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694 votes
Accepted

Why is there so much fear surrounding LiPo batteries?

Every cell phone (as well as laptop and nearly everything with a rechargeable battery) uses LiIon/LiPo (essentially equivalent for the purposes of this discussion). And you're right: In terms of ...
metacollin's user avatar
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87 votes

Why is there so much fear surrounding LiPo batteries?

To use Lipo batteries safely, you must treat them with the same respect you would anything that can store and rapidly release a large amount of chemical and/or electrical energy. The bigger the ...
Brian G's user avatar
  • 971
57 votes

Why is there so much fear surrounding LiPo batteries?

When a big company wants to make a LiPo charger, they can: A. Have experts on staff and do extensive testing to make sure the charger will work safely across the full range of operating conditions. ...
Adam Haun's user avatar
  • 22k
43 votes

Why is there so much fear surrounding LiPo batteries?

[Though this late answer may get little exposure now that the question has exited the hot-list, I think it is essential to further emphasize the contrast between the comprehensive safety features in ...
Bill Dubuque's user avatar
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15 votes
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Why do drones use Li-Po instead of Li-Ion?

For this answer I'm going to define LiPo as flat packs, and Li-Ions as 18650s. The reality is more messy than that, but I believe this way of defining the terms will help answer your question as you ...
Dampmaskin's user avatar
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14 votes
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How much can I overcharge a 4.35V LiPo?

The charge (termination) voltage level of Li-ion batteries is specified by manufacturer. The specification is based on reasonably accepted number of cycles ("battery service life") a battery can ...
Ale..chenski's user avatar
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14 votes
Accepted

Is this MOSFET upside down?

It is correct. You normally see PMOS connected like this to act as a reverse-polarity "diode". simulate this circuit – Schematic created using CircuitLab It has much less voltage drop ...
DKNguyen's user avatar
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13 votes

Calculate battery percentage on LiPo battery?

According to some empirical values I found on the *net, this seems to be a quite accurate estimation of remaining energy (in percent) of a typical lipo (rated 3.7V, fully charged at 4.2V): $$123 - {...
Roho's user avatar
  • 131
12 votes

How much can I overcharge a 4.35V LiPo?

Charging Li-Poly and Li-Ion is not as simple as just pumping a voltage across it. It's a two-stage operation involving both constant current and constant voltage. Apply a constant current of (say) 1C ...
Majenko's user avatar
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12 votes
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Power bank or fire hazard?

Those are a fire hazard. Even if someone can sell something, it does not mean it should be sold. I recall seeing a picture of similar device that had melted itself. What likely happened was bad ...
Justme's user avatar
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11 votes

How do/can I charge a Li-po battery without a fancy charger (just using a current)?

You need a proper charger to charge Li-po batteries safely, using the right algorithm; "just using a current" won't do and could damage the batteries. For your purpose, you need a solar ...
ocrdu's user avatar
  • 9,260
11 votes

Why is charging with Lithium batteries with a small load dangerous?

If your charger outputs 1 A in CC mode, and has a 500 mA constant current load connected, then 500 mA goes to battery and 500 mA to the load. So the battery will also charge slower because only half ...
Justme's user avatar
  • 152k
9 votes

Understanding LiPo charging / protection circuit

Protection circuits are usually distinct from charging circuits. Many battery packs are designed with the intention of being charged by a dedicated unit that will control the charging process. The ...
John Evans's user avatar
8 votes

Why is there so much fear surrounding LiPo batteries?

I think your info is outdated. I had a coworker who was into RC airplanes. They were early adopters of LiIon technology because they are light and hold a lot of power. He related how they had two ...
JDługosz's user avatar
  • 695
8 votes

why do laptops have 10 or 20 volt batteries if most components only use logic level voltages

Because while total power stays the same, voltage droop across a cable due to high currents can be avoided with higher voltages and lower current. Copper is expensive, and it's simpler to deal with 2....
Passerby's user avatar
  • 73.1k
8 votes

How do/can I charge a Li-po battery without a fancy charger (just using a current)?

If you can keep the voltage of each cell individually to less than or equal 4.1V (4.0V safer still) then you can charge with current from solar panels. If solar panel max current into battery is never ...
Russell McMahon's user avatar
  • 151k
8 votes

Why is charging with Lithium batteries with a small load dangerous?

Basically you want to charge the battery until the end of charge condition is reached (voltage >= Vthreshold and current <= Ithreshold) and then end the charge and let the battery rest. The end ...
bobflux's user avatar
  • 78.4k
8 votes

How is the output of an MPPT solar charge controller connected to a battery?

MPPT is a technique. "An MPPT" is a somewhat meaningless term unless it's in the context of some load that can take varying power gracefully (i.e., the system is a battery charger, a grid-...
TimWescott's user avatar
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7 votes

Why is there so much fear surrounding LiPo batteries?

All great answers. Here is a short one. A 7.4 volt. 5 amp-hour battery has 37 watt-hours of energy, or 133,200 joules. Compare to a .357 Magnum's 873 joules of muzzle energy. The trick is not to ...
John Birckhead's user avatar
7 votes
Accepted

Is it safe to charge a Li-Po battery at a lesser C rate than its usual routine?

You can always charge a Li-ion or Li-Po battery at less than its specified rate provided that all the normal charging requirements (CC followed by CV, don't overcharge, don't trickle-charge, don't let ...
Ignacio Vazquez-Abrams's user avatar
7 votes

DC-DC Boost converter in Parallel

In your post you said that you wanted 1A out at 12V, and that you calculated that you needed 3.24A in with no losses. You didn't state what input voltage you were using, but it can be calculated. ...
user4574's user avatar
  • 12.3k
7 votes

why do laptops have 10 or 20 volt batteries if most components only use logic level voltages

Ohm's Power Law: $$ P = V*I = I^2 * R $$ Power lost in copper, and needing to be dissipated as heat, goes up with the square of the current. Consumers don't like thick cables or hot laps. So ...
Anthony May's user avatar
  • 4,194
7 votes

Are lithium ion batteries damaged by strong magnets?

It should not have an affect on the battery, the magnetic field my deviate the path of ions and electrons slightly but not have any effects on the battery itself. If the magnets 'slam' into the ...
Voltage Spike's user avatar
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7 votes
Accepted

Block battery if USB is plugged in

With the drain and the source connected as you show, it will do what you want — the body diode is pointed in the correct direction, as shown below. But you do need a diode in the USB path, so that the ...
Dave Tweed's user avatar
  • 174k
7 votes

How do/can I charge a Li-po battery without a fancy charger (just using a current)?

With lithiums you need a battery management system. No other choice. If you don't want a BMS, use nickel metal hydride. A BMS is a Battery Management System - it protects the battery from conditions ...
Harper - Reinstate Monica's user avatar
7 votes

How is the output of an MPPT solar charge controller connected to a battery?

The MPPT charge controller you describe actually is a DC-DC converter (a buck converter). The input to the controller is the solar panel voltage. The output is the battery voltage. Conceptually, all ...
user57037's user avatar
  • 29.4k
6 votes
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How does a battery balance and protection circuit work?

I've read a chapter from a very good book which answers it all. I highly recommend reading that chapter or the book but if you want the very short story things are like this. Normally it is assumed ...
Bogdan's user avatar
  • 622
6 votes

Controlling a DC Motor 48v with a 63v power supply

You actually have a few issues when driving a DC motor with more than the boilerplate voltage rating. Max Current: At no time should you exceed the maximum current rating of the motor. It will ...
Trevor_G's user avatar
  • 46.7k
6 votes
Accepted

Why don't some 2S LiPo packs include a balancing connector?

If a lithium-ion battery with more than one cell has no provision for balancing, it's a blatant safety risk. As a battery ages, one cell will drop in capacity faster than the other, causing the lower ...
jms's user avatar
  • 8,651

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