Lab Inventory: Batteries¶
Portable and mobile projects ultimately require mobile power supplies. This generally means a battery of some kind, although with the attendant concerns of regulation, control, replacement, and charging.
We typically try to develop projects as much as possible using reliable bench and wall power supplies, but systems perform differently on batteries, so systematic testing using batteries becomes essential.
The following tables may help you identify commonly used parts we have available in the lab supply. For a searchable index of all lab parts, please see Physical Computing Lab Inventory.
Battery Holders and NiMH Cells¶
We stock several types of holders for AA and AAA size battery cells along with rechargable NiMH batteries. The NiMH have a rated cell voltage of 1.2V; disposable alkaline batteries have a rated voltage of 1.5V.
Lab Part # |
Description |
|---|---|
AA rechargable battery (Amazon) |
|
AA alkaline battery (disposable) |
|
6 AA battery holder |
|
4 AA battery holder |
|
4 AA battery holder, panel mount |
|
AAA rechargable battery |
|
AAA alkaline battery (disposable) |
|
4 AAA battery holder |
We have several chargers for AA and AAA batteries, including:
9V Batteries¶
We stock a limited supply of rechargable 9V cells and 9V battery connectors. These are sometimes useful for components which require a higher operating voltage, but have significantly lower energy capacity than individual cells and so are not especially recommended for systems with motors or servos.
A 9V battery can directly power a microcontroller, but will incur significant energy loss when using linear 5V regulator. Please consider using one of the switching step-down regulators for more efficiency.
Lab Part # |
Description |
|---|---|
9V rechargable battery |
|
9V alkaline battery (disposable) |
|
9V battery clip, barrel plug |
|
9V battery clip, wire leads |
USB Power Banks (5V)¶
One of easiest ways to provide logic power to an Arduino or Raspberry Pi Pico is via a USB power bank, however, the lab does not normally provide these.
LiPo Packs¶
The lab used to stock several kinds of small LiPo battery packs and chargers. In general, these have safety risks regarding charging and puncture and are now discouraged. Please note that some specific Adafruit microcontrollers include 1S LiPo charging support. We do not normally use or provide these devices, but you may wish to consult Adafruit products and tutorials for easy-to-use LiPo options.
LiPo cells are nominally 3.7V, so battery voltages are rated in terms of the cell count. E.g., a low-power microcontroller might use a 1S single-cell LiPo at 3.7V, or a RC vehicle might use multiple cells in series to achieve higher voltage, available as high as 8S or 29.6V. For 12V motors, the best choice are 3S batteries with three cells in series. Note that this is a nominal voltage: a freshly charged LiPo cell can be as high as 4.2V, although it quickly drops during use.
Multi-cell packs use a single power connector which provides the series voltage along with a separate charging connector which provides access to the individual cell voltages. These require a specialized charger which can balance individual cells. The maximum discharge rate is specified as a multiple of the capacity: a 60C discharge rate on a 2.2Ah battery can support peak currents of 132 Amps, although self-heating prevents operating continuously at that rate. Recommended charge rates are 1C which will recharge in an hour. A common LiPo power connector is the XT60; some small quadrotor batteries use the smaller XT30.
The lab used to have the following:
Lab Part 2072: LiPo battery, 3S 11.1V 2200mAh, Turnigy Nano-Tech, 35~70C
Lab Part 2074: LiPo smart charger, Hobby King X200, 10A, 6S
12V Batteries¶
We have a limited supply of rechargeable 12V batteries. These are capable of significant energy delivery and useful for portable systems involving stepper motors, 12V gearmotors, or 12V LED systems.
12V/5V Lithium Ion Battery Pack¶
The first style is a self-contained Lithion-Ion power bank marketed for using with cameras and telescopes. The devices are fully packaged and relatively small so they can potentially be used in mobile or wearable devices. The outputs use regular USB and barrel plugs so these are relatively safe to use.
These come with a barrel plug Y-cable to connect a charger, battery, and an output load. Please return the cable with the battery.
These come with a specific charger which looks just like a wall-wart. Please keep the charger with the battery and do not return it to the regular power supply bins.
If the charger is missing it appears a regulated 12V supply will work.
We have a limited supply of the following:
TalentCell Rechargeable 6000 mAh 12V/5V Lithium Ion Battery Pack
includes 12V @ 3A barrel plug output
weight: 378 grams
includes 12.6V charger and Y-cable
Talentcell Rechargeable 3000 mAh 12V/5V Lithium ion Battery Pack
includes 12V @ 3A barrel plug output
weight: 180 grams
includes 12.6V charger and Y-cable
12V LiFePO4¶
The second style is a Lithium Iron Phosphate Battery (LiFePO4) normally marketed for use in solar power systems. Given the weight, this is more likely useful for portable rather than mobile systems. These require use of a specific charger, and some care to avoid short-circuits when wiring and handling.
We have several in stock which are rated at 10 Ah:
ECO-WORTHY 12.8V 10Ah Lithium LiFePO4 Deep Cycle Battery with 3000+ Cycles, Built-in BMS
weight: 2.46 lbs
Manufacturer: https://www.eco-worthy.com/
Maximum Charge or Discharge Current (1C): 20A
Terminal Style: F2 (silver-plated copper tabs, 0.25 inch wide)
These must be charged using the designated charger:
ECO-WORTHY 12V 5A Automatic Smart Battery Charger and Maintainer LCD Display for Lead Acid and Lithium (LiFePO4) Battery
Manufacturer: https://www.eco-worthy.com/
The battery terminals can connect with a F2 female crimp terminal:
UL Listed Red Female Spade Connector 22-16 AWG