I am surprised that vans/RV's don't have to have a quick disconnect switch
to disable the batteries when they are either overheating or worse, beginning to
burn up.
Compulsory on a boat, but in a van where the batteries could be difficult to
access (maybe under the bed) there's no way to quickly shut down a miscreant battery
before it's too late.
The scooters demonstrate how quickly it can happen.
Whenarewethere said
07:37 PM Feb 14, 2023
It would be a very good safety feature. Also from an inverter issue, let alone batteries themselves.
I carry a pair of parrot cutters, but usually not in a readily accessible location. I might rethink location.
Mamil said
08:43 PM Feb 14, 2023
The regs do have a requirement for automatic disconnection of supply in the case of a fault:-
Clause 5.4.7.1 Protection Device: Batteries and associated wiring shall be protected against overload and short circuit by means of fuses or circuit breakers in each unearthed pole. Protection devices shall be accessible, protected against accidental damage, and installed in one of the following locations- a) within 200mm of the battery terminals, or b) directly outside the battery compartment, or c) 1m from the battery terminals, provided each conductor is contained within a protective covering such as sheathing, conduit, or cable trunking for its entire length from battery terminals to the circuit protection device
Meanwhile a switch is usually for isolation, ie to disconnect the batteries for storage or servicing, not to protect in event of a fault.
It is of course good practice to have both.
Note also that it says that protection device should be in "each unearthed pole" so that means in an isolated system (as in most caravans), there should be a fuse/circuit breaker in both positive and negative battery cables.
TimTim said
09:59 PM Feb 14, 2023
The Li ion batteries in scooters, phones etc. are a different chemistry to the LiFePO4 that we use. There has never been a fire with LiFePO4 but they can swell up and vent nasty substances when over charged or over discharged but to get to that stage you will have needed a failure in your BMS and/or a failure in your charger, whether it be a dc to dc charger or a solar controller.
By old bus / motorhome had a 50mm piece of lead as a fuse off the main supply . 50mm long X20mm I guess 4mm thick . Fuso. Older vehicles had a disable wire we wouldnt really know it was a protection wire, fuse .
Brodie Allen said
09:06 AM Feb 15, 2023
An over-temperature warning device might also be helpful in detecting
rising temperatures in the batts in time to avert a tragedy.
Mamil said
07:52 PM Feb 15, 2023
Brodie Allen wrote:
An over-temperature warning device might also be helpful in detecting rising temperatures in the batts in time to avert a tragedy.
If you're talking about Lithium, then the regulations require not just a warning device, but also automatic disconnection of the battery...
Clause 5.4.12.3 Lithium Ion Batteries, Battery Safety System: Each lithium ion battery pack shall be protected with a battery management safety system either integrated into a battery pack or as a separate component. The battery management safety system shall continuously monitor the voltage, current and temperature of the battery and protect against the following by automatic disconnection - a) over and under voltage, and b) over and under temperature, and c) over current
These functions are usually performed by the Lithium battery's BMS. Lead acid batteries have no such requirements.
Of course, having it in the regulations is one thing, people following the regulations is quite another. It doesn't help that the electrical regulations tend to lag the technology available by a good few years, and new rules are not applied retrospectively.
-- Edited by Mamil on Wednesday 15th of February 2023 08:03:20 PM
I am surprised that vans/RV's don't have to have a quick disconnect switch
to disable the batteries when they are either overheating or worse, beginning to
burn up.
Compulsory on a boat, but in a van where the batteries could be difficult to
access (maybe under the bed) there's no way to quickly shut down a miscreant battery
before it's too late.
The scooters demonstrate how quickly it can happen.
It would be a very good safety feature. Also from an inverter issue, let alone batteries themselves.
I carry a pair of parrot cutters, but usually not in a readily accessible location. I might rethink location.
The regs do have a requirement for automatic disconnection of supply in the case of a fault:-
Meanwhile a switch is usually for isolation, ie to disconnect the batteries for storage or servicing, not to protect in event of a fault.
It is of course good practice to have both.
Note also that it says that protection device should be in "each unearthed pole" so that means in an isolated system (as in most caravans), there should be a fuse/circuit breaker in both positive and negative battery cables.
The Li ion batteries in scooters, phones etc. are a different chemistry to the LiFePO4 that we use. There has never been a fire with LiFePO4 but they can swell up and vent nasty substances when over charged or over discharged but to get to that stage you will have needed a failure in your BMS and/or a failure in your charger, whether it be a dc to dc charger or a solar controller.
https://www.youtube.com/watch?v=yiOljillLRY
This second video has no relevance and a word of warning Please do not try this.
https://www.youtube.com/watch?v=07BS6QY3wI8
LiFePO4 is very safe
.
rising temperatures in the batts in time to avert a tragedy.
If you're talking about Lithium, then the regulations require not just a warning device, but also automatic disconnection of the battery...
These functions are usually performed by the Lithium battery's BMS. Lead acid batteries have no such requirements.
Of course, having it in the regulations is one thing, people following the regulations is quite another. It doesn't help that the electrical regulations tend to lag the technology available by a good few years, and new rules are not applied retrospectively.
-- Edited by Mamil on Wednesday 15th of February 2023 08:03:20 PM