I noticed that the old recommended battery that happens to also be acceptable for carry-on airplane travel seems to be discontinued. Does anyone have a new carry-on compatible battery suggestion? The old one was nice in that it seemed to be about the biggest battery with a rectangular cross-section that fit into the battery enclosure. Thanks!
Hi @skcolb,
We updated the BlueROV2 product page a few days ago with some more recent batteries that we have tested from two different suppliers:
- A 4S battery for the BlueROV2. Here are our recommendations:
Awesome, exactly what I was looking for. Thanks for pointing that out!
Kevin,
I want to make the battery pack (Lithiun-Ion 14.8V / 18Ah-R1 - 4S6P) of blue ROV
So, I’m looking to the picture showing of power wires (XT-90) and 5 wires (JST-XH) connections on the board. Can you help me about that ? you know where are the wire connections on the board ?
Thanks
Here’s a site that lets you configure a pack and see the balance leads: R/C Calculations
Only goes to 3s, but you can see what’s going on and extrapolate. I’ve built two packs from used tesla cells. Was a bit more work than I thought, but ended up costing ~$80ea, so it was a decent savings over two packs.
Hi
I have a 3S lipo 16000mAh 25C lipo battery with an EC5 connector.
Is it ok to use it for the BlueROV2 with EC5 to XT90 connector?
Hi @Vasanth, welcome to the forum 
We generally use 4S batteries (the higher voltage provides some extra thruster torque), but 3S is still comfortably within the operating range of our non-5V electronics, and 16Ah is a decent capacity. 25C discharge with 16Ah capacity allows for a current of 400A.
One of our T200 thrusters at the nominal 3S LiPo voltage of 11.1V would draw ~15.5A at maximum thrust (from the performance specifications on the product page). The standard configuration BlueROV2 has 6 thrusters, so 6 x 15.5A = 93A, which is well within that 400A limit. The BlueROV2 heavy configuration uses 8 thrusters, so 124A max, which is also well within that limit, with plenty to spare for powering the other electronics.
It’s worth noting that LiPo and LiIon batteries often have two discharge ratings - one for continuous discharge, and one for burst discharge (for periods under 10 seconds). If possible I’d recommend confirming that your 25C rating is continuous rather than burst, and if it’s not then you can do the same calculations for the actual continuous rating
If it turns out that your battery has a lower continuous rating than your thrusters would be expected to use at maximum thrust, you can likely still use it but you’ll likely need to look into limiting the thrust output.
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Thank you so much for your response.
I’m also planning to build a custom Li-ion battery.
I have a few LG INR18650 3200mAh (3c) LI-ION battery stock.
So if the 3C rate is enough, then I’m planning to buy some more cells for
14.8v, 16Ah, 3C(Continuous), 4S5P configuration.
16Ah at 3C is 48A continuous discharge. At 14.8V a single T200 thruster uses ~22A at max throttle, so if you’re using a configuration with more than 2 thrusters you’ll likely want to limit the thrust output.
Note that higher voltage uses higher maximum current, but also produces higher thrust. A T200 controlled by a BasicESC and powered with 14.8V would produce roughly equivalent forward thrust from an 1808us pulse duration input signal as it would from a 1900us pulse duration when powered with 11.1V, and would use more like 12A to do so (instead of the 15.5A with the 11.1V supply).
That said, 48A discharge is still significantly lower than the 93A that would be drawn on the LiPo battery (and that’s not accounting for the other electronics, like lights, the onboard computer, and the flight controller), so while the LiIon would last longer than the LiPo, the vehicle would need to go quite a lot slower.
I actually tried to custom build a similar like Bluerobotics lithium battery for blueROV2.
As bluerobotics battery specs is 14.8V, 15.6Ah, Continuous discharge - 60A(3.8C).
Indeed, and our discharging information states
If you’re planning to keep any high throttle usage to short bursts then you likely don’t need to apply thrust limiting, but limiting can be helpful for making sure that the power usage definitely stays within the operating capabilities of the battery, which can give some extra peace of mind.
The vehicle won’t immediately be permanently damaged if you briefly try to draw more current than the battery can provide, but if that occurs the vehicle will be underpowered and the Companion computer will likely restart itself, which can potentially be problematic if you’re doing anything important, or operating in strong currents (since you lose telemetry and the video feed, and the thrusters shut off).
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