Despite its long-lost popularity, NiMH battery packs still hold a few advantages over LiPos.
NiMH is less prone to catch fire, cheaper price, optimal energy density- the list of reasons is not short at all.
As you’ve landed on this page, we’re sure you’ve your own reason to go for NiMH instead of LiPos for your RC vehicle.
But as with any RC accessories, finding the best NiMH battery is an equally hard nut to crack. On top of that, the voltage diversity, capacity variation, compatibility, and other choices will leave you biting your nail.
In this review, we’ve picked 11 of the best NiMH RC batteries, grouped up as per voltage(7.2V, 4.8V, 8.4V, 9.6V, and 12V). Later on, we’ve discussed some RC NiMH 101, just in case you’re new to it.
Without ado, let’s get it rolling-
Best 7.2v NiMH RC Batteries
Let’s start off the list with 7.2V NiMH RC batteries- the most popular voltage choice. From different capacities(mAh), we’ve picked up 3 of them and broken down the pros and cons. But let’s start with discussing the features that are common in all of them-
What’s Common Among These 7.2V NiMH RC Batteries?
Except for some, most of these 7.2v NiMH packs contain 6 Sub-C type cells. Each Sub-C cell measures about 43mm(L) x 23mm(D), and weighs 74g(2.6oz). Together, 6 of these cells combine to a compact, flat size of the battery pack itself.
The charging rates of these batteries are 0.1C-1C(the slower the better). While discharging, it’s a 10C continuous discharge that they offer. Some of them might offer up to a 20-30C discharge rate as well.
Moving on, you’ll see brands claim ‘No’ memory effect in their NiMH cells. But that’s not 100% true, at least for high voltage(7.2v or higher) cells. Although, it depends more on your way of charging.
In terms of compatibility, these 7.2v cells fit most of the 1/10, ⅛, RC cars(2WD, 4WD), boats, buggies, and trucks. Some of them(Tenergy 7.2V, iMah SC6 7.2V, etc) might go down to 1/12 and 1/16 scale models as well.
Just check the dimensions of both the battery and your battery compartment to get a perfect fit.
Tenergy 7.2V 3000mAh NiMH Battery: More About it
3000mAh is the most desired capacity from NiMH packs. And this 7.2V pack from Tenergy meets the ends of runtime, charging/discharging, and energy density.
First, let’s talk about the runtime-
It’s a 3000mAh pack. Theoretically, at 1C(3A) discharge rate, it’d run for 1 hour. At 0.5C(1.45A) and 0.1C(.3A) it’d run for 2 hours and 16 hours respectively.
But as we know, most RC vehicles require a much more discharge rate than that. Expect a 15-20 minutes runtime for 1/10 scale RC cars and crawlers.
On-demand, it can spill out a 10C(30Amp) discharge rate when your RC vehicle needs to run full-throttle. Note that, at 10C, you will only get to run it for 1-2 minutes at best.
With a 5.39″x1.87″x0.95″ of size and 11.5oz weight, it can fit any 1/10 RC vehicle. Just make sure the vehicle has a matching Tamiya connector.
Although it can be bought alone, we’ve selected the battery+charger combo. Because the smart universal charger Tenergy offers with its pack is IMPRESSIVE.
Firstly, it’s a go-to charger for all your NiMH or NiCD packs(7.2v-12V). To keep up with its compatibility, it has three adapters with it- Tamiya, standard-to-mini-tamiya, and standard-tamiya-to-mini-alligator.
The 0.9A input is for low capacity(800-1800mAH) and the 1.8A goes with higher than 1800mAh. On that note, this 3000mAh 7.2V battery we’re talking about would take about 2 hours on 1.8A.
A couple of LED indicators would show you the charging state(full/charging), no battery state, and any potential short circuit or misalignment of the battery.
MELASTA 7.2V 5000mAh NiMH Battery: More About it
If you require a massive 15-30 runtime from your 7.2 NiMH pack, 5000mAh is your bet. And This one from Melasta outsmarts other 5000mAh packs in a number of ways.
First, you’re getting a 5000mAh pack for the price of a standard 3500-4000Mah, 7.2v one. Other 5000mAh or higher battery packs like Venom cost about 10-20% more.
There are cheaper and high-discharge 5000mAh packs like this one from FlyLinkTech, but that weighs about double(980g) than this one.
As you can tell, the energy density of this pack is pretty high- 36Wh. Just to compare, the cheaper one we discussed from FlyLinkTech, has only 6.29Wh, and the premium Venom 7.2v 5000 pack has the same 36Wh.
The manufacturer usually offers a maximum of 10C discharge rate. However, note that the higher the discharge rate is, the less lasting voltage stability you’d get. For example, at 2C, you’ll get 7.2V+ output for about 20 minutes. But at 3C, it’s 12 minutes. At 5C and 10C, it’s 6 minutes and 2 minutes respectively.
As said earlier, it’s claimed to have no memory effect in this pack. But after some days of use, you’d get slightly lower(around 4750 mAh) capacity out of it.
Still, that’s a massive runtime for hobbyist RC purposes.
In terms of physical properties, it’s 450g heavy and 5.38×1.88×0.86 inches in size. A 1/10 scale RC vehicle that it’s compatible with, can easily live with that.
Talking about compatibility, it comes with a banana connector that can connect to a range of ⅛ and 1/10 scale RC cars, buggies, trucks, helicopters, quadcopters, or airplanes.
What Could Be Better?
- A multi-plug compatibility like the Venom 7.2v 5000 pack would have been great!
- Although the company denies this, it’s not a bit large for a range of 1/8 scale rc vehicles.
Danchee 7.2V 800mAh NiMH Battery: More About it
If massive runtime is not actually a priority of yours, this 800mAh 7.2V pack from Danchee deserves some attention. Apparently, regardless of the small capacity, it has some interesting selling points.
Unlike the previous two, this pack has 6 AA NiMH cells side-by-side. Together, they combine into only 100g of weight and 8.75×5.75×2.25 inches in size. That makes it a suit for any 1/12 RC crawler or truck that connects to its Mini Tamiya connector.
For such a 1/12 scale vehicle, this battery would offer 5-10 minutes of runtime while fully charged. Not bad for an 800mAh NiMH, right?
Danchee packs in a wall charger along with the battery, but it charges pretty slow. Although slow charging is actually good for battery health.
Overall it costs pretty less than what a battery+charger combo is supposed to. Apparently, it’s the only 7.2v pack in this list that comes with its own charger.
What Could Be Better?
- This one has the least compatibility on the list. It’s recommended for Danchee 1/12 crawlers only.
- The charger takes about 200 minutes to charge it from scratch. That’s way too long. Also, it’s not a smart charger and you need to keep checking on it while charging.
Best 4.8v NiMH RC Batteries
4.8V NiMH batteries come in handy for a number of purposes. Powering up RC Airplane Radios(transmitter), airplane receivers, small scale(1/16 to 1/24) vehicles- the range is pretty long.
Also, based on the cell type(AA or AAA), the capacity varies a bit. For this reason and the cell orientation, you’d find the pack shape to be either Square or Flat.
What’s Common among These 4.8V NiMH RC Batteries?
These 4.8v packs contain 4 NiMH cells, each contributing 1.2v of output. The weight of these packs lies within 0.22-0.27 lbs, which is pretty lightweight. Most of the time, they also come with pretty sealed, waterproof plastic wraps.
As it’s a 4.8V range we’re talking about, all of these packs should be charged by a USB DC port. In fact, most of them do. But for the rest, you need to get a universal charger operating within the 2.4-7.2v range.
Capacities of these packs can vary a lot, and so does the runtime. But one common problem with high-capacity(1650 mAh or more) is- they get damaged at overcharging. Even if you charge them at a high current rate, damages will take place.
Tenergy 11001 4.8V 2000mAh NiMH Battery: More About it
Among all of the single-unit 4.8V NiMH packs we’ve found, this one from Tenergy offers the best value for money. If you go for the 2-unit combo, the cost for each pack becomes unbeatable, seriously!
About connectivity, the pack contains a Hitec connector at the end of its 22 AWG silicon wire. Airplanes from Hitec, Futaba, JR, etc would be the right fits for it.
The brand claims it to run with airplane receivers-only. But the Tenergy 11001 works with Transmitters as well. Spektrum DX6i, DX7S, and other transmitters that accept 4.8v run just fine with this pack.
Let’s talk about the runtime now, shall we?
A 2000 mAh capacity can easily triple up the runtime of the stock 700mAh packs, this is a good update. You can expect about 12-20 minutes of runtime on receivers, and more than 4+ hours on radios with this battery.
If you’ve got a Futaba 6/7/8 channel radio, you need Tenergy 11002– the square-shaped version of the same pack.
Note that it doesn’t come with any charger. So you need to charge it with a good 4.8V charger that’s compatible.
What Could Be Better?
- A USB charging connector would be a great addition.
- Because of the connector, you can’t use it on RC car receivers or radios.
Blomiky 2 Pack 4.8V 2200mAH Battery: More About it
If we move a bit up the ladder, the 2-pack battery set from Blomiky is there. It has a massive 2000mAh capacity in it, offering you a few more minutes of runtime than the previous Tenergy 11001.
But what stands this one out, even more, is its compatibility. It can be used in a range of small-scale(1/16, 1/18, 1/20) RC cars, crawlers and trucks as long as the vehicles can connect to the SM-2P connector of the pack.
Plus, the built quality is pretty rugged. And you’ll get a few hundred more battery cycles out of it compared to cheaper 2-pack counterparts.
The USB charger cable offers quite a flexibility in charging. But the charge time is pretty slow- about 5-7 hours if it is 100% discharged. On a side note, this is actually good for battery health.
An LED indicator on top of the USB port would indicate the charging state, preventing it from overcharging.
There are two USB charger cables in the box. Call it to overkill or not, having two charger cables is actually nice. The batteries can be used by separate persons, or you’ll have a backup in case you lose one of them.
Capacity-wise, 2200mAh of this pack is a lot. But it’s not the biggest in the group. This 4.8v Battery Pack from Gecoty has 2400mAh in it- unbelievable!
Just in case you’re interested in a single-pack unit of this battery, here you go.
What Could Be Better?
- A bit expensive compared to the other 2000mAh 4.8v NiMH.
- The SM-2P connector limits its compatibility, unlike models like Apex RC 4.8v 2000mAh which has a JR-connector.
- The long charging time might take the test of your patience.
Dynamite DYNB0007 NiMH Battery: More About it
In search of a small, compact AAA-cell NiMH instead of regular, AA ones?
This little battery pack from Dynamite contains 4 of these AAA NiMH cells, combined into 220mAh capacity at 4.8V.
You might think- such a small capacity may not offer you a super long runtime, but that’s not always required. Especially on small scale SCTs, Rallies, Crawlers, or Truggies come into play.
In fact, 1/24 scale vehicles like this 4WD SCT RTR from Tormet requires a rather lightweight battery pack than a high-capacity one. As per battery charts, an AAA cell weighs 12-15g, where AA one’s weight is around 27-30g.
That said, as a stock replacement or backup, DYNB0007 can offer a runtime of 4-7 minutes in a 1/24 scale vehicle.
It has a Molex connector with it, which might be compatible with some 1/24 models. If not, use a Molex to Tamia converter with it. Also, any 4.8V USB charger would fit into it and would take about 15-20 minutes to charge it up.
The price is a little overkill. If you don’t mind a little drop in capacity for a cheaper price, check out the ECX Dynamite DYNB0008(4.8V 150mAh).
What Could Be Better?
- The price. You can literally get 5-10 times the capacity from AA cells of the same cost.
- Because of its rectangular-flat shape, it might not fit the battery slot for all the 1/24 models.
Best 8.4V NiMH RC Batteries
If your RC vehicle can accommodate them, 8.4V NiMH packs are the ultimate powerhouse of runtime and speed. Especially if you want an upgrade to 7.2V packs, nothing could be better than an 8.4V NiM
What’s Common Among These 8.4V NiMH RC Batteries?
The biggest perk these 8.4V packs offer is- a spike of top speed, compared to 6-pack 7.2V packs. Depending on the model, you can get up to 10mph or more top speed from an 8.4V NiMH compared to 7.2V ones.
The same goes for acceleration as well. But as that varies from model to model, we’ll get into it in individual discussions.
Structurally, these batteries contain 7 of 1.2V NiMH Sub-C cells, combining into 8.4V. They can be either flat or hump-type in terms of cell orientation.
It depends on your RC model’s battery compartment about which type would fit right into it. Often, it might require making small modifications or taking the foam spacer off to accommodate these packs.
That said, any 1/10 or ⅛ scale vehicles or heli or boats are theoretically able to run on these 8.4V NiMH packs.
Melasta 8.4V 4200mAh NiMH Battery: More About it
At the top of the list, it’s the 4200 mAh 8.4V battery pack from Melasta. Considering that one would go for an 8.4V pack for speed and acceleration, the massive 4200mAh capacity would keep the runtime untouched.
First, let’s talk about the runtime. RC truck, boat, or car- on any 1/10 or ⅛ scale vehicle, you can easily expect 20-25 minutes of runtime from it.
If you need a fast startup speed or pace up the acceleration, it can go up to 42 amp of output at a 10C discharge rate. But that would deduce the runtime as well. And this is the highest in the list because no other 8.4V comes with a 4200 mAh capacity.
It has a Traxxas female connector with it, so any RC vehicle with Traxxas male connector would be the right fit. But the battery compartment has to be as spacious as 6.29” x 1.78” x 0.93”- which is the size of the battery.
And it’d add an additional 484g of weight to your vehicle once equipped.
The charging schemes are somewhat regular- standard charge at 0.1C(0.42A) and quick charge at 0.2C(0.84C). But unofficially, you can charge it as fast as 1C(4.2A).
Note that the charging time would be a bit slower than expected. At 0.1C, it takes 13 hours(instead of 10hrs) and at a fast charge, it takes 6 hours(instead of 5 hours).
What Could Be Better?
- It’s about 100g heavier than other flat 7-cell packs like Zeee 8.4V 3000mAh. But that’s justified by the higher energy density it has.
- This pack is great for super high-top speed. But if you go for it too often, watch out for overheating issues.
- It doesn’t settle well with just any 8.4V charger. We recommend this charger from the same brand.
Zeee 8.4V 3000mAh NiMH Battery: More About it
3000mAh is a sweet spot between runtime and lightweight profile when it comes to 8.4V NiMH packs. Usually, you’ll get about 10-15 mins of runtime from one such pack.
For this and some other reasons, this battery pack from Zee Power found its place in this list.
Firstly, it’s one of the smallest and lightest flat-type 8.4v around-. It weighs 390g and measures 6.12” x 1.79” x 0.89” in size.
Secondly, it’s longevity that deserves a shoutout. You can keep using it and beat the life out of it, and it’ll still function. That’s a serious virtue for NiMh, if not all RC batteries.
It has a Tamiya plug with it that makes it a fit for an array of 1/10 and ⅛ cars, helis, and boards.
About discharging, it can go up to 10C and provide you with a 30 Amp output on demand. To charge it, it’s recommended to use a 0.5-1C(1.5-3 amp) charger.
Last but not the least, it’s a pretty well-priced battery. Call it a replacement of your stock battery or a spare one, it’s a great value for money.
What Could Be Better?
- Some claim that the battery discharges too fast and takes its toll on the runtime. Consider buying a higher mAh pack(Venom 8.4V 5000mAh or AWANFI 8.4V NiMH 4200mAh) if you find this important.
- Tamiya is a low current connector by itself. So 1/10 RC models like Arrma Granite 4×4 won’t be able to perform their best with this battery, although it’d fit well in it.
Traxxas 2926X 3000mAh: More About it
Traxxas 2926X 3000mAh Power Cell is the third and the only ‘hump’ style pick on this list. Apart from being from one of the most trusted brands in the game, it has a few standout points, which we’ll break down shortly.
But, let’s talk about why we include a hump pack first, shall we?
The first advantage of humps over flat ones is the size. This Traxxas 2926X sizes 5.47” x 1.88” x 1.65”, which is about an inch thicker but 20% shorter in length than the flat Zeee 8.4V of the same 3000mAh capacity.
Hence, it’d fit in a much smaller battery compartment, which is crucial for 1/10 or 1/12 scale vehicles sometimes.
Of course, it comes with a Traxxas connector, which is a high-current connector by default. So, it won’t stop you from stretching the limits of your vehicle.
On the downside, the 2926X doesn’t offer a fast discharging rate. You’ll get about 20 minutes of runtime though, given that no serious discharging is taking place.
With a Traxxas charger, the ideal charging time is 1 hour at 1C. Even if you want, you can go a bit faster and get it charged in 45 minutes as well.
What Could Be Better?
- No rapid discharging abilities. Hence, you can’t spike up your top speed or accelerate fast when you’re falling behind in a race.
- The extra ‘bump’ from the 7th cell might cause trouble fitting it in 1/10 or ⅛ scale RC vehicles.
- The same pack doesn’t have any ‘flat’ version.
Honorable Mentions- Best 9.6V & 12V NiMH RC Batteries
We didn’t want to stretch this list even further, as the most popular voltage categories are already talked about. But tenergy raised the bar a little higher and came up with a 9.6V and a 12V NiMH, each of 2000 mAh capabilities.
Due to their unparalleled popularity, we thought to briefly discuss these voltage giants as well. So, here we go-
Tenergy 9.6V 2000mAh: Best 9.6V NiMH RC Battery
As you can tell, there are 8 1.2 NiMH cells in this big boy, combining into 9.6V of output voltage. This would fit 1/10, ⅛ or even bigger models from brands like Nikko, Tyco, RadioShack, etc if they have a ‘Standard Tamiya’ connector.
Although there are 8 cells in it, the size is pretty compact- only 4” x 2.3” x 0.5”. The reason is, unlike Sub-C cells, AA cells are pretty smaller and lighter in weight.
The 2000 mAh might not offer the longest runtime(5-10 mins), but looking at the ‘extremely’ affordable price, you might overlook it anyway.
Also, while charging, it’s not recommended to go over 1A, which is a 0.5C charge rating.
Tenergy 12V 2000mAh: Best 12V NiMH RC Battery
Let the last installment of this list be the gigantic 12V 2000mAh NiMH battery from tenergy. The runtime is the same 5-10 mins as the previous 9.6CV one. But apart from RC vehicles, it can be used for DIY devices, LED lights, medical devices as well.
It has 10 10S1P AA NiMH cells in it, which is one scale higher than typical AA cells. 10 of these cells combined into 2.89” x 2.11” x 1.2” of size and only 255g of weight, which is a good selling point.
The user can choose one of these two charging options- 0.5C(950mA) for 2.4 hours, 0.2C(380mA) for 7 hours. But charging it at 1C might affect the battery health.
As it’s meant to be for versatile uses, it doesn’t have any of those regular connectors. Instead, there are a couple of bare leads with protection caps, and the user can modify them if needed.
Lastly, considering the number of cells and capacity, the price seems to be pretty reasonable.
Nimh Rc Battery Basic Explained
What is a Rc Nimh Battery
NiMH stands for Nickel-Metal Hydride- which is the chemical behind the cells. They are a rechargeable upgrade to good old alkaline batteries and a cheaper alternative to RC LiPo batteries.
NiMH battery technology has been around since 1970. And today, many of the RTR(Ready to Run) RC models come with NiMH as the stock battery. Although, there are other choices(LiPo, NiCD) available as RC power sources. But NiMH has a few advantages over both of them.
Sidenote: If you’d like a detour to your high school chemistry about NiMH technology, here’s a guide.
Advantages of NiMH RC Batteries over LiPo/NiCD
- NiMH batteries cost less than LiPo and NiCD batteries of the same capacity.
- They are rugged and often feature better physical endurance.
- Requires much less maintenance than LiPo and NiCD.
- Worry-free and easier to charge. Often, it’s the safest choice for RC beginners.
Understanding RC NiMH Battery Labels
For any beginner to RC, understanding the battery label is crazy important. It shows up the volts, the capacity, and other important stuff that plays serious roles while you’ll be using it.
Not all labels show the same information. But, below, we’ve circled up these terms on an ideal NiMH battery label and explained-
Nimh Rc Battery Voltage(V)
First, you’ll see the ‘voltage’ of the battery printed as 7.2V, 6.0V, 4.8V, etc. It’s the operating voltage that these battery units provide combined(explained later).
Each of the NiMH cells provides an output at 1.2V. You’ll see 4, 5, 6, or up to 10 of these cells buckled up together and offering 4.8V(4*1.2V), 6.0V(5*1.2V), 7.2V(6*1.2V), and up to 12V(10*1.2V).
Remember, Empowering an RC vehicle with less or more voltage than what it accepts, might result in some fireworks.
Nimh Rc Battery Capacity(mAh)
The biggest number(mostly 4 digits) on the label of a NiMH battery is the capacity indicator of the battery. It’s in the mAh unit, which stands for a milli-Ampere hour. Typically, it can be anything from 800mAh to 5000mAh.
Note that such comparisons of mAh capacity can only be done between batteries of the same Voltage.
Nimh Rc Battery Power Capacity(Wh)
Wh(watt-hours) is another way to measure the battery’s capacity, especially when it comes to comparing NiMH batteries of different voltages. Watt-Hours indicates how much power a battery holds. And it’s measured like below-
Power Capacity(Wh) = Voltage(V)*Capacity(Ah)
Using the formula, you can learn to compare batteries of different voltages. Before you do, convert the capacity in mAh to Ah(Ampere hour) by dividing by 1000(1A=1000 mA).
As an example, the Turnigy 3000mAh 7.2v NiMH on the image above has 7.2(V)*18(Ah)= 12.96Wh. And Zeee 8.4V 3000mAh has a power capacity of 8.4(V)*30(Ah)= 12.96Wh has 25.2Wh. So, it holds about double the energy than the Plazma one.
Here’s more about different aspects of battery capacity.
Nimh Rc Battery Discharge and Charge Rate(C Rating)
The charge and discharge rates- both as expressed in C-rating(C). About the C-rating NiMH batteries, these are often misleading.
To clear up the cloud, let’s see what is C-rating of NiMH batteries?
C-rating is the indicator of how fast or slow a battery can deliver an output or take input. Technically, it’s a measure of how much power in an hour would drain down the entire capacity of a battery.
As an example- if a 5000 mAh battery runs at 1C, it’d keep delivering 5000mAh output for 1 hour. At 2C, it’d provide 10,000mAh for 30 minutes. Running at 0.1C(C/10), it’d keep providing 500mAh for 10 hours.
Now, the charge and discharge rates of NiMH(and other) batteries are expressed in C-ratings. Here’s what they mean for the user-
The discharge rate of NiMH batteries indicates how fast and heavily it can discharge(deliver power) itself while you’ll put it into use. The C-rating printed as the discharge rate is the ‘Maximum’ C-rating that it can operate within. Usually, the max discharging rate of NiMH RC batteries is 3-15C.
Example- This Melasta 8.4V 4200mAh has a max discharge rate of 10C. Hence, it can keep supplying 42A(42000mAh) for 6 minutes(1h/10) straight.
The charge rating that’s printed on the label means all the same, just in an opposite manner. Unlike discharge rates, it’s not the highest C-rate that you can charge at, but it’s the ‘Recommended’ charge rate. Usually, the recommended charging rate of NiMH batteries is 1C-0.1C(C/10).
For example- The charge rating of Venom 7.2V 5000mAh is 1C. Meaning, it’s recommended that you charge it with a 5A charger, not more, not less. The GEILIENERGY 4.8V 2000mAh pack is recommended to charge at C/10. So, a .15A charger would be the right fit to charge this up.
How Long Do Rc Nimh Batteries Last?
The durability of NiMH RC batteries should be discussed from three aspects- the runtime, cycle count, and shelf life.
We’ll break down both of them below-
Runtime of RC NiMH Batteries
The runtime of a NiMH battery indicates how long it can supply power while fully charged. This directly depends on the battery capacity, a.k.a. mAh. As we’ve said before, the mAh of NiMH RC batteries can be anything from 800-5000 mAh.
In the most common use cases, here’s how long each of them would last, approximately-
|NiMH Battery Capacity|
|800mAh||5-8 mins||Danchee 7.2V 800mAh|
|1600mAh||8-10 mins||Venom 6v 1600mAh|
|2000mAh||12 mins||Tenergy 4.8V 2000mAh Futaba Battery Pack|
|2400mAh||12-15 mins||Gecoty 4.8v Battery Pack 2400mAh|
|3000mAh||15 mins||Tenergy 7.2V 3000mAh|
|3600mAh||20 mins||AWANFI 7.2V 3600mAh|
|4200mAh||25 mins||Zeee 7.2V 4200mAh|
|5000mAh||30 mins||MELASTA 7.2V 5000mAh|
Almost forgotten, NiMH(and all other) batteries do lose some capacity over time. For instance, at a level of 400-800 recharge, a NiMH cell would lose 10-15% of its capacity.
Lifetime Cycle Count of RC NiMH Batteries
If a battery is completely ‘discharged’ and recharged again, that’s referred to as 1 ‘cycle’ of it. Now the question is, how many cycles does an RC NiMH battery offer?
Generally, we can say these batteries would give you 500-1500 cycles before they go bad. But, truth be told, it depends on two factors. Check below-
Slower Charging Rate Boosts the Lifespan
The slower you charge a NiMH battery, the better health it will maintain. To get the most cycles out of it, charging it at C/10 or 0.1C is recommended. On the flip side, using fast chargers at 5-15C would take its toll on the longevity of the battery.
More Battery Capacity is Less Cycle Count
Even if you charge your NiMH at a slow charge rate, not each battery will last the same.
1700-2000 mAh batteries last for up to 1000 cycles. 2100-2600 mAh NiMH cells last for up to 600-800 cycles, and 5000 mAh ones might last for 200-700 cycles. All of them are considered to be charged at a slow rate as C/10 or C/5.
Shelf Life of RC NiMH Batteries
The shelf life of rechargeable batteries like NiMH depends on the ‘self-discharge rate’ of them. For NiMH, it’s 20-30%/month, which means it will lose 20-30% of its capacity(mAh). Note that about 15% of it is lost in the first few days of unuse.
That said, the usual shelf life of NiMH Rc batteries is 4-6 months by when it’d lose all of its capacity.
Tip: If you take spare NiMH cells as a backup to your regular RC batteries, do recharge them on a regular basis. Discharge manually if needed.
Compared to other battery types like NiCD(15-20%/month) or Li-ion(5-10%/month), NiMH cells have a higher self-discharge rate. So, the shelf life of NiMH is shorter than NiCD and Li-ion cells.
Therefore, here is a tip to improve the shelf life of RC NiMH batteries–
How to Improve Shelf Life of NiMH Batteries
Nobody really wants a battery that discharges and empties up fast. But as a matter of fact, NiMH cells do have fewer shelf lives- take or leave.
You can follow some of these tips to give your NiMH RC cell a boost in shelf life-
- Store it at a Cold temperature of 10°C-20°C for the longest shelf life. The usual storage temperature is -20°C To +35°C.
- While cold-storing, wrap an air-tight bag/pack around the NiMH. This won’t let the battery cell dry.
- Make sure the storage space doesn’t have any corrosive gas.
- Store it in a dry(low humidity) place.
NiMH vs Lipo vs NiCD RC Batteries
As we’re talking a lot about NiMH batteries today, let’s also bring two of its competitors into the ring- LiPo and NiCD.
NiCD is rhe Oldest & LiPo is rhe Latest Tech
Ni-CD(Nickel Cadmium) is another Nickel-based battery, which was vastly popular from 1930-1980.
From the late 1980s, NiMH started replacing Ni-CD because it’s cheaper, more durable, and higher in performance.
From 1991, when Sony Corporation brought in the era of Lithium-based batteries such as Lithium-ion and LiPo(Lithium-ion Polymer). They were of higher energy density and low maintenance and climbed their way to the top.
Now, in 2021, both NiMH and LiPo seem to cater to RC enthusiasts, depending on their needs.
NiMH is The Safest, LiPo is the Least
The battery chemistry can go south for all three of the cell types. It can be an improper discharge, exposure to hot/cold weather, or mishandling.
But LiPo batteries often react to such hiccups in very unsafe ways. Such as explosions, catching fire, etc. Although they come with a protection circuit called Battery Management System(BSM) built-in, at extreme temperatures or so, LiPos can turn into a safety hazard.
NiMH batteries have much stable cell chemistry, leading them not to require any protection circuit. Hence, they’re less likely to catch fire or overheat beyond the usual.
It’s Easier to Store Lipo Than NiMH
A lot of us have to store batteries for as short as a few months to about 5-10 years. NiMH batteries have a shorter Shelf life than LiPo batteries.
The reasons are-
- NiMH has an inability to hold charges over more than a few months.
- The power(mAH) capacity of NiMH also reduces over time.
- The output voltage also shrinks over time due to the internal resistance of NiMH.
All of these problems are significantly less prone for LiPo RC batteries. They also don’t require to fully discharge before storing, and fully recharge before using over again. Where NiMH has to go through this discharge-recharge hassle each time you’ll store them.
NiMH Has Lower Energy Density Than LiPo
Energy density is important in cell chemistry, indicating how ‘densely’ energy has been poured into a battery. Also, higher cell density implies smaller and lighter physical construction.
The units are Watt-hours/Kilogram(Wh/kg) or Watt-hours/Litre(Wh/L).
LiPo batteries offer higher energy density(110-160 Wh/kg) than NiMH cells(60-120 Wh/kg). And NiCD cells are at the bottom of the pile- 45-80 Wh/kg.
This might sound like you should go for a high-energy-density RC battery. But you actually don’t. The fact is, the denser a battery’s energy is, the shorter lifecycle it would have.
And most on and off-road RC applications don’t require such intense battery power where you need to exceed 100-120 Wh/kg of battery density.
Can you charge a NiMH battery with a nicad charger?
Yes, you can. As both NiCD and NiMH share pretty similar battery chemistry, a good NiCD charger can also charge a NiMH battery without harming the battery health.
How long to charge NiMH RC battery?
Usually, NiMH batteries should be charged for 3-10 hours, based on what charging rate you’re using. If you want fast charging, you can even go for 1C charging and it’d take just 1 hour for any NiMH pack.
What is the optimal NiMH RC battery charge rate?
The optimal charge rate for NiMH batteries is 0.5C. That means if your battery is of 2000 mAh, you should charge it with a 1-amp charger. Note that, the slower you charge, the better. So, the 0.1C charge rate is the best in this regard.
How fast do NiMH batteries discharge?
We’ve seen NiMH batteries discharge at 30C at maximum. But usually, most of the Sub-C type NiMH cells offer 10C discharge rate for RC vehicles. Note that AA battery cells might not provide more than 1C.
Do NiMH batteries leak?
No, NiMH batteries are not likely to leak most of the time. At least, compared to LiPo battery packs, NiMH packs are least likely to leak even at high temperatures.
Should you fully discharge NiMH batteries?
If you don’t want any memory effect to take place, you should fully discharge your NiMH batteries. Especially, before storing it for a long time, discharging them 100% is pretty crucial.
Wow! If you’re reading this line, you’ve just gone through a 5000-words article. We appreciate your patience, seriously!
By the way, if you found any of these discussions helpful and honed up your purchase of an RC NiMH battery, that’s a pleasure for us. If you think we’ve missed any model or category of NiMH RC batteries, you’re welcome to let us know via the comment section.