Ad ID: 1520
Added: 28 September 2021
Condition: Brand New
Modern society is powered by various electronic devices such
as cell phones, laptops, and cameras. All of these things use batteries. There
are many battery types out there, and each type has its strengths and
weaknesses. For this article, we will discuss and compare NiMH and Li-ion
These types of batteries are usually used for high-drain
devices like laptops, cellphones, iPods, and digital cameras. However, they
have some distinguishing features which make one type more efficient than the
other in some regards.
High Energy Density: These have an average of 2200mAh (milliampere
hours—the amount of current in
milliamperes that it can give multiplied by the time in hours). This is greater
than the 1500mAh seen in Li-ion batteries. These are the standard numbers in
1.2v NiMHs and 3.7v Li-ions.
Compatible: If you have ten gadgets using an NiMH
battery, you can use a single pack to power them all—not simultaneously, of course. NiMH uses
standard sizes so they are compatible with all devices using sizes such as AAA
or AA. Compared to Li-ions, the sizes depend on the manufacturer or model of
the device. I did see some AA size Li-ions around the market, so it may be
worth checking them out.
Safe: They have less active materials compared
to Li-ion batteries. NiMH can pop if they are overcharged too much or short
circuit, but this is nothing compared to a Li-ion, which can potentially blow
Fully Dischargeable: By this, I mean these batteries can be
brought down to 0 charge, if you can get them to reach that. They will still
charge; just don’t let them suffer from reverse polarity, or else they will be
High Self-Discharge Rate: NiMH lose a large percentage of their
charge every month. The number is around 5% in the first week after the charge
and about 50% in the first month. There are low self-discharge (LSD) rate types
available. They are more reliable than the standard NiMH, but they have lower
capacities, usually around 2000mAh.
Unreliable for Low-Load Devices: You should not use NiMH batteries for
devices such as clocks. They will lose charge faster through self-discharge
rather than the load. Use alkaline, Li-ion, or lithium batteries instead.
Low Voltage Output: Each AA cell can only give 1.2v, compared
to Li-ion cells that can give 3.7v.
Long Charging Time: The standard charge time of a NiMH is 10–12 hours. Fast charging these cells can
result in damage. Li-ion cells can be charged at around 1–3 hours, depending on capacity.
Sensitive to Extreme Temperatures: At extreme temperatures, NiMH voltage
output will drop. Li-ion batteries can tolerate these temperatures to some
Reliable: These have a significantly lower
self-discharge rate than a NiMH battery. As a result, they can be used for low-current
devices like clocks or watches.
Small: They are smaller and lighter compared to
Higher Voltage Output: A single cell can deliver 3.7v while even
two NiMH cells can only give 2.4v.
Faster Recharge: Li-ions can be charged in about 1–3 hours, depending on capacity. This is
much faster than the 10–12 hours needed for NiMH
Temperature Tolerant: These can better withstand low
temperatures and warmer environments compared to NiMH cells.
Higher Energy Density: This means that the battery carries more
charge per gram than a NiMH battery.
Lower Capacity: These have an average of 1500mAh compared to
the 2200 mAH average of NiMH cells.
Incompatible: Different manufacturers make different sizes
and shapes for Li-ion batteries, making them usable only to a specific set of
devices. NiMHs have standard sizes.
Less Safe: Ions are a very active material. They can
react easily and generate a lot of heat. That’s why there are circuits in those cells. They are used to check for
voltage and temperature. In other words, the circuits prevent the cells from
Not Fully Dischargeable: If a Li-ion battery gets fully discharged, it
will be damaged. Yes, you can shock charge it, but its efficiency will
decrease. Always keep this kind of battery charged above 50%.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes
only and does not substitute for personal counsel or professional advice in
business, financial, legal, or technical matters.
Nikola Tesla on August 24, 2020:
I go defenitely with nimh!
Eibdelov on February 27, 2020:
Latest nimh batteries are capable of high speed charging as
am using in latest fast charging trimmers of philips
Fukyosnatch on January 23, 2020:
This article is so poorly written I already don’t trust your
factual claims on the topic at all, let alone this specific issue. I’m not
saying you’re wrong, but this entire piece was so poorly written, i might as
well not have even read what you had to say about it.
Ahmed on March 25, 2019:
NiMH is better than Li-ion
Matthew on March 07, 2019:
So much wrong with this article that I don’t know where to
Well, to begin with – energy density is current x time x
voltage. You are missing the voltage part. Li-ion batteries actually have much
higher energy density.
If you said “higher charge density” you would be
right, but no one actually cares about that. It’s energy density that’s
Ecospider5 on December 16, 2018:
Low self discharge NIMH are way better than you state. They
hold over 80% charge for 3+ years.
Raffles on November 23, 2018:
@Enricoludo to power your 12V 2.6A fan for up to 8 hours, you
need a at least a 21Ah 12V battery, however that would run it completely flat,
so you probably want to get something a bit bigger than a 21Ah battery. Really
you are looking at a lead acid leisure battery for this, rather than either
NiMh or LI-ion. If you do want to use NiMh batteries you will need to put 10 in
series to get to 12V. A standard NiMh AA battery is typically around 2 Ah
capacity, so you will need around 12 in parallel, to get 24 Ah capacity. 12 x
10 = 120 NiMh AA batteries to power your 12V 2.6A fan for 8 hours. That will
cost a lot more than a standard 12V leisure battery, and when they are flat,
you will have 120 NiMh AA batteries to recharge before you can use the fan
again. Alternatively looking at Li-ion batteries, put 3 in series to get 11.1V
which is close enough to 12V to power a fan. A standard Li-ion 18650 battery is
typically 2.5Ah capacity so you will need 10 in parallel to get 25 Ah. 10 x 3 =
30 Li-ion 18650 batteries. Not as bad for recharging as the AA batteries, but
still a big job. I have a third suggestion. Get a solar panel. I assume you
only want the fan running when it is hot and sunny, which is perfect for
gaining solar power. The batteries then only need to have enough capacity for
when the light fades and the panel isn’t giving you enough power to run the fan
by itself. Your fan draws 31 W of power. You need a solar panel that is rated
at least double that power as solar panels rarely produce the power they’re
rated at (only when the sun light is hitting them at exactly 90°). So I would recommend you get say a 75W solar panel and a small
12V leisure battery (say 7Ah). I’ve got a set up like this in my home, although
I use it for phone charging rather than powering a fan. I hope this helps.
Tom Jones on March 01, 2018:
Nonsense about ions in lithium batteries and circuits
preventing blowing up. Utter rubbish. The circuits protect the batteries from
discharging too low and preventing reverse charge. All batteries have a
potential to blow up if they are fully charged and a short occurs, even ones
with the protection circuits.
Really this article should be completely removed. It is
riddled with all sorts of misinformation.
Darren Perkins on April 27, 2017:
Doesn’t look like the article was updated at all…now I
don’t know what to believe. Just delete the article for the sake of not
confusing people who want to know the facts. Article is completely useless.
Enricoludo on April 18, 2017:
Hi, I want to power a 12v 2.6A fan when camping, I would like
to keep running it for 6-8 hrs. Minimum, what options do you suggest is best
for this purpose. Thank you for your expertise!
smolny on March 23, 2016:
Others claim that Ni-MH are more tolerant to charge/discharge
at lower/higher temperatures than Li-Ion (and esp. Li-Poly). Would you be so
kind and double-check your sources about it?
John R Wilsdon from Superior, Arizona USA on February 06, 2016:
As a person frustrated in the past with how to make a
decision about batteries, this hub was very helpful and well designed. I will
refer to it in the future before a purchase. Thank you.
leakeem (author) from Earth on May 04, 2015:
Sirs, article has been updated.
Radmila on December 12, 2014:
Well put, sir, well put. I’ll cerltinay make note of that.
Trevor on July 10, 2014:
10 months have gone by since this very significant comment
that I almost didn’t read. Can you update this article for the sake of correct
leakeem (author) from Earth on September 12, 2013:
Thanks for the update/info! Will update that soon.
Michael Cline on September 12, 2013:
Be advised the energy density is actually much higher for
Li-ion versus NiMH. Energy density is measured in Watt Hours/weight, not
mAh/weight. Also, NiMH can be recharged much faster than Li-ion currently. You
can list an additional Con for NiMH that it requires a much more complex charging
algorithm. You can remove the self-discharge Con form NiMH since the new type
cells do not have this problem anymore.
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