v/3A and runs fine with a new adapter.
i was talking about cable adaptor cuz pc case fans use those 3 pin 4 pin headers, but i guess that answers my question lol
I have my Opus sitting on top of a PC fan and is powered by a PC power supply. Easy enough to wire the power supply to supply 12v, 5v, and 3.3v. Both were salvaged from a desktop that I was getting rid of.
There are two heatsinks for the outer slots:
oh wow you took it apart…nice…but i guess the question is, is it just because lack of real estate that they didnt install heatsinks for the inner 2 slots?
I’m not sure why they designed it with only 2 heatsinks.
The display is in the way:
Compared to the surface area of the battery, those heat sinks are not terribly significant. They are helping cool a small part of the battery and charger.
Notice the slider connection mechanism. All those multiple contact surfaces is one of the factors that makes the internal resistance not so accurate.
I haven’t been inside that charger, but it’s often just a matter of 2-4 screws and it comes right apart. Once over the initial trauma it’s not too bad. Gotta start somewhere.
I’m not recommending it, especially since it’s a new unit for you. Just pointing that out.
I opened my S4+ up to desolder the piezo speaker:
- remove rubber pads from the back
- remove screws from rear cover
- remove rear cover
- unclip the springs
- slide the main PCB out while being careful not to damage the display cable (the heatsinks make this a tight fit)
- unscrew the display PCB
- carefully lift the display PCB up and unclip the display cable socket and remove the cable
- desolder the piezo speaker and remove it
- insert the display cable back into the slot and clip it
- carefully put the display PCB back in and screw it in (this is where everything dropped and I thought I broke the display) :person_facepalming:
- insert the main PCB
- clip the springs back on (tricky! try using tweezers or something to bend the spring so that the loop is easier to latch onto)
- attach rear cover
- insert screws in rear cover
- put rubber pads back on
Disclaimer: I don’t recommend doing this. This could damage the charger.
ya i found that the very first resistance reading isnt always accurate, but the second one usually tends to be accurate, cuz every other time after that, with the same battery, regardless of slot, i get the same ball park resistance
i have a feeling this isnt very true for fake/shitty batteries…i been testing all the batteries in the house, some are literally showing like 38mah after testing, but theres no way thats true cuz i put it in a flashlight, and it works…not as bright as a fully charged proper 18650, but its about 80% brightness, and it doesnt just shut off right away, i had it on for a good 30 seconds. so clearly it has more than 38mah…how do i test the actual capacity? is there a better way?
Many LED lights are not accurate for capacity testing. Most do not have a constant current draw > as the voltage drops the amperage drops. I have lights I can easily put in a crappy Li-on, then let it run all night on high and it’s still on in the morning….not much, but it’s still on. Test the voltage and it will often still be ‘acceptable’, ie more than 2.5v.
Charge the battery(s) in question at a low rate until full. Then discharge at a low rate until the charger stops. You should have your capacity. (Note - Don’t know if that charger simply stops at the end of discharge, or might immediately re-charge).
If you use a current that the battery can’t handle, which can be quite low for poor cells, the voltage will promptly sag and the charger will quit. It is appropriately showing the capacity for THAT amperage.
I have NiMh cells that will not put out 0.5A, but will run for a long time at 0.2A. (Use these for LED night lights.)
When Li-on gets that poor I recycle them. I generally want them to pull at least 1A, and won’t bother if they are below 0.5A.
what, no im using the s4+ for the cap test, and the amp is automatically determined by the charger. it charges it to full, discharges, then charge back up to full again. but the discharge process determines the capacity. thats what happens with a good battery, but shitty batteries seem to glitch it out, so none of the readings is accurate, i literally had a 18650 that spit out resistance numbers from 1 milli ohm to 254 milli ohm, which, i know resistance isnt the most accurate, but with good batteries, its always within a ball park at least.
Isn’t there a switch to set amps to manual? If so, use it.
yes, but what do i do with manual mode to get a proper capacity reading off these shitty batteries?