Charging a NiMH battery can be a very intricate process. Plus, there could be disastrous incidents if you overcharge it. For this, you’ll need to know how much time you’ll need to charge these batteries.
So, how long does it take to charge an 800-5000mAh NiMH battery?
The charging time can vary anywhere between 2.5-15 hours. This variation occurs due to the overnight, fast, and trickle charging methods. The overnight charging takes longer compared to the fast charging method. On the other hand, trickle charging can take over 15 hours.
This was merely the tip of the iceberg. Want to know more about the specifics in detail? Well, jump right into the segment down below!
Contents
Does the Charging time of Nimh Depend on mAh?
Yes, the charging time of NiMH batteries depends on mAh capacity. In the case of this battery, these variables are proportionally related. This means, larger mAh will mean more charging time compared to smaller capacity ones.
For example, your NiMH battery of 5000mAh will have more runtime than 3000mAh.
What is mAh in NiMH battery?
The mAh is the short form of milli-ampere hours. It’s the rating of energy storage capacity a battery has. Every battery, including the NiMH batteries, uses this mAh standard to show its capacity.
Suppose, a NiMH battery has a 1000mAh capacity. It means that the battery can store 1000 milli-ampere hours worth of energy in its cell. So, when it’s charged, it’ll need to charge it up to 1000mAh to get it fully charged.
Here the charging time may vary between 3-5 hours depending on the method you choose. Now let’s check out these different variations.
3 Kinds of Charging Rates for NiMH: Explained
There are 3 kinds of charging methods you can use to charge your NiMH battery. The time variation is caused by these different methods. This also ensures that your battery’s cells don’t get damaged or overcharged.
However, if you’ve got a lipo battery, then this charging time will vary based on the voltage of the battery. Now, let’s get going-
Recommended Or Overnight Charging
This is the cheapest, easiest, and slower method to charge your batteries. It has a capacity rate of C/10 or lower and charges about 10% per hour. Usually, the time varies from 5-12 hours depending on its mAh capacities. We’ll see that in a little bit.
Fast Charging
Fast Charging can be done by charging the battery at C/5.33. The chargers also come with special sensors. These sensors keep tabs on the battery’s temperature, charge rate while charging.
It also times the charging period. Hence, once fully charged, it’ll stop charging the cells. This will prevent overcharging! Now, it might be risky for the battery cells. But it’s the fastest way to fully charge your batteries within 5 hours.
Trickle Charging
This is the method you can use to top up your batteries without damaging them. The process can be done safely between 0.03C and 0.05C current rate.
However, in this case, you need to regulate the charger flow and maintain the temperature. This is because the voltage is dependent on it.
Recommended or Overnight Charging Time for NiMH Cells
This method can be a little time-consuming, so use this when you’ve got time. Because depending on your capacity it might extend up to 16 hours. Also considering the charger is less than 0.1C.
What Chargers to Use for Overnight Charging?
You should buy a dedicated NiMH charger for this. Chargers like the POWXS Universal NiMH Battery Charger are the best options in this case.
This will ensure fully charged batteries without any damage. The nominal 1.2V and fully charged 1.5V will be maintained by the charger.
But before you get to the charging part, make sure your RC has a good battery connector. For this, you have to know the difference between good connectors like EC3 and EC5. This will make the entire process much smoother.
How Long to Overnight-Charge NiMH RC Batteries
We’ve listed the time limit according to battery capacity for your easier understanding. The charger current will be shown on the body of your device as well. So, you can also check it from there.
Here’s a rule of thumb you can use to calculate the time:
Charging Time = Battery Capacity Output Capacity
| Battery Capacity | Output Capacity | Charge Time |
| 800mAh | 400mAh | 2.4 hours |
| 1600mAh | 400mAh | 4.8 hours |
| 2000mAh | 400mAh | 6 hours |
| 2400mAh | 400mAh | 7.2 hours |
| 3000mAh | 400mAh | 9 hours |
| 3600mAh | 400mAh | 10.8 hours |
| 4200mAh | 400mAh | 12.6 hours |
| 5000mAh | 400mAh | 15 hours |
Fast Charging Time for NiMH Cells
Fast Charging is comparatively a lot faster than overnight charging. It’ll charge the batteries at a C/3.33 charge rate. However, you have to be cautious, otherwise, there’s a chance you’ll risk overcharging.
What Chargers to Use for Fast Charging?
You need to use a NiMH charger that is capable of fast charging. Powerowl 8 bay Fast Charger are the best chargers in the market. This can be a great product that’ll maintain your battery’s health as well!
How Long to Fast-Charge NiMH RC Batteries
With a voltage of C/3.33, they’ll charge about 50% faster than overnight charging. But there will be variations depending on the capacity. So, here’s a rule of thumb you can use to calculate the charging time:
Charging Time = Battery Capacity Output Capacity
| Battery Capacity | Output Capacity | Charge Time |
| 800mAh | 600mAh | 1.6 hours |
| 1600mAh | 600mAh | 3.2 hours |
| 2000mAh | 600mAh | 4 hours |
| 2400mAh | 600mAh | 4.8 hours |
| 3000mAh | 600mAh | 6 hours |
| 3600mAh | 600mAh | 7.2 hours |
| 4200mAh | 600mAh | 8.4 hours |
| 5000mAh | 600mAh | 10 hours |
Trickle Charging Time for NiMH Cells
In the case of trickle charging, the charger is always on standby mode. They have a charge rate between 0.03C to 0.05C. Thus it can safely charge the batteries without damaging the cells.
What Chargers to Use for Fast Trickle?
For NiMH trickle charging, you can use chargers like the FOVAL trickle battery charger. This will keep your batteries topped up. Moreover, the charger here will act as a filler and charge the batteries to maximum capacity.
How Long to Trickle-Charge NiMH RC Batteries
Trickle charging will take the longest to charge to full capacity. The charge happens at the rate of C/10. Here the charging time stays constant. However, the output capacity varies according to the battery capacity.
You can use the same method here to calculate the time:
Charging Time = Battery Capacity Output Capacity
| Battery Capacity | Max mA Output Capacity | Charging Time |
| 800mAh | 26.4 mA | 31 hours |
| 1600mAh | 52.8 mA | 31 hours |
| 2000mAh | 66 mA | 31 hours |
| 2400mAh | 79.2 mA | 31 hours |
| 3000mAh | 99 mA | 31 hours |
| 3600mAh | 118.8 mA | 31 hours |
| 4200mAh | 138.6 mA | 31 hours |
| 5000mAh | 165 mA | 31 hours |
Can You Overcharge NiMH Batteries?
No, you can’t overcharge NiMH batteries. This is because it can damage the cell capacity and life cycle permanently. Moreover, the temperature will also start to increase causing the cell separators to lose electrolytes. This can make the battery lose its charging capacity exponentially.
To check if your battery has gone bad, you can take help from a multimeter. If you don’t see reading this might be an indication of faulty batteries. Hence you have to replace them with new ones.
Now, to save you from the trouble of looking through batteries, we’ve recommended some batteries here:
| Image | Title | Price |
|---|---|---|
  | Tenergy 9.6V Flat NiMH Battery Packs for RC Car, High Capacity 8-Cell 2000mAh Rechargeable Battery | Check Price |
  | 7.2V 5000mAh NIMH Battery for RC Cars, 6-Cell Flat Rechargeable Battery Pack | Check Price |
Have a look at these options, and choose the one you like. About the performance, you don’t have to worry. This is because these are the best in the market.
However, if you feel like it then you can also replace NiMH batteries with LiPo batteries.
Well, that’s all we have on this segment!
FAQs
Can I charge the NiMH battery with a NiCd charger?
No! Never charge your NiMH batteries with NiCd chargers. Both have significant differences in charging conditions. If you use a NiCd charger to charge a NiMH battery, you’ll most likely damage your batteries.
Can I charge NiMH batteries in series?
Yes. You can charge your NiMH batteries in series. It’s safe as long as your batteries have the same capacity. Otherwise, you’ll have to charge them parallelly. Therefore, before you charge your batteries, check whether the capacities are the same!
How fast can I charge NIMH batteries?
You can charge your NiMH batteries faster by setting the charge rate at 1C. It can charge your batteries within an hour or so. For a faster recharge time, you’ll need to buy an ultra-fast charger. This will definitely speed up the charging time.
Verdict
We hope we’ve clarified all your confusion. Well, you can now tell how long does it take to charge a 800-5000mAh NiMH battery.
From a safety and longevity perspective, it’s better to use the overnight charging method. This does not damage your batteries and also charges it to its maximum level!
Have a great day!
