Hello all - I’m an electrical engineer excited about working on products and systems for the underwater robotics industry and I’m thinking of creating a system of smart batteries. In particular, I was thinking the BlueROV would really benefit from them. The current process for charging and working with the BlueROV batteries reminds me of the early days of drones when you had to use balance chargers and also kind of guess as to the State of Charge (SoC) of the battery, ending flights early, damage due to over discharging, etc. I’ve previously worked in the drone industry for 10 years and developed a series of batteries for drones and learned a ton!
The battery I would like to create would be a cutting edge smart battery with the following key features:
State of Charge (SoC) accuracy of 2% or better
Protections for under voltage (over discharge), over voltage (dangerous charge level), short circuit current, over/under temperature, etc
Charging via a standard USB C laptop power delivery charger
Rugged charging cable attached/detached without tools
Auto cell balancing internally
Sends status values back to the BlueROV navigator computer for display in QGC.
Internal heating system to allow the battery to run optimally in cold water
Deep rated (600m+)
I created a quick survey here to gather what specs the community would most like to use here:
I’ve also created a quick diagram to show the architecture:
Depending on specs, the battery might cost around $1K and the charger around $300.
I would really love to hear what the BlueROV community wants. Is this something you would find helpful? I would love to hear more about what features people really need and which they don’t and be able to come up with a super helpful solution. Thanks in advance!
I am always interested in new power solutions for the BR2 because I currently swap batteries more often than required due to the limited battery monitoring and protection available.
I have also experienced battery fires and overheating of the power distribution system, so safety is paramount!
Since the OEM batteries get the job done, would it be more cost-effective to create a new BMS that helps operators manage power and battery usage? In my circumstances, running the heavy version along transects in strong currents with DVL and UGPS requires careful power monitoring so this would be a feature I would like to see introduced.
It is good to see you working on different Wh ratings to help with logistics. Someone else was looking at parallel systems a while ago however this work seems to have fallen by the wayside.
Cost-benefits would also need to stack up. Surface power becomes the most effective solution if batteries become too expensive or operationally challenging.
Hey Jason, thanks for the info. Yeah I was considering just doing a add on BMS but I think there are a number of reasons it is better to just go with a full on battery:
Most important is safety. Having to periodically access the internal battery chamber to charge, with lots of exposed conductors is risky. If we added an external connector and BMS to the existing enclosure, the only difference is that you would be able to reuse some parts. Then you effectively have an end user assembled battery, with highly variable quality.
I also don’t think you could probably add a BMS with the features I am shooting for to the existing enclosure - there wouldn’t be quite enough space. My design relies upon high electro-mechanical integration to fit it in.
I think external quick disconnect connectors is also crucial. If you are cycling a critical seal (the battery enclosure O-ring) every charge then that increases the likelihood of failure over time.
I feel like surface power is not always the best option too. The cost of those Outland technology units is really high. $6200 top side unit + $2200 tether + $6400 vehicle side unit = $12800. So this battery setup could be an order of magnitude less expensive. If you need a very thin tether that could be an issue too. Or if you don’t have a generator.
Yes, I agree, opening the battery enclosure to replace batteries at sea creates a lot of risk that I would love to avoid.
Some members of the BR2 community (and other ROV manufacturers) have already created quick-change batteries and I often think about creating a similar system myself however I just never get around to doing it.
