User Guide

Lynxmotion SSC-32U Servo Controller Board

Electronics Guide

Battery Chemistry & Current

Alkaline

Alkaline batteries are most commonly found as single cell 9V, AAA, AA, C and D. These

batteries are not rechargeable and are usually 1.5V. You can use four 1.5V cells to make a 6V

battery pack. The battery’s capacity is rarely indicated on the cells, so it is difficult to gauge just

how long they will last. If the battery is inexpensive, you can assume it will not last for long. The

discharge rate (how much current the battery can provide either in bursts or continuously) is

also rarely ever indicated. As such, if you are using several servos and notice that they do not

have enough power, your batteries are likely the cause.

NiMh / NiCd

NiMh and NiCd are normally found as AA, AAA cells or as battery packs. These can be

recharged and are currently the most popular type of battery for mobile robots (aside from

humanoids) because of their weight and price. NiMh are preferable to NiCd because they can

be recharged to full capacity every time, whereas if you recharge NiCd batteries which are only

partially used, they will lose some of their capacity each time. Single cell batteries usually

provide 1.2V, and as such, to make a 6V battery pack you would need 5 cells. The capacity of

each cell is almost always indicated on the cell. The discharge rate tends to be 1C or 2C for

most Nickel based batteries. The ‘C’ rating is in relation to the capacity. If a cell is rated at

2800mAh, 1C=2800mA. For example, a 1.2V 2000mAh NiMh cell rated at 1C can discharge at

2.0A continuously. Using five such batteries means you would be able to provide 6V at 2A

(continuously). Battery suppliers / manufacturers create packs of several cells to provide higher

voltages, and add a custom connector.

Lithium

LiPo / LiFe etc tend to be found as flat cells or rectangular packs and are normally found as

multiples of 3.7V. Lithium batteries have the advantage of being lighter weight than NiMh and

capable of providing significantly higher discharge rates (10C, 20C or even higher).

Unfortunately for R/C servos, 3.7V is too low, whereas 7.4V is (usually) too high. We suggest

using LiPo for high voltage servos only.

Lead Acid

Lead acid batteries are normally 6V, 12V and 24V though many other options are possible. This

is the kind of battery you would normally find in a gasoline powered vehicle. A 6V lead acid

battery pack can normally provide enough current to power many R/C servos, but the battery

itself will be quite heavy.

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