2004Batteries/Power forum
Lithium-ion battery compatibility and power delivery issues with Arri 435 camera
22 years old. Gear and prices may have changed since.
What the thread found
- The original Arri 435 and 435 ES models draw an 18 ampere spike at startup that lithium-ion batteries cannot handle, while newer 435 models include a slow ramp option to address this issue.
- Pairing a nicad battery with lithium-ion batteries can solve the startup spike problem, with the nicad handling the initial power demand while lithium-ions run the camera during sustained operation.
- Lithium-ion batteries have higher internal resistance than nicad batteries, causing greater voltage drop under load and higher amperage draw.
- A small black button at the back of the 435 camera under the magazine port, when depressed by older Arri 3 magazines or 1000 foot mags, reduces the power spike and may improve battery performance with steadimag or 400 foot mags.
- Long extension cords and high-resistance sled wiring can cause voltage drops exceeding 2 volts, preventing the 435 from running properly since it requires minimum 22 volts to operate and at least 25 volts for high-speed filming up to 150 fps.
- Lithium-ion batteries can be safely wired in parallel without additional electronics, unlike nicad or nickel-metal hydride batteries which require diodes to prevent cross-discharge.
- When using parallel nicad or nickel-metal hydride batteries, diodes must be installed between cells to prevent the higher-voltage battery from discharging into the lower one, though this causes a voltage drop of 0.6 to 0.9 volts per battery.
- Lithium-ion batteries maintain consistent performance in cold weather conditions where nicad batteries experience degradation.
- During acceleration to high frame rates on the 435, voltage can drop significantly under load before stabilizing once the camera reaches operating speed.
Depends on
- The original solution involved specific battery models from several years ago that may no longer be available.
- Testing of lithium-ion performance was conducted without fully discharging batteries to verify behavior at 70% or 50% charge levels.
- The button depression trick for reducing power spikes was reported secondhand and had not been personally tested by the reporting party.
- Mixed results were reported when combining different battery chemistries, with one user experiencing shutdown of lithium-ion batteries in certain setups while another had success.
- The specific voltage requirements and spike characteristics may differ between individual 435 units or variants.
- Cold weather testing observations were anecdotal rather than systematic.