Batteries - Revision history

RobotRobot: Link LiPo Battery Safety; update fire advice and 2026 FAA travel rules

2026-10-17T06:25:39Z

Link LiPo Battery Safety; update fire advice and 2026 FAA travel rules

← Older revision		Revision as of 06:25, 17 October 2026
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	== Safety ==		== Safety ==
	See the Roger's Hobby Center page for more info (link above). Rules of thumb:		See '''[[LiPo Battery Safety]]''' for charging, storage, damaged packs, fires and disposal, and the Roger's Hobby Center page for more info (link above). Rules of thumb:

	* Use the right charger type (and settings)		* Use the right charger type (and settings)
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	* Discard damaged / puffy battery packs		* Discard damaged / puffy battery packs

	~~Do not extinguish~~ a LiPo ~~battery~~ fire ~~with water; place~~ it ~~in sand,~~ in a metal container, ~~or on concrete pavement far~~ from flammable materials.		If a LiPo catches fire at an event, the usual approach is to contain it in a metal container with sand and get it outdoors, away from flammable materials and people – follow the event's procedure. Elsewhere, fire safety agencies advise cooling burning lithium batteries with plenty of water if it's safe to do so. See '''[[LiPo Battery Safety]]'''.

	== Battery types (chemistry) ==		== Battery types (chemistry) ==
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	Keep LiPo batteries physically protected to avoid puncture, which can start a fire.		Keep LiPo batteries physically protected to avoid puncture, which can start a fire.

	If traveling by air with LiPo or other Lithium-based types, read and adhere to all aircraft safety regulations concerning these types of batteries. Here is the '''[https://www.faa.gov/~~newsroom~~/~~lithium~~-batteries~~-baggage~~ FAA ~~Summary~~]''' for the United States. As of ~~2019~~, LiPo batteries must be ~~hand~~ carried ~~aboard~~. You should keep them in your LiPo charging bag for safety.		If traveling by air with LiPo or other Lithium-based types, read and adhere to all aircraft safety regulations concerning these types of batteries. Here is the '''[https://www.faa.gov/hazmat/packsafe/airline-passengers-and-batteries FAA guidance for airline passengers]''' for the United States. As of 2026, spare LiPo batteries must be carried in carry-on bags, not checked bags, with their terminals protected; batteries over 100 Wh need airline approval. You should keep them in your LiPo charging bag for safety. See '''[[LiPo Battery Safety#Travel\|LiPo Battery Safety]]''' for details.

Chklnk: More series/parallel; more on chargers; promote safety to top; travel note; general edits

2023-12-17T11:48:02Z

More series/parallel; more on chargers; promote safety to top; travel note; general edits

← Older revision		Revision as of 11:48, 17 December 2023
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	[[File:Lipo_Battery.jpg\|thumb\|Lithium Polymer Battery]]		[[File:Lipo_Battery.jpg\|thumb\|Lithium Polymer Battery]]

	Although compressed gas or internal combustion engines are occasionally used (especially for weapons), batteries are used throughout combat ~~robots~~. There are too many batteries to choose from to make any meaningful list here, so we list some criteria to consider when choosing a battery.		Although compressed gas, hydraulics, or internal combustion engines are occasionally used (especially for weapons), batteries are used throughout combat robotics. There are too many batteries to choose from to make any meaningful list here, so we list some criteria to consider when choosing a battery.

	[https://rogershobbycenter.com/lipoguide Roger's Hobby Center] has a really good guide to lipo batteries.		'''[https://rogershobbycenter.com/lipoguide Roger's Hobby Center]''' has a really good guide to lipo batteries.

	~~== Battery types (chemistry) ==~~		<br />
	Nearly all combat robots now run on lithium polymer (LiPo) battery packs. They have very high power density and are widely available. Unlike similar batteries in laptops, mobile phones, and other common devices, there are no charge controllers on the LiPo battery packs used (this saves weight). You will need a dedicated charger designed to monitor the charge of each cell in order to get the most out of your batteries.

	~~Transmitters may use alkaline, NiMH, or lithium-based batteries. Make sure you know what your transmitter requires, and have spares on hand and ready to go during competition~~.		== Safety ==
			See the Roger's Hobby Center page for more info (link above). Rules of thumb:

	~~== Series~~ and parallel ~~cells ==~~		* Use the right charger type (and settings)
			* Don't use parallel charging boards
			* Charge LiPo batteries in a fire-retardant LiPo bag
			* Discard damaged / puffy battery packs

			Do not extinguish a LiPo battery fire with water; place it in sand, in a metal container, or on concrete pavement far from flammable materials.

	Battery packs are ~~generally formed~~ of ~~more than one "~~cell". ~~These are put~~ in series ~~or occasionally parallel~~.		== Battery types (chemistry) ==
			Nearly all combat robots now run on lithium polymer (LiPo) battery packs just like those used in drones and other remote-controlled devices. They have very high power density and are widely available. Unlike similar batteries in laptops, mobile phones, and other common devices, there are no charge controllers on the LiPo battery packs used (this saves weight). You will need a dedicated charger designed to monitor the charge of each cell in order to get the most out of your batteries. Nominally each cell is 3.7 volts DC, but they can be wired in series (see below) for higher voltages.

	~~Series cells = more volts~~		Transmitters frequently use alkaline, NiMH, or lithium-based batteries. Make sure you know what your transmitter requires, and have spares on hand and ready to go during competition.
	~~Parallel cells = more amps~~

	~~Be careful with~~ series or parallel cells ~~- it~~ is usually better to buy a ready made pack with the correct number / size of cells.		== Series and parallel cells ==
			Battery packs are generally formed of more than one "cell". These are put in series or occasionally in parallel.
			*Series cells = more volts. For example: 2 LiPo cells in series (2S) makes a 7.4V battery. Three cells (a 3S battery pack) is 11.1V.
			*Parallel cells = more amps. Larger battery packs may have cells in both series and parallel for both higher voltage, and higher amps (current).
			It is usually better to buy a ready made pack with the correct number and size of cells. For larger bots, however, consider physically separated, redundant battery packs for increased survivability during combat.

	== How much capacity do I need? ==		== How much capacity do I need? ==
	Since keeping your robots weight down is always a high priority, you should only use as much battery as you need. One of the best tools for this was created by the legendary Steve Judd of Team Tentacle. His amp hour calculator helps determine how much battery you'll need for your robot's drive system. Team Run Amok hosts a [http://runamok.tech/RunAmok/TTT_example.html ~~version of the~~ calculator] over on their Ask Aaron site that you can use.		Since keeping your robots weight down is always a high priority, you should only use as much battery as you need. One of the best tools for this was created by the legendary Steve Judd of Team Tentacle. His amp-hour calculator helps determine how much battery you'll need for your robot's drive system. Team Run Amok hosts a version of the '''[http://runamok.tech/RunAmok/TTT_example.html Torque and Amp-Hour calculator]''' over on their Ask Aaron site that you can use.
	~~<br>~~
	Don't worry if the calculator doesn't list your chosen motor. You can still get a good estimate of how much capacity you need by typing in the proper voltage, weight, wheel speed and size into the calculator. The Ask Aaron site does a good job explaining how the calculator works.		Don't worry if the calculator doesn't list your chosen motor. You can still get a good estimate of how much capacity you need by typing in the proper voltage, weight, wheel speed and size into the calculator. The Ask Aaron site does a good job explaining how the calculator works. Once you've figured out what you need for your drive system, you'll need to also add in the capacity you'll need for your weapon system.
	~~<br>~~
	Once you've figured out what you need for your drive system, you'll need to also add in the capacity you'll need for your weapon system.
	~~<br>~~

	== Chargers ==		== Chargers ==
	[[File:LipoCharger.jpg\|thumb\|LiPo ~~Battery Charger~~]]		[[File:LipoCharger.jpg\|thumb\|Flexible battery charger for LiPo and other types]]

	~~Some older~~ chargers ~~could charge LiPo batteries without using a balance plug but doing this is not recommended~~. If the ~~cells within a pack become out~~ of ~~balance you run~~ the ~~risk of overcharging part of the battery. Also, some battery failures involve a single cell within a pack and a balanced~~ charge ~~will detect the problem~~.		There are a lot of options for chargers.
	~~<br>~~		*Make sure your charger works for the voltage and type of your batteries; for example, the common "C6D" type charger can only charge from 2S to 4S sizes.
	~~There are a lot of options for~~ chargers. Some ~~require~~ external 12v power supplies while others simply plug into an outlet. Although requiring an external power supply is inconvenient, it ~~typically~~ allows for faster charging. Some are limited to charging a single pack while others can charge multiple packs at the same time~~. Also, if you are running at higher voltages, make sure that your charge works for your batteries as some top out at 4 cells ~14.4v~~.		*Higher amperage batteries need more powerful chargers if rapid recharging is needed.
			*Some chargers need external 12v power supplies (ideal for outdoor/field events when connected to a car or truck for power), while others simply plug into a power outlet. Although requiring an external power supply is inconvenient, it allows for faster charging if its capacity is high enough.
			*Quality chargers connect to a battery's balance plug and monitor the voltages of cells in series, ensuring that one cell's voltage isn't much higher than another's. This will ensure maximum runtime for your bot and will warn you if one cell is failing. You should set aside a battery with a failing cell and not use it for competition. Poor quality chargers that don't check the voltage balance run the risk of overcharging part of the battery.
			*Some chargers are limited to charging a single battery pack, while others can charge multiple packs at the same time.

			== Connectors ==
			See the '''[[Connectors]]''' page to see some of the common types. Don't remove connectors from your batteries to save weight; it makes swapping and charging them challenging. Don't use any kind of reversible connector; you may start a fire if the wires are switched.

	== ~~Safety~~ ==		== Travel ==
			Keep LiPo batteries physically protected to avoid puncture, which can start a fire.
	~~See Roger's Hobby center (link above)~~. ~~Rules of thumb:~~

	* Use the right charger type (and settings)
	* Don't use parallel charging boards
	* Charge in a lipo bag
	* discard damaged / puffy packs

	~~== Connectors ==~~

	~~There are many connector~~ types ~~suitable~~ for ~~different robot weight classes~~. ~~Although some weight can~~ be ~~saved by soldering batteries directly to your electronics, it makes charging them challenging~~. ~~Check out the [[Connectors]] page to see~~ your ~~options~~.		If traveling by air with LiPo or other Lithium-based types, read and adhere to all aircraft safety regulations concerning these types of batteries. Here is the '''[https://www.faa.gov/newsroom/lithium-batteries-baggage FAA Summary]''' for the United States. As of 2019, LiPo batteries must be hand carried aboard. You should keep them in your LiPo charging bag for safety.

Chklnk: Rewrite in progress

2023-11-27T00:08:35Z

Rewrite in progress

← Older revision		Revision as of 00:08, 27 November 2023
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	[[File:Lipo_Battery.jpg\|thumb\|Lithium Polymer Battery]]		[[File:Lipo_Battery.jpg\|thumb\|Lithium Polymer Battery]]

	~~Almost all combat robots are powered by batteries.~~ Although compressed gas or internal combustion engines are occasionally used (especially for weapons), batteries are ~~always required~~.		Although compressed gas or internal combustion engines are occasionally used (especially for weapons), batteries are used throughout combat robots. There are too many batteries to choose from to make any meaningful list here, so we list some criteria to consider when choosing a battery.

	There are too many batteries to choose from to make any meaningful list here, so we list some criteria to consider when choosing a battery.

	[https://rogershobbycenter.com/lipoguide Roger's Hobby Center] has a really good guide to lipo batteries.		[https://rogershobbycenter.com/lipoguide Roger's Hobby Center] has a really good guide to lipo batteries.

	== Battery types (chemistry) ==		== Battery types (chemistry) ==
			Nearly all combat robots now run on lithium polymer (LiPo) battery packs. They have very high power density and are widely available. Unlike similar batteries in laptops, mobile phones, and other common devices, there are no charge controllers on the LiPo battery packs used (this saves weight). You will need a dedicated charger designed to monitor the charge of each cell in order to get the most out of your batteries.

	Nowadays (2021) nearly all combat robots run on lithium polymer (LiPo) battery packs. This is because they give the highest power density and are widely available. For safety, childrens' toy robots usually use ~~a different type~~, ~~generally~~ NiMH. ~~Transmitters often use other types~~.		Transmitters may use alkaline, NiMH, or lithium-based batteries. Make sure you know what your transmitter requires, and have spares on hand and ready to go during competition.

	== Series and parallel cells ==		== Series and parallel cells ==
Line 47:		Line 46:
	== Connectors ==		== Connectors ==

	There are many connector types ~~suitible~~ for different robot weight classes. Although some weight can be saved by soldering batteries directly to your electronics, it makes charging them challenging. Check out the [[Connectors]] page to see your options.		There are many connector types suitable for different robot weight classes. Although some weight can be saved by soldering batteries directly to your electronics, it makes charging them challenging. Check out the [[Connectors]] page to see your options.

User: Added some charger info

2021-11-13T18:50:05Z

Added some charger info

← Older revision		Revision as of 18:50, 13 November 2021
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	== Chargers ==		== Chargers ==
			[[File:LipoCharger.jpg\|thumb\|LiPo Battery Charger]]

			Some older chargers could charge LiPo batteries without using a balance plug but doing this is not recommended. If the cells within a pack become out of balance you run the risk of overcharging part of the battery. Also, some battery failures involve a single cell within a pack and a balanced charge will detect the problem.
			<br>
			There are a lot of options for chargers. Some require external 12v power supplies while others simply plug into an outlet. Although requiring an external power supply is inconvenient, it typically allows for faster charging. Some are limited to charging a single pack while others can charge multiple packs at the same time. Also, if you are running at higher voltages, make sure that your charge works for your batteries as some top out at 4 cells ~14.4v.


	== Safety ==		== Safety ==

User: /* Connectors */

2021-11-10T06:44:40Z

Connectors

← Older revision		Revision as of 06:44, 10 November 2021
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	== Connectors ==		== Connectors ==

	There are ~~too~~ many ~~annoying~~ connector types ~~which aren't compatible :) we could put a picture of~~ some of them ~~here~~.		There are many connector types suitible for different robot weight classes. Although some weight can be saved by soldering batteries directly to your electronics, it makes charging them challenging. Check out the [[Connectors]] page to see your options.

User: Added Battery Image

2021-08-06T02:29:46Z

Added Battery Image

← Older revision		Revision as of 02:29, 6 August 2021
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			[[File:Lipo_Battery.jpg\|thumb\|Lithium Polymer Battery]]

	Almost all combat robots are powered by batteries. Although compressed gas or internal combustion engines are occasionally used (especially for weapons), batteries are always required.		Almost all combat robots are powered by batteries. Although compressed gas or internal combustion engines are occasionally used (especially for weapons), batteries are always required.

User: /* How much capacity do I need? */

2021-08-05T20:06:53Z

How much capacity do I need?

← Older revision		Revision as of 20:06, 5 August 2021
Line 19:		Line 19:

	== How much capacity do I need? ==		== How much capacity do I need? ==
			Since keeping your robots weight down is always a high priority, you should only use as much battery as you need. One of the best tools for this was created by the legendary Steve Judd of Team Tentacle. His amp hour calculator helps determine how much battery you'll need for your robot's drive system. Team Run Amok hosts a [http://runamok.tech/RunAmok/TTT_example.html version of the calculator] over on their Ask Aaron site that you can use.
			<br>
			Don't worry if the calculator doesn't list your chosen motor. You can still get a good estimate of how much capacity you need by typing in the proper voltage, weight, wheel speed and size into the calculator. The Ask Aaron site does a good job explaining how the calculator works.
			<br>
			Once you've figured out what you need for your drive system, you'll need to also add in the capacity you'll need for your weapon system.
			<br>

	== Chargers ==		== Chargers ==

MarkR at 18:28, 5 August 2021

2021-08-05T18:28:48Z

← Older revision		Revision as of 18:28, 5 August 2021
Line 23:		Line 23:

	== Safety ==		== Safety ==

			See Roger's Hobby center (link above). Rules of thumb:

			* Use the right charger type (and settings)
			* Don't use parallel charging boards
			* Charge in a lipo bag
			* discard damaged / puffy packs

	== Connectors ==		== Connectors ==

	There are too many annoying connector types which aren't compatible :) we could put a picture of some of them here.		There are too many annoying connector types which aren't compatible :) we could put a picture of some of them here.

MarkR at 18:22, 5 August 2021

2021-08-05T18:22:18Z

← Older revision		Revision as of 18:22, 5 August 2021
Line 2:		Line 2:

	There are too many batteries to choose from to make any meaningful list here, so we list some criteria to consider when choosing a battery.		There are too many batteries to choose from to make any meaningful list here, so we list some criteria to consider when choosing a battery.

			[https://rogershobbycenter.com/lipoguide Roger's Hobby Center] has a really good guide to lipo batteries.

	== Battery types (chemistry) ==		== Battery types (chemistry) ==

MarkR at 18:06, 5 August 2021

2021-08-05T18:06:14Z

← Older revision		Revision as of 18:06, 5 August 2021
Line 4:		Line 4:

	== Battery types (chemistry) ==		== Battery types (chemistry) ==

			Nowadays (2021) nearly all combat robots run on lithium polymer (LiPo) battery packs. This is because they give the highest power density and are widely available. For safety, childrens' toy robots usually use a different type, generally NiMH. Transmitters often use other types.

	== Series and parallel cells ==		== Series and parallel cells ==

			Battery packs are generally formed of more than one "cell". These are put in series or occasionally parallel.

			Series cells = more volts
			Parallel cells = more amps

			Be careful with series or parallel cells - it is usually better to buy a ready made pack with the correct number / size of cells.

	== How much capacity do I need? ==		== How much capacity do I need? ==
Line 12:		Line 21:

	== Safety ==		== Safety ==

			== Connectors ==

			There are too many annoying connector types which aren't compatible :) we could put a picture of some of them here.