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Difference between revisions of "Vorpal The Hexapod Battery Recommendations"

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(Gamepad: Any kind of 9v battery)
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Technical info: The gamepad typically draws about 50 to 100 mA, which is mostly consumed by the Bluetooth module. Thus a 500 mAh alkaline 9v battery will last about 5 to 10 hours, while a 250 mAh NIMH rechargeable battery will last about 2.5 to 5 hours.
 
Technical info: The gamepad typically draws about 50 to 100 mA, which is mostly consumed by the Bluetooth module. Thus a 500 mAh alkaline 9v battery will last about 5 to 10 hours, while a 250 mAh NIMH rechargeable battery will last about 2.5 to 5 hours.
  
= Only Use Rechargeable Batteries for the Robot =
+
= Hexapod: Only Use Rechargeable Batteries =
 
Non-rechargeable batteries, such as alkaline batteries, cannot produce enough current (amperes) to drive the robot reliably.
 
Non-rechargeable batteries, such as alkaline batteries, cannot produce enough current (amperes) to drive the robot reliably.
  
The major types of rechargeable battery used today are Nickle Metal Hydride (NIMH), Nickle Cadmium (NICAD), and Lithium Ion (LION).
+
The major types of rechargeable battery used today are Nickle Metal Hydride (NIMH), Nickle Cadmium (NICAD), and Lithium Ion (LI-ON).
  
The robot comes with a 9v battery clip and a six-cell AAA battery holder that uses a 9v snap connector. However, you can find 6xAA battery holders with 9v snap connectors if longer battery life is desired.
+
The hexapod kit comes with a six-cell AAA battery holder that uses a female JST connector (red connector). However, you can find 6xAA battery holders and easily add a JST connector if longer battery life is desired.
  
 
Below we discuss the different options for the robot.
 
Below we discuss the different options for the robot.
  
 
== 6xAAA Rechargeable NIMH or NICAD Batteries ==
 
== 6xAAA Rechargeable NIMH or NICAD Batteries ==
You can use a 6xAAA battery holder with a 9v snap connector to power the robot using NIMH or NICAD batteries. Typical battery life for continuous use would be 15 to 20 minutes using batteries with 1000 mAh capacity.
+
You can use a 6xAAA battery holder to power the robot using NIMH or NICAD batteries. Typical battery life for continuous use after a full charge would be 15 to 20 minutes of continuous motion using batteries with 1000 mAh capacity. Of course, if the hexapod is moving sometimes and motionless other times, your actual time may be far longer.
  
 
== 6xAA Rechargeable NIMH or NICAD Batteries ==
 
== 6xAA Rechargeable NIMH or NICAD Batteries ==
  
You can use a 6xAA battery holder with a 9v snap connector to power the robot using NIMH or NICAD batteries. You can expect 30+ minutes of continuous usage using these batteries. However, because AA batteries are about twice as heavy as AAA batteries, they do put a little more stress on the servo motors.
+
You can use a 6xAA battery holder with a female JST connector to power the robot using NIMH or NICAD batteries. If the batteries are rated 2000 mAh (typical for this size) you can expect 30 minutes of continuous motion. However, because AA batteries are about twice as heavy as AAA batteries, they do put a little more stress on the servo motors.
  
== Two 18650 Size LION Batteries ==
+
== Two 18650 Size LI-ON Batteries ==
  
The "18650" battery is commonly used in flashlights and many of these are made to output high currents which easily are high enough to power the robot. Two in series will provide 7.4 volts nominal (which is enough for the robot's needs). While somewhat more expensive than other options, these batteries can provide very long battery life for the robot.  For example using two 3000 mAh 18650 cells you can expect over an hour of continuous use.   
+
The "18650" battery is commonly used in flashlights and many of these are made to output high currents which easily are high enough to power the hexapod. Two in series will provide 7.4 volts nominal (which is enough for the hexapod's needs). While somewhat more expensive than other options, these batteries can provide very long battery life for the robot.  For example using two 5000 mAh 18650 cells you can expect almost an hour of continuous motion. (However note: it is best to let the servos "rest" after several minutes of vigorous activity, you shouldn't run the robot full out for an hour!)  
  
Generally speaking, you should choose an 1865 with at least 1500 mAh capacity to ensure you are not overtaxing it. Often manufacturers will publish the number of "Amps" the battery can safely output. The robot only needs at most about 3 Amps during short surges.
+
Generally speaking, you should choose an 1865 with at least 2000 mAh capacity to ensure you are not overtaxing the batteries. Often manufacturers will publish the number of "Amps" the battery can safely output. The robot only needs at most about 3 Amps during short surges.
  
Note that these batteries require special chargers.  You can find 2 x 18650 battery holders, but you will need to solder on an appropriate connector.
+
Note that these batteries require special chargers.  You can find 2 x 18650 battery holders, but you will need to solder on a female JST connector.
  
== Do Not Use 9V Transistor Size Lithium Ion Batteries in the Robot ==
+
The battery compartment inside the robot is large enough to accommodate a typical 2x18650 battery holder.
A 9V Lithium Ion battery that looks like a standard 9v transistor battery might be tempting to use in the robot, however in general they cannot provide enough current (amperes) safely. For example, a 600 mAh LION battery can only safely output about 1 to 1.2 amps, and the robot needs double that. These cells might actually work in the robot for a time, but they will get too hot and their recharging lifespan will be compromised. They are not meant to continuously output more than about twice their capacity rating.
 
 
 
So, we do not recommend 9V transistor battery sized LION batteries for the robot.
 
  
 
= Other Options for Advanced Users =
 
= Other Options for Advanced Users =
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If you know about batteries and wish to design your own system for the robot, here are some factors to bear in mind:
 
If you know about batteries and wish to design your own system for the robot, here are some factors to bear in mind:
  
* The robot requires 2 amps during typical use but may spike up to 2.5 amps for short periods.
+
* The robot requires 2 amps during typical use but may spike up to 2.5 to 3 amps for short periods.
 
* The voltage regulator requires 6.5 volts input to keep the servos powered at 5.0 volts nominal, so do not design a battery system with less than about 6.5 volts output at 2 amps. Running the servos with too low voltage may shorter their life.
 
* The voltage regulator requires 6.5 volts input to keep the servos powered at 5.0 volts nominal, so do not design a battery system with less than about 6.5 volts output at 2 amps. Running the servos with too low voltage may shorter their life.
 
* The maximum recommended battery voltage is 12.0 volts, beyond that the 5v regulator used for the servos might be damaged and the Arduino Nano onboard regulator (which is fed directly off the battery, not the 5v regulator used for the servos) might overheat.
 
* The maximum recommended battery voltage is 12.0 volts, beyond that the 5v regulator used for the servos might be damaged and the Arduino Nano onboard regulator (which is fed directly off the battery, not the 5v regulator used for the servos) might overheat.
  
Example 1: the robot will run quite well on two AA LIFEPO4 batteries (which have 3.2v nominal cell voltage and when charged will meet the 6.5 volt minimum, and can output easily 3 amps). You would probably need to get a 2xAA battery holder and solder on a 9v clip, or make a converter to go from 9v clip to some other battery connector such as JST or Tamiya.  Note that LIFEPO4 batteries require special smart chargers and preferably balance chargers.
+
Example 1: the robot will run quite well on two AA LIFEPO4 batteries (which have 3.2v nominal cell voltage and when charged will meet the 6.5 volt minimum, and can output easily 3 amps). You would probably need to get a 2xAA battery holder and solder on a female JST connector.
  
 
= Changing the Battery Connector =
 
= Changing the Battery Connector =
This is a build-it-yourself robot, so if you wish to use other styles of battery connectors such as JST, Tamiya, PowerPole, or XT60, go right ahead and make the change. A few minutes with a soldering iron is all it takes.
+
This is a build-it-yourself robot kit, so if you wish to use other styles of battery connectors such as Tamiya, PowerPole, or XT60, go right ahead and make the change. A few minutes with a soldering iron is all it takes.

Revision as of 22:06, 10 July 2017

There are several battery types that will successfully power your VH12 Hexapod. The batteries you choose will affect how long the robot will run, recharge time, etc.

This article explains your options.

Battery Safety Tips

Rechargeable batteries are by far the most cost effective and environmentally friendly kind of batteries, but some simple safety rules are recommended:

  • Never, ever put non-recharegable batteries in a battery charger!
  • Do not mix different types of battery, do not mix old and new batteries.
  • If you are using rechargeable batteries, make sure you are using the right kind of charger for the batteries you are using. Follow all manufacturer recommendations.
  • Never leave batteries charging unattended. Never charge batteries "overnight". It is safest to charge batteries in a place that will not be damaged by heat, just in case the rare instance of a damaged battery overheating during charging occurs.
  • Investing in a "smart" charger is well worth the extra cost, as they will generally keep your batteries in much better shape than "dumb" chargers. You can buy a dumb charger for under $10, but if it damages your batteries so they can't hold a full charge, did you really save any money? A good smart charger is about $25 but will keep your batteries running for many hundreds of charges. Don't be penny wise and pound foolish!
  • If you are charging batteries, it is normal for them to get warm, but if they feel hot, if smoke is coming off them, if you smell a "burning plastic" type odor, if you see sparks, or if they appear to be swelling or discoloring, disconnect the charger immediately from the wall socket and wait for things to cool down before touching. Exercise caution, remove smoking batteries to the outdoors or a ventilated area.
  • If there is any visible damage to a battery or if it appears to be swelling, stop using it immediately and do not attempt to recharge it.
  • Some kinds of rechargeable battery cannot be disposed in the trash but must be recycled, follow all instructions and markings on the battery and follow your local community recycling practices.

Gamepad: Any kind of 9v Transistor Battery

The gamepad has minimal power requirements and can be powered by either non-rechargeable or rechargeable 9v transistor batteries. (These are the common rectangular batteries often used in smoke detectors, small radios, clocks, etc.) Alkaline, NIMH, NICAD, or LION batteries in the 9v rectangular format will all work fine for the gamepad. The gamepad was designed to fit a standard 9v battery in its battery compartment. You can expect several hours of usage. Do be sure to turn the gamepad off when not in use.

Technical info: The gamepad typically draws about 50 to 100 mA, which is mostly consumed by the Bluetooth module. Thus a 500 mAh alkaline 9v battery will last about 5 to 10 hours, while a 250 mAh NIMH rechargeable battery will last about 2.5 to 5 hours.

Hexapod: Only Use Rechargeable Batteries

Non-rechargeable batteries, such as alkaline batteries, cannot produce enough current (amperes) to drive the robot reliably.

The major types of rechargeable battery used today are Nickle Metal Hydride (NIMH), Nickle Cadmium (NICAD), and Lithium Ion (LI-ON).

The hexapod kit comes with a six-cell AAA battery holder that uses a female JST connector (red connector). However, you can find 6xAA battery holders and easily add a JST connector if longer battery life is desired.

Below we discuss the different options for the robot.

6xAAA Rechargeable NIMH or NICAD Batteries

You can use a 6xAAA battery holder to power the robot using NIMH or NICAD batteries. Typical battery life for continuous use after a full charge would be 15 to 20 minutes of continuous motion using batteries with 1000 mAh capacity. Of course, if the hexapod is moving sometimes and motionless other times, your actual time may be far longer.

6xAA Rechargeable NIMH or NICAD Batteries

You can use a 6xAA battery holder with a female JST connector to power the robot using NIMH or NICAD batteries. If the batteries are rated 2000 mAh (typical for this size) you can expect 30 minutes of continuous motion. However, because AA batteries are about twice as heavy as AAA batteries, they do put a little more stress on the servo motors.

Two 18650 Size LI-ON Batteries

The "18650" battery is commonly used in flashlights and many of these are made to output high currents which easily are high enough to power the hexapod. Two in series will provide 7.4 volts nominal (which is enough for the hexapod's needs). While somewhat more expensive than other options, these batteries can provide very long battery life for the robot. For example using two 5000 mAh 18650 cells you can expect almost an hour of continuous motion. (However note: it is best to let the servos "rest" after several minutes of vigorous activity, you shouldn't run the robot full out for an hour!)

Generally speaking, you should choose an 1865 with at least 2000 mAh capacity to ensure you are not overtaxing the batteries. Often manufacturers will publish the number of "Amps" the battery can safely output. The robot only needs at most about 3 Amps during short surges.

Note that these batteries require special chargers. You can find 2 x 18650 battery holders, but you will need to solder on a female JST connector.

The battery compartment inside the robot is large enough to accommodate a typical 2x18650 battery holder.

Other Options for Advanced Users

If you know about batteries and wish to design your own system for the robot, here are some factors to bear in mind:

  • The robot requires 2 amps during typical use but may spike up to 2.5 to 3 amps for short periods.
  • The voltage regulator requires 6.5 volts input to keep the servos powered at 5.0 volts nominal, so do not design a battery system with less than about 6.5 volts output at 2 amps. Running the servos with too low voltage may shorter their life.
  • The maximum recommended battery voltage is 12.0 volts, beyond that the 5v regulator used for the servos might be damaged and the Arduino Nano onboard regulator (which is fed directly off the battery, not the 5v regulator used for the servos) might overheat.

Example 1: the robot will run quite well on two AA LIFEPO4 batteries (which have 3.2v nominal cell voltage and when charged will meet the 6.5 volt minimum, and can output easily 3 amps). You would probably need to get a 2xAA battery holder and solder on a female JST connector.

Changing the Battery Connector

This is a build-it-yourself robot kit, so if you wish to use other styles of battery connectors such as Tamiya, PowerPole, or XT60, go right ahead and make the change. A few minutes with a soldering iron is all it takes.