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Batteries on telephones, laptops etc

Batteries on telephones, laptops etc

Batteries on telephones, laptops etc

Could someone possibly elaborate on the possibility of using very many 'smaller' batteries on telephones, laptops etc, assembled as one package off course, than using one, as they do now. Charging them in parallel they would recharge in a minute then using them appropriately to feed the circuit, like in series for example.

RE: Batteries on telephones, laptops etc

That adds a lot of overhead of weight and volume in a weight and volume constrained application. That's because you really cannot charge batteries in parallel. Moreover, lithium ion batteries are quantized to 3.7V.

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RE: Batteries on telephones, laptops etc

"...than using one, as they do now."

Modern smartphones universally (as far as I've seen) use single Li-ion cells. The actual cell is typically a "prismatic" (pouch) cell in a plastic and foil baggie. Ideally they're encased in a hard plastic shell with friendly contacts so that it can be more easily replaced. As opposed to being firmly glued down as the very first item in the very bottom of the case (requiring removal of everything to get to it).

Laptops most frequently use battery packs built-up from multiple (e.g. 6 or 9 or... YMMV) Li-ion cells, often in the 18650 form factor (nominally 18mm diameter and 65mm long). More modern designs (for example, smaller Netbooks, may have fewer cells and they may be built-into the case, not so easily removable.

"...in parallel they would recharge in a minute..."

Actually, it's quite the opposite. Series is generally better.

For example, if you had a laptop with six cells, and each cell was (for example) 3000 mAh, and you wired them in parallel (thus 18,000 mAh total), and then tried to recharge them (from flat) in "a minute", the current would have to be 18,000 mAh (18 Amp-hour) multiplied by sixty (minute to hour ratio), equals a charging current of just over ONE THOUSAND amps. YIKES!!!!!

Of course, even if you allowed an hour to change them in that parallel arrangement, it would still require 18 amps. Still Yikes!

By putting them in series, the charging current for one hour could be reduced to the same numerical value as the 3000 mAh rating, or 3 amps. And that's why laptop battery packs are usually wired up in series, and require a high voltage (e.g. 20 Vdc) changer with several amps (e.g. 4A) current capability.

Modern battery pack systems may include sophisticated cell management technology to ensure that the individual cells, connected in series, are kept balanced (same voltage per cell). That's increasingly common for flying drones and the like. It's probably true that such flying drones have some of the most* sophisticated battery pack technology.

*Excepting that electric cars (e.g. Tesla) are presumably 'off the scale' in such technology.

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