If you have a Traxxas RC car you might want to change from one battery type to another. LiPo batteries provide more power but are also considerably more expensive than NiMH and are more difficult to charge.
How you would change your Traxxas RC car from LiPo to NiMH would depend on which Lipo and NimH batteries you’re looking to switch between. It would also depend on the cutoff voltage settings on your controller (ESC). If the cutoff is set to LiPo Low then what it will detect will be an 8 cell NiMH as 3S Lipo, and cut off at 8.55V.
This is 1.07V/cell, and what it means is that you won’t quite get the full capacity out of your NiMH pack. If the cutoff is set to NiMH High then with 3S Lipo it will cut off at at 8.1V (65% of 12.5V) which typically puts you at a risk of over-discharging the LiPo.
There’s nothing to stop you from using the same settings for both, as long as you understand the limitations of doing that. So, read your manual carefully. If you ensure that your batteries are fully charged all the time before use and if you time your flights to avoid going into cutoff, which is always a good idea, then you can set the ESC to NiMH High and it will be just great for both your Lipo and NiMH.
To see how to change from LiPo to NiMH mode on a Traxxas RC car you can check out the video below.
Differences Between NiMH and LiPo Batteries
The most significant difference between NiMH and LiPo batteries is the chemical properties that make it possible for the batteries to charge. NiMH (Nickel-metal hybrid) makes use of nickel-based technology while LiPo (Lithium Polymer) batteries make use of a lithium-ion technology.
Speaking of what these two types of batteries have in common, both battery types store a certain amount of energy depending on their capacity. Batteries could be manufactured with different voltages and capacities by the installation of battery cells in series or parallels inside the battery pack.
Dropping the batteries or damaging the cases of the battery cells can result in a short circuit so it is important to be very careful with them no matter which type you have. When you are throwing away each battery, each of these battery types needs to be disposed of properly to avoid having any issues.
The two battery types are very different in their properties and their uses.
NiMH batteries are typically a lot easier to use than LiPos. Keep in mind that NiMH batteries must be fully discharged before charging and they must be charged fully before they’re stored unless the manufacturer states otherwise which may be the case with Traxxas.
NiMH battery chargers are equally very easy to use.
LiPo batteries, on the other hand, don’t need to be fully discharged and they have to be stored with a 50−70% charge level. LiPo batteries also have to be charged with balanced charging. For safety purposes, it is best to charge and store LiPo batteries in a LiPo safe bag.
What You Need to Know About NiMH Batteries
- It offers easy and worry-free charging and storing which makes it the safer option for beginners.
- It has a rated cell voltage of 1.2V.
- It has to be fully discharged before it is charged. Also keep in mind that you should fully discharge the battery in order to make sure that the full battery capacity is kept available.
- They have to be stored fully charged unless the manufacturer states otherwise.
- The batteries are made with standard sized cells with metal cases
What You Need to Know About LiPo Batteries
- LiPo batteries come with a rated cell voltage of 3.0V when discharging.
- LiPo batteries must always be charged using a charger with balanced charging.
- LiPo batteries have to be stored with a 50−70% charge level. The voltage per cell is 3.85V−3.9V.
- It is always safer to use a LiPo safe bag when charging as well as when storing in order to reduce the risk of hazards.
- LiPo batteries don’t have to be fully discharged before they are charged.
LiPo batteries also have quite a number of advantages that NiMH batteries do not.
For starters, the weight and power ratio of LiPo batteries is significantly better than those of NiMH batteries. LiPo batteries are also significantly lighter and can be stored at the same amount or more energy than NiMH batteries relative to their capacity.
In addition, LiPo batteries put out more power and in greater quality than NiMH batteries. The power output of LiPo batteries is steady through the duration of the discharge, while the power output of NiMH batteries typically begins to decrease soon after charging because NiMH batteries typically have a higher discharge rate.
So, when you have a LiPo battery with the same capacity as a NiMH battery, you can expect the LiPo battery to deliver a longer runtime and better performance than the NiMH battery.
Safety Tips for LiPo Batteries
Seeing as LiPo batteries are generally more dangerous, here are some safety tips for LiPos:
- Never charge, discharge, use, or store a puffy or bad LiPo battery. Immediately discontinue use and dispose of the batteries properly.
- Always use the right LiPo battery balance charger/discharger. It is important that all the cells in a LiPo battery stay at the same voltage across all cells all the time. If the voltages across the cells are too different from each other (5mV ~ 10Mv), the battery may become unstable and dangerous. However, if it’s a single cell LiPo, you don’t have to worry about cell balance.
- Always ensure that you’re using a fireproof LiPo safety bag, metal ammo box, or any other fireproof container when charging, discharging, or storing your LiPo batteries to prevent the risk of any hazards. While LiPo fires may not happen often, they can happen quite quickly and dangerously. An internal short circuit is enough to set the battery off and you can’t tell when it will happen. However, keep in mind that the tendency is higher when LiPo batteries are fully charged, being overcharged, or being discharged, even though it can happen at any time.
- Avoid filling the container to capacity with your batteries and always follow the recommendations of the manufacturer for how many mAhs a LiPo bag can safely contain.
Changing from one battery type to another is relatively easy as long as you read the manual and make sure that all of the electronics will work properly with the new battery type.
Many people prefer to go from a NiMH battery to a LiPo because of the increase in power, speed, etc. but if you use your RC car a lot NiMH batteries will last much longer than LiPOs before they need to be replaced.
Whether you prefer to have more power while using and have to replace the battery more often or prefer less power with each run but save money by not having to replace the battery is a very personal decision.
Virtually all RC cars can be changed to use different battery types but you have to make sure to do it properly so you don’t mess up the new battery or the RC car’s electronics.