I see that the voltage rating on the new R3 can go to 26 volts. Will the T200 Thruster also handle 24 volts?
I presume that I would get more thrust with the higher voltage if that is permissible.
Hi @donoldham,
The T200 is designed to run best at 16V, and is rated to run well up to 20V. Beyond that, long term performance and durability has not been tested, though I can say at 27-28V there is imminent danger of overheating and burning out the thruster in minutes or less. Running beyond 20V will increase wear and significantly reduce efficiency, there will be some boost in thrust but most of the additional power will be wasted as heat. However, independent of the 26V rating of the Basic ESC, it has an approximately 30A constant current rating, depending on cooling. At 20V, the T200 draws about 30A constant, near the limit of the Basic ESCs capabilities. If you wish to run a T200 at beyond 20V at full throttle, you will need to use a different ESC with a higher current rating. If you limit thruster power to 600-650W or so by attenuating the throttle, it can be possible to use the Basic ESC and T200 at beyond 20V.
Running beyond the rated voltage of our thrusters does not instantly destroy them, but the rapidly diminishing returns in performance, increased wear, and drop in efficiency mean that we do not recommend doing this. The bottom line is the T200 is rated to run at 6-20V, and exceeding this against our recommendation can have mixed results, as well as void the warranty.
-Adam
1 Like
Adam,
Thanks for the clear reply. In larger battery sizes, such as 80 amp hour, or 100 amp hour, it is very hard to find anything but 12 volt or 24 volt batteries. There are no 16 volt options, making it an odd voltage in the larger battery world. I will work on getting an 18 volt battery in 100 amp hours, to get as close as possible to the ideal.
Don
It seems to me that a high current, DC to DC switching power supply would let you use those batteries.
You can buy them off the shelf, but see here for some background:
Agree that not optimising for a multiple of 12V seems an odd design choice. Anyone from BR care to share the design rationale behind this? Would be interesting to understand the reasoning as it does add complication that could seemingly have been easily avoided by optimising for 12V or 24V.
Thanks
Hi @YogurtyBull,
12 V is well within the operating limits of the T200, and it will run great at that voltage. It was originally intended to be nominally optimized for 12 V, but the final design ended up having more legs in terms of practical power density than expected, thus up to 20 V was deemed feasible for long term operation.
Additionally, since the T200 was originally designed for use with small marine vehicles such as ROVs and autonomous surface vessels, 16 V as the nominal recommended operating voltage ended up as the best balance given typical batteries used in those applications. These vehicles, given their smaller size and possible payload constraints, most often use high lithium ion or lithium polymer batteries which are commonly found in 4S configurations for hobbyist and similar use, essentially 16 V. These provide higher overall performance in terms of power and energy density.
-Adam
Thanks for the quick reply. Much appreciated.
Do you have any statistical failure stats for the T200? Looking to possibly use them on a transoceanic ASV and I’d like to understand typical failure modes and frequencies.
No problem!
Your second question is a bit more difficult to answer, as it is entirely dependent on the environmental operating conditions.
See here:
I would say to most common failure mode, when running the thrusters in sediment heavy conditions,
is abrasive and ferrous particles wearing away the protective coatings on the magnets, eventually causing corrosion.
My 20ah so called 12v lithium ion golf battery is at 16v straight off the charger.
Good afternoon! On YouTube, the author connected the T200 to a 24 volt battery. Approximately 600 watts. Works good.
https://www.youtube.com/watch?v=AzO50rwD9NQ
What about limiting the ESC PWM? If we use 24V, but we limit the PWM to let’s say 70%, would this also wear off the thruster? Is there a way to configure the ESC to step down or something similar? Since our system is already 24V and we intend to use multiple thrusters, a step down alone just for voltage reduction for the thrusters will be hard to find, since they would need to handle about 340A.
Hi @matosinho,
As above,
As far as I can tell (from the firmware manual included in the Technical Details section of the product page) the BLHeli_S firmware has no mechanism for reducing the total output voltage - I believe it only changes the frequency of the sinusoids it uses to drive the motor phases, not their amplitude (which would make some intuitive sense, because it’s supposed to be a speed controller, not a torque controller).
T200s weren’t designed for 24V systems, so there’s not a heap I can say here.
If you decide to go down the voltage regulation route then my main recommendations would be to use multiple regulators in parallel to be able to handle the required loads, and potentially look for high power components from automotive and/or industrial machinery applications, as they often need to handle large currents. It’s worth noting that there’s lower maximum power draw when using lower voltages, but that also reduces the maximum speed you can get out of each thruster.