Powering the Spectrum ST4 - Understanding Batteries

For those who are primarily shooting video, we highly recommend using VMount packs or Gold Mount Packs to power your spectrum.  Getting rid of an extra battery cord makes a huge difference for cable management.  If you really want to streamline, you can optionally put a large pack on the spectrum and the DTAP power to your compatible camera. 

For those with no batteries who want to shoot timelapse, for the money and the warranty, I think one of the best portable pack out there right now for the price is either the PowerAdd Pilot Pro 23000, or MaxOak 50000.  Both these packs are versatile, and have warranties, but do have a measurable failure rate  The packs don't have the full rated capacity as they likely overstate the cells capacity and have to massage the voltages which introduced loss to the system.

Power specs for the spectrum ST4

Input Voltage: 11.0-24.0 volts.
Current for the ST4 at rest (motors not energized):  0.1A to 0.2A based on back light setting
Current Requirements - 2.0 Amps , 3.5A preferred for high speed moves
Connector:  2.1mm x 5.5mm x 12mm circular barrel connector – center positive or VMount

Powering it from the wall 12V – use the 12V supplied adapter.  This comes with basic kits at is speced at 2.0 Amps 12.0 volts 100-240V 50/60Hz.  

Powering it from VMount - In Mid 2017 we started offering VMount plates on our spectrum.  The packs are typically outstanding in performance and power to weight ratios.  90% of the units we sell are outfitted with these plates.  The great thing about these packs is they have no step/up or step/down converters in them that have 10-25% loss right out of the gate.  These packs are efficient and rent-able in most parts of the world.  Getting into this type of battery system can be expensive.

Powering it from Gold Mount- In August 2018  we started offering Gold Mount plates on our spectrums.  The packs are typically outstanding in performance and power to weight ratios.  Just like with Vmount, the great thing about these packs is they have no step/up or step/down converters in them that have 10-25% loss right out of the gate.  These packs are efficient and rent-able in most parts of the world.  Getting into this type of battery system can be expensive.

For our mounts , we use either IDX P-V2, or Dynacore VMount Plates.
For Gold Mount plates we use Dynacore.  

Powering it from the wall 12V any old adapter that looks like it might work because, why not, what is the worst thing that could happen?  Just because it fits doesn’t mean it will work.   If you power it with a recycled supply from your old wifi router that says 12 volts/ 450mA – you aren’t feeding the rig enough current and the motion will suffer.   Worse yet if you plug in AC power or reverse polarity power, it will harm the ST4.  While we try to make the power handling robust and prevent permanent damage, damage from power problems is easily identified and not covered under warranty.  

Powering it from the wall 24V – pick up the optional  24V AC adapter from eMotimo.  It is speced at 3.75 Amps 24.0 volts 100-240V 50/60Hz.  It is great for powering turbo modes or long term in-studio work.  As we tune up the spectrum ST4, powering the rig at 24 volts from a strong supply will allow you to take advantage of the highest speeds and payloads the spectrum can provide.

Amp Hours, Watt Hours, mAH . . .understanding this should take a few milliHours!

Amp Hours (good for when you know voltage of the pack) - Let’s talk capacity. Batteries are rated with something called Amp-Hours (Ah) or milliamp hours (mAh).   Amp hours are valid when you know the voltage for which is was tested.  This is important and tricky as most portable lithium power packs are tested at 3.7 volts (what their cells are rated for).  A 12 volt 1.0 Amp-Hour battery theoretically will be able to provide 1 Amp at 12 volts for 1 hour. It would theoretically be able to provide 0.1Amps at 12Volts for 10 hours. For a fixed voltage battery, the math is simple – Capacity (AH) /Current (A)=Time (H).

Watt Hours - A more standard measure of energy is also a great place to start.  If a pack is rated for 100Watt Hours, it could put out 1 Watt of energy for 100 hours, or 100 Watts for 1 hour.  To convert from to and from Amp Hours, use the following formulas.  

• AmpHours x Voltage = Watt Hours
• (mAH/1000) x Voltage = Watt Hours 
• Watt Hours / Voltage = Amp Hours
• (Watt Hours / Voltage) *1000= mAH

Here some examples;