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2 votes
Accepted

Strange resistor in battery charger

There seems to be 2 Ohm resistor (30Y) connected in series with capacitor between battery terminals. The purpose of the resistor is clearly explained in the datasheet: For some LDO designs, since ...
Rohat Kılıç's user avatar
0 votes

Lithium iron phosphate battery charging for single and multiple 12V 7Ah batteries

The power available limits the charge current/rate possible, trying to keep charge current/rate possible with one battery, the power supply will be overloaded. Charging one 7.2 Ah battery to 14.6 V ...
greybeard's user avatar
  • 1,798
0 votes

Bipolar 2s1p Li-ion array BMS and charging

I bet you $ 1 that the reason you want a +/- 2.5 V supply is because you have a sensor that produces a bipolar signal and you need to feed it into an AD converter. If so, you don't need a 2.5 V supply....
Davide Andrea's user avatar
0 votes
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Bipolar 2s1p Li-ion array BMS and charging

What you have there is not a single battery with two 18650 cells. Instead, what you have is two batteries, each battery having a single cell. Therefore, you will need to treat them as two separate ...
Davide Andrea's user avatar
1 vote

Is it okay to raise the output voltage of a 5v charger to charge a laptop battery whose charger supplied 15v (with a step up module)

You are forgetting to calculate power. 15 V × 4 A = 60 W 5 V × 2 A = 10 W You would be way short of power before you consider the losses of your voltage step-up converter. Remember that when you ...
Transistor's user avatar
  • 176k
2 votes

Is it okay to raise the output voltage of a 5v charger to charge a laptop battery whose charger supplied 15v (with a step up module)

No, it is not OK. You are forgetting that the 15V power supply is just a power supply. You cannot connect 15V directly to a battery. The battery charger is in the laptop, between the 15V supply and 10....
Justme's user avatar
  • 149k
1 vote

How might one attempt to recover a fully drained NiMH cell?

Some years back I ordered a number of NiMH AA cells from a (generally) reputable supplier. It seems that they had been in store for a while as many of them measured 0V or close to. I found that some ...
Frog's user avatar
  • 7,315
1 vote

How might one attempt to recover a fully drained NiMH cell?

You can try to revive the batteries with a standard bench supply that has settable output voltage and current limit. People usually try to revive discharged cells by shorting them with wires to a good ...
Justme's user avatar
  • 149k
3 votes

I keep Blowing up my i2C (ISO1540) isolator when plugging and unplugging my battery

So taking into account all the comments, we went and re designed the i2C protection. Assuming that we were having issues with the ISO1540 IC due to ESD in the I2C bus lines. We increased the ...
Pepe's user avatar
  • 53
6 votes
Accepted

How to remove huge startup current spikes in charger circuit?

You will always get surges when you connect a capacitor to anything at a different voltage. The duration of the power spike is about 2uS and as such will not effect anything. The energy transferred is ...
RoyC's user avatar
  • 10.1k
0 votes

How to monitor voltage and charge status in USB battery pack

I use a 9v rechargeable battery through a circuit that delivers 5v wired to a usb plug. I have a voltage divider connected to the battery and tap off a voltage that is safe for my arduino to measure ...
Gordon's user avatar
  • 1
1 vote
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Charger Output and Device Compatibility: A Safety Concern

and the charger has a 5V 2.5A, 9V 2A, and 12V 1.5A output. Sounds like a smart/quick charger that is able to "talk" to the target device and adjust the output accordingly. My answer will be ...
Rohat Kılıç's user avatar
1 vote

Charge batteries in parallel, discharge in series

Yes, it's possible, but fraught with a few problems: Balancing is trickier While in series, one of the two batteries will be the first to be emptied; when its BMS shuts it down, the load will be ...
Davide Andrea's user avatar
0 votes

Vax Blade 4 BMS board issue (5 x 21700 cells Li-ion 18v battery)

a defective / blown component on the board which has oozed out its stuff Gosh no. There is no "stuff" inside those electronic components to ooze out. That's just flux from the soldering ...
Davide Andrea's user avatar
1 vote

Will this Ebike powerbank circuit work?

It looks OK. Generally, there's not need for that ideal diode because generally the charger doesn't discharge the battery while off. The SoC meter based on bus voltage won't really tell you much ...
Davide Andrea's user avatar
0 votes

TP5100 battery charging IC PCB design burning out

In your schematic you show CS (pin 13) connected to VREG. This places the IC in a 2 cell (8.4V) mode. For single cells CS should be left open circuit. It is not certain that this, rather than or as ...
Russell McMahon's user avatar
  • 150k

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