1792 réponses à ce sujet

[garfield2142]

VID_20241202_182444.mp4   965,32 Ko

VID_20241202_182508.mp4   1,03 Mo

VID_20241202_183017.mp4   3,48 Mo

[garfield2142]

One square is 0.5 volts on this setting, so it should be way within spec, yet both mine and @fire_ned 's CakeOnIce constantly complains about low voltage. While measuring with the oscilloscope, it never complained about low voltage, so my teacher is suspecting grounding problems.

[firened]

**Battery chemistry:**
-Li-ion 1s2p from AliExpress are near useless after 3 months (cakeonice).

-li-ion 1s2p from robot-maker or a swiss store last almost 2 years

-Li-ion and li-po don't like being kept charged at 4.2V. alternatives include lower charge voltage (4.0V) or lifepo4.

-lifepo4 can supposedly better handle staying charged. I was not able to find a ups or charge-boost module. So it's not really an option for 1S robots.

[firened]

.

**ups modules:**
However i found some li-ion charge boost ups modules that could be useful for VigiUPS v3.
Let me know if you're interested in testing them together.
https://aliexpress.c...6902029963.html
https://aliexpress.c...7232950866.html
https://aliexpress.c...7647140239.html

[firened]

I just found this on AliExpress:
CHF1.11 | 10pcs/1pc 5V 3A Step Down Buck Power Charge Module TYPE-C USB Lithium LiPo Battery Charger Protection Circuit Board DIY Mobile
https://a.aliexpress.com/_EI9ROVE

I just found this on AliExpress:
CHF2.00 | 22.5W Power Bank Bidirectional Fast Charging Mobile Power Module Circuit Board With Digital/Light Type-C USB Suppor PD/QC3.0 2.0
https://a.aliexpress.com/_ExsRp2u

I just found this on AliExpress:
CHF16.82 | High Efficiency Large Power DC 5V 6V 9V 12V 15V 24V UPS Module IN-OUT 3.7V 4.2V Lithium Battery Charger Discharge Home Network
https://a.aliexpress.com/_Ex2FOUY

[firened]

And some more with 18650 battery holders, which can be easier to source than 1s2p with a correct plug.

[Mike118]

You think it is better to have the ups with 18650 battery holder instead of being able to put the battery where we want ? It is not recommended to put any 18650 in parallel without taking some precautions... letting people play with the 18650 cells directly is riskier than with a protected pack...

[Mike118]

@fire_ned

[garfield2142]

I have 10 pieces of 18650 holders in my basement exactly for this purpose. If my batteries become weak too, I'll replace them with a holder too. However, It takes significantly more space and weight. The minus big wheel type already suffers from too much stress on the n20 motors.

[garfield2142]

Size difference between 2 batteries raw, and 2 18650 holders

[beurre6666398]

Why do you absolutely want a UPS? My big robot uses a specific charger and works very well. My new little robot will also use a specific lifepo4 1s charger.

[beurre6666398]

My big robot have aliexpress li-ion cell, and after 1 years running outside, the battery is still fine. I think buying li-ion on ali is a bit tricky, to many fake.

[Mike118]

The ups is usefull for robot that stay on h24 with a charging station.

[firened]

Fair point, I don't know.

*Edit: especially if people happen to accidentally buy unprotected 18650.

[firened]

Yes i use dedicated cc/cv chargers too on icecream and tooster.

UPS is nice because:
-does not need soldering, often it's laypeople building the robot.
-USB support
-Magnetic charge cable

[xhap0w]

I tried to use those "lite ups", my battery always discharge during charge...

[xhap0w]

And the violet one you should press the power button to turn on the board

[Mike118]

Yes the 600 mA charge for last one is a lame... with such low charge the battery discharge faster than it charge...

[xhap0w]

The first one look like is acting like a BMS, and the discharge curent is not speciffied

[firened]

True. I missed that.