Hello team,
I am wondering if there is any battery protection in the 18Ah, 15.6Ah, or 10Ah batteries at all.
Cheers,
J
Hi @johannv,
Our batteries do not have built in protection circuitry, if that is what you’re asking. The cells will not prevent themselves from being over-discharged, and there are not fuses built in that would prevent/reduce damage in the case of a short circuit. In effect they should be treated as a single large cell with a convenient connector.
Expected operation safety is reliant on monitoring the voltage (via telemetry and/or by setting up the battery failsafe in ArduSub). Additionally, our lithium-ion batteries (18/15.6 Ah) include a built in thermistor and connections to each group of parallel cells, that can optionally be monitored as an extra safety measure. Some people also choose to add fuses to various parts of their electronics.
It’s perhaps worth noting that having the power monitoring and safety features in the vehicle instead of in every battery means individual batteries are less protected when disconnected, but reduces the components required for protection when actually using batteries (since you can swap batteries without swapping fuses and management circuitry).
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Cheers Eliot.
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Hi,
Following this conversation, I’m well aware that there’s no protection for the batteries and that it might take significant room to have a proper protection in these currents. What about using a car fuse (80A for example) that shouldn’t take a lot of place and will at least give a general protection though not to each cell/column?
I have a client that had a couple of electric shorts due to water ingress into the main bluerov2 housing that caused part of the battery to extremely heat, melt the shrink and damage a few cells (as diagnosed by the balance charger). I’d like to add at least some basic protection in case these events will happen again.
I am wiring a custom ROV using two T200 thrusters and three T60 from China. It is a scaled up version of the CPS5 Drone ( CPSdrone – Making Underwater Drones ). I am using BlueRobotics tube and parts but their software. The body will be molded fiberglass.
It makes sense to me to place a main fuse at the battery to protect the battery and wiring, 60 or 80 amps comes to mind.
It makes even more sense to fuse each ESC so that if one shorts it will take its self out and the ROV can continue in emergency mode without going dead. I would guess 30 amps for each T200 and 15 or 20 amps for each T60s.
The signal power supply should have a 10 am fuse but if it blows the ROV goes dead, but it will anyway.
Has anyone else fused their BlueROV2 ? Where and how did you do it?
Has anyone experienced an ESC short?