Batteries

[whites75]

Can someone tell me a bit about batteries please. Watching stuff on youtube I keep seeing the phrase like 2's or 3's when referring to the battery. Why would you use the bigger battery, does it just make the car quicker. Also how do you know if the battery is right for a specific model of car.

Reason I ask is I am due to get a buggy and sct soon and will want extra batteries so just wanna make sure I get the right ones but also why would I choose one over the other please?

My dad has a brushed ftx carnage which one battery says 1700 nimah or something on it but the other says 3000 on it. This I am going to use as a general bashing car once I upgrade it to a brushless motor

cheers team

[jcb]

Batteries can seem overly complicated and there are a number of options from Nicd, Nimh, LIPO and LIFE.

Personally I would recommend that you discuss your options with the local model shop or club and would also divert you to the electric board on the BRCA website, www.brca.org this lists a number of batteries which are all deemed as safe to use by the sports governing body.

As a rough guide you will require a battery with a nominal voltage of 7.2volts or 7.4volts for a 1/10 scale battery. This would equate to either 6 x 1.2volt nimh or nicd batteries or a 2s LIPO battery. The S on lipo seems to relate to the nominal voltage of a battery in this case it is 3.7volts, so 2s is 2 x 3.7volts.

The mah relates to the batteries capacity, which is basically how big the fuel tank is, so the higher the mah the longer the car will run for. It may also make the car a little bit faster than if using a lower capacity battery.

Please also make sure that you use the appropriate charger for the type of battery you purchase.

[whites75]

many thanks for the info

Originally Posted by jcb

Batteries can seem overly complicated and there are a number of options from Nicd, Nimh, LIPO and LIFE.

Personally I would recommend that you discuss your options with the local model shop or club and would also divert you to the electric board on the BRCA website, www.brca.org this lists a number of batteries which are all deemed as safe to use by the sports governing body.

As a rough guide you will require a battery with a nominal voltage of 7.2volts or 7.4volts for a 1/10 scale battery. This would equate to either 6 x 1.2volt nimh or nicd batteries or a 2s LIPO battery. The S on lipo seems to relate to the nominal voltage of a battery in this case it is 3.7volts, so 2s is 2 x 3.7volts.

The mah relates to the batteries capacity, which is basically how big the fuel tank is, so the higher the mah the longer the car will run for. It may also make the car a little bit faster than if using a lower capacity battery.

Please also make sure that you use the appropriate charger for the type of battery you purchase.

[HOTSHOT III]

If you decide to go for LiPo (which TBH is what most people use for racing these days) have a look at this guide. It was written by an RC helicopter flier but all the info is basically the same for cars:

http://www.rchelicopterfun.com/rc-lipo-batteries.html

It's a bit of a long read but when I started racing in 2011 I knew literally nothing about LiPo and I just basically read it a few times and got started, everything you need to know is there

[Peakey]

The S in lipo stands for cells so 1s is 1 cell, 2s is 2 cell and so on and so forth. This is a very good thread about lipos:
http://www.msuk-forum.co.uk/topic/21...ated-march-10/

they can seem daunting but as with everything if your careful you'll be ok

[cutting42]

Originally Posted by Peakey

The S in lipo stands for cells so 1s is 1 cell, 2s is 2 cell and so on and so forth.

Sort of, the letter S really really refers to the cells in [S]eries. Each Lipo cell is nominally 3.7 volts. With battery cells if you connect the negative of one cell to the positive of a second cell this is what is meant by connecting in series and the voltage will double if you measure from the positive of the first cell to the negative of the second cell you will see 7.4 volts. This is a 2S battery, 3S are three cells in series giving 11.1 volts, 4S = 14.8v and so on.

You can connect batteries in parallel as well giving the same voltage but doubling the capacity so you could have a 2S2P (P for parallel) battery giving 7.4 volts and double the capacity using 4 cells, 2 parallel pairs in series.

[cutting42]

Originally Posted by whites75

Can someone tell me a bit about batteries please. Watching stuff on youtube I keep seeing the phrase like 2's or 3's when referring to the battery. Why would you use the bigger battery, does it just make the car quicker. Also how do you know if the battery is right for a specific model of car.

Reason I ask is I am due to get a buggy and sct soon and will want extra batteries so just wanna make sure I get the right ones but also why would I choose one over the other please?

My dad has a brushed ftx carnage which one battery says 1700 nimah or something on it but the other says 3000 on it. This I am going to use as a general bashing car once I upgrade it to a brushless motor

cheers team

Two main types of batteries you will come across, Nickel Metal Hydride (NiMH) and Lithium Polymer (LiPO). Lipo are newer, offer much more ability to deliver lots of power quickly and have taken over all racing and most bashing.

NiMH are often packaged in ready to run kits and are fine but are an older technology. You can fully discharge a NiMH with no ill effects but you are recommended not to top up charge them, fully discharge and then fully charge - known as a cycle - from new and after storing.

LiPO must never be discharged lower than 3 volts per cell (many people don't discharge lower than 3.2 volts) or they will be ruined. However you can "top up" charge them so many people run a race, then top up the same battery ready for the next race. They must not be left full charged or discharged but in a state called "storage charge" around 3.6 volts per cell. Because a LiPO battery must not be discharged below 3 volts all modern Electronic Speed Controllers (ESC) have a built in LiPO cutoff so the car will slow dramatically when the voltage drops to 3 volts or so and will stop completely if you do not stop driving quickly. For this reason, only use LiPO batteries on an ESC that is designed to use them and has a Low Voltage Cutoff (LVC).

All batteries have a capacity measured in milliamperes per hour or mAh/hr. This is the number you have read on the batteries like 1700 mAh or 3000 mAh. These are typical values for a NiMH battery and a 1700 might just get you through a 5 min race.

LiPO's typically have much higher capacities from 5000mAh to 7000mAh which should keep you running for 20 - 30 minutes, great for bashing.

As my previous post the "S" refers to cells in (s)eries in the battery. More battery cells equals more voltage which means a faster motor speed. For racing all 10th off road is done on 2S (7.4v) and 3S is not needed or permitted AFAIK. For bashing you are free to do whatever and many use 3S to get faster motors speeds and therefore higher top speeds.

Most cars will be designed for a certain battery and can also be different shapes. Most common in NiMH are the 6 cell stick pack and rounded in shape. LiPO's are usually in a square hard case for most racing cars and are in "Stick", Shortie" or "Saddle Pack" format and your car will determine which one you should use.

You can get soft pack LiPO's but they are not allowed for racing and are more vulnerable to being punctured in a crash. This is a bad thing and can allow the pack to catch fire and the universe will end!

Hope this helps a little.

[whites75]

Originally Posted by cutting42

Two main types of batteries you will come across, Nickel Metal Hydride (NiMH) and Lithium Polymer (LiPO). Lipo are newer, offer much more ability to deliver lots of power quickly and have taken over all racing and most bashing.

NiMH are often packaged in ready to run kits and are fine but are an older technology. You can fully discharge a NiMH with no ill effects but you are recommended not to top up charge them, fully discharge and then fully charge - known as a cycle - from new and after storing.

LiPO must never be discharged lower than 3 volts per cell (many people don't discharge lower than 3.2 volts) or they will be ruined. However you can "top up" charge them so many people run a race, then top up the same battery ready for the next race. They must not be left full charged or discharged but in a state called "storage charge" around 3.6 volts per cell. Because a LiPO battery must not be discharged below 3 volts all modern Electronic Speed Controllers (ESC) have a built in LiPO cutoff so the car will slow dramatically when the voltage drops to 3 volts or so and will stop completely if you do not stop driving quickly. For this reason, only use LiPO batteries on an ESC that is designed to use them and has a Low Voltage Cutoff (LVC).

All batteries have a capacity measured in milliamperes per hour or mAh/hr. This is the number you have read on the batteries like 1700 mAh or 3000 mAh. These are typical values for a NiMH battery and a 1700 might just get you through a 5 min race.

LiPO's typically have much higher capacities from 5000mAh to 7000mAh which should keep you running for 20 - 30 minutes, great for bashing.

As my previous post the "S" refers to cells in (s)eries in the battery. More battery cells equals more voltage which means a faster motor speed. For racing all 10th off road is done on 2S (7.4v) and 3S is not needed or permitted AFAIK. For bashing you are free to do whatever and many use 3S to get faster motors speeds and therefore higher top speeds.

Most cars will be designed for a certain battery and can also be different shapes. Most common in NiMH are the 6 cell stick pack and rounded in shape. LiPO's are usually in a square hard case for most racing cars and are in "Stick", Shortie" or "Saddle Pack" format and your car will determine which one you should use.

You can get soft pack LiPO's but they are not allowed for racing and are more vulnerable to being punctured in a crash. This is a bad thing and can allow the pack to catch fire and the universe will end!

Hope this helps a little.

wow - easy to confuse yourself if your a numpty like me lol - so when I get my car I will buy lipo batteries - my dad has the nimah batteries and they last for like 10mins before the car goes pretty slow which is naff, with lipo's I can get a proper play/practice with them, especially if I have 2/3 at the ready

Regarding the cut off when the get down to 3 volts - does the esc tell you on the display how much voltage is left on the lipo or is it just a case of making note of the time you start using it and stopping as soon as the power drops?
cheers

[HOTSHOT III]

Originally Posted by whites75

wow - easy to confuse yourself if your a numpty like me lol - so when I get my car I will buy lipo batteries - my dad has the nimah batteries and they last for like 10mins before the car goes pretty slow which is naff, with lipo's I can get a proper play/practice with them, especially if I have 2/3 at the ready

Regarding the cut off when the get down to 3 volts - does the esc tell you on the display how much voltage is left on the lipo or is it just a case of making note of the time you start using it and stopping as soon as the power drops?
cheers

TBH with a decent LiPo/brushless setup a lot of people find themselves having to take a break before the batteries get down to cutoff voltage-LiPo gives such consistent power for so long that the human runs flat before the batteries

RE ESC cutoff, most speedos show a noticeable drop in power when the LiPo reaches its cutoff voltage and that's the time to stop driving. Also a lot of ESCs have the facility for the user to program the cutoff voltage, I have mine set at 3.4v per cell for an extra bit of insurance.

[JonyNitro]

If your stuck go see jeff at Elite Models Halifax local shop and plenty of car knowledge, that's your best bet