# Is a Li-Polymer battery of strength 4200 mAh equal to Li-Ion 4200 mAh battery?

DrSunil Vaswani May 8, 2013

Is a Li-Polymer battery of strength 4200 mAh equal to Li-Ion 4200 mAh battery?

1. Rob H
May 20, 2013 at 10:19 am

Different types of battery produce different voltages. A standard AA cell is 1.5volt but a rechargeable AA is often only 1.2 or 1.3v. That's why some equipment doesn't work well on rechargeable AA batteries.

Power is Volts times Amps so a 2000mA standard AA cell holds more power than a 2000mA rechargeable
Also a battery may be multi-cell.
My digital camera claims to provide 3.6v (3x1.2v cells) at 900mAh so has a power capacity of 3.2Wh
If I had a camera with a 2.4v battery (2x1.2v cells) and rated at 900mAh capacity it's power would be 2.2Wh

The differences are likely to be quite small for batteries in modern digital devices but strictly it's better to think of power in Watts not Amps.

Just to be clear a 2000mAh is the same as 2Ah and it means it is (theoretically) capable of providing a current of 2Amps for 1 hour or 0.5 Amps for 4 hours.
Similarly 2Wh can provide power of 2 Watts for an hour or 0.1 Watts for 20 hours.

• DrSunil Vaswani
May 24, 2013 at 5:30 pm

Thanks for the minor clarification which has helped clear so much details not understood

2. null
May 10, 2013 at 10:47 am

The components that use the most power in a phone/tab are the processor and screen, followed by WiFi, but the details vary from model to model and the best way to compare is to see the manufacturer's stated "talk time" or equivalent or, if the manufacturer provides it, the typical and peak drain figures.
For convenience, think of 4200 mAh as a quantity, say, of water, and the drain as the rate at which it "pours out" (say 500 mA hour). In the example above the battery will last for a little over 8 hrs (4200/500). If the drain figure is sufficiently lower, than a smaller capacity will suffice to provide the same battery life (for example, if the drain is 200mA, then a battery of 1700 mAh will last about the same time).
In short, the only realistic way to estimate the battery life for a particular phone/tablet is to accept the manufacturer's claims or to do real-life, side-by-side tests. Generalisations simply don't work in this field.

• DrSunil Vaswani
May 24, 2013 at 5:32 pm

Yes only actual use can tell. Maybe other factors of the device also affect same power ( 4200 mAAH ) battery usage in multiple devices. Am I correct?

3. ha14
May 9, 2013 at 5:56 pm

i think both will do the same job,the pro and con can be checked here
http://batteryuniversity.com/learn/article/is_lithium_ion_the_ideal_battery
Charge and discharge characteristics of Li-polymer are identical to other Li-ion systems and do not require a special charger. Li-polymer can be made very slim to resemble a credit card. So as advantage your mobile phone can be thinner.

• DrSunil Vaswani
May 24, 2013 at 5:32 pm

I understand

4. Md Mukhtar Mohsin
May 9, 2013 at 12:35 pm

As Oron Joffe said it does not matter which type of battery is it, same power rated battery will drain at same rate,to get more detailed info check the links.

http://en.wikipedia.org/wiki/Lithium-ion_battery

http://en.wikipedia.org/wiki/Lithium-ion_polymer_battery

5. Oron Joffe
May 9, 2013 at 9:53 am

As Rob H says, 4200 mAh _is_ the battery's "strength". ANY battery with a capacity of 4200 mAh has the same power in the sense that it can drive a device of a given power rating for the same amount of time. The difference between the batteries is in their characteristics - weight, recharge "memory", number of recharge cycles, environmental factors etc. To sum up, the batteries are not the same, but they will drain at the same rate.

• DrSunil Vaswani
May 10, 2013 at 4:53 am

I understand

Thanks!

Appending a subquestion : Would a 4200 Li-Po battery in a 7 inch tab be used equally as a 2000 maaH battery in a 5 inch phone ( Both android ) ?

• DrSunil Vaswani
May 24, 2013 at 5:33 pm

Is the answer below to subquestion answered by you? as user name is different

• null
May 25, 2013 at 10:50 am

No, I am Oron, and have only written one answer in this thread.

6. Rob H
May 9, 2013 at 9:00 am

What do you mean by "equal strength"?

4200mAh is the capacity of the battery so they are nominally identical in that respect. It means that (depending on the technology) the battery can provide a current of 4200mA for one hour or 420mA for 10 hours.

Different battery technologies have different characteristics, some are a good choice if you need a high current (for a short time), others can't provide a high current but are better suited to providing a low current for a long time. Most rechargeables go flat quickly even when not in use but some can retain the charge for a long time.

The voltage differs with technologies too - a disposable AA battery might provide 1.5 volts but most rechargeables are more like 1.3 volts. In some applications that means rechargeables don't work or give poor performance.

Selecting the right battery for a specific task can become quite a technical challenge which is why retail battery packaging sometimes lists the kind of device they are best suited for. An example of the problems with selecting the best battery technology for a specific task might be the new Boeing Dreamliner. The entire fleet was grounded for several weeks because of a battery catching fire.

• DrSunil Vaswani
May 11, 2013 at 4:40 am

hullo

By equal strength I meant that storing equal power on recharging and draining at equal rates?

Appending subquestions :
Does a 2000 maaH battery store and drain power equally to a 2000 Li-Po battery?

Does a 7 inch tablet require double ( 4000 ) battery than a 5 inch phone ( 2000 ) ?

Why are Li-Po batteries used in some devices while maaH batteries are seen in phones?

May 9, 2013 at 7:21 am

• DrSunil Vaswani
May 11, 2013 at 3:59 am

Thanks!

I shall check

Pl clarify - 2000 maaH and 2000 Li-Po are equal in power storage and drainage?

8. DalSan M
May 9, 2013 at 5:25 am

Lithium-polymer batteries tend to hold a charge better and longer, but at a higher cost. The charging cycles are greater than with lithium-ion, meaning the "wear" on lithium-polymer is less; after a couple of years of use, the drop in battery use time is minimal so the battery life is near the same amount as new. There are conflicting stories about this, though. This may because of using lithium-ion-polymer hybrid batteries instead since it is safer, cheaper, lighter, and can be shaped differently than lithium-ion batteries; they aren't as flexible or thin as true lithium-polymer batteries, though. Lithium-polymer batteries are known as explosive batteries since some of the iPhones and other devices that use these types of batteries have caught fire, and almost explosively igniting without warning. As long as proper care of any battery is given, neither battery type is really that much safer than another (HTC HD2's have had similar ignition problems, and they had lithium-ion batteries).

• DrSunil Vaswani
May 11, 2013 at 3:57 am

What is difference between maaH and Li-Po batteries ( which are seen in phone and tab specs ) ?

You mentioned that Li-Po batteries hold power longer. You mean compared to Li-Po maaH battery would drain quicker?

Pl clarify - 2000 maaH and 2000 Li-Po are equal in power storage?

• DalSan M
May 12, 2013 at 7:52 am

Li-Poly and Li-Ion with the same amount of mAh are equal in power storage capacity, meaning 2000mAh for both are the same, and the voltage are the same (3.7 volts per cell). The difference between Li-Poly over Li-Ion is the fact Li-Poly has a slightly higher amount of energy density, and the materials used allowing it to be shaped differently than Li-Poly.

As far as holding power longer, I meant that the life span (though not exactly proven, only have read that many people experience this) is longer to where the battery wear is more resistant. Instead of having a life span of up to 2 years with Li-Ion before the battery discharge becomes very quick when used, many people have said that Li-Poly batteries holds the charge longer after 1 or more years when used.

More information can be found here: http://www.allaboutsymbian.com/features/item/15775_How_do_Lithium_batteries_work.php, in which a chart shows that there are different chemicals and metals used when making lithium ion or polymer batteries. In order for lithium polymer batteries to be interchangeable with lithium in batteries, the creation of hybrid polymer batteries were made. True lithium polymer batteries are dry-cell, which is more dangerous and needed higher voltage and heat to catalyze to produce power. The polymer batteries used in devices today use an electrolytic gel that reduces the energy barrier, making it safer and more compatible with ion batteries. The energy differences are not that big, so in all actuality most users may not notice much of a difference between the batteries. The main people that would say there is a big difference are radio controlled airplane and helicopter hobbyists, where lighter weight is necessary. Lithium-polymer batteries are recommended here, but the hobbyists also will tell you that if the plane crashes, you must replace the battery. This is because the battery gets damaged easier, even if there are no signs of damage, and the battery most likely would explode or ignite on its own eventually. Sometimes the first charge after becoming damaged, or after a few charge cycles.

• DrSunil Vaswani
May 24, 2013 at 5:36 pm

But answer below by another respondent suggests that same power any type battery drains equally

9. Rajaa Chowdhury
May 9, 2013 at 3:17 am

I guess the strength and the output should logically be the same. I guess the difference is in the weight of the batteries. However, I am not 100% sure, others may be able to give a better advice.