Danger Warning ACR's

[mitiempo]

Originally Posted by DanielI

Sorry, I meant a Victron Cyrix. Someone else told me about it on a different thread, so I assumed I was the only who didn’t know! And it would have been easier for others if I had actually called it by the right name.

https://www.victronenergy.com/batter...tery-combiners

Victron Cyrix combiners do not have a temperature sensor. They will shut down if they get excessively hot but it has nothing to do with battery protection.

https://www.victronenergy.com/upload...0A-230A-EN.pdf

[DanielI]

Originally Posted by mitiempo

Victron Cyrix combiners do not have a temperature sensor. They will shut down if they get excessively hot but it has nothing to do with battery protection.

https://www.victronenergy.com/upload...0A-230A-EN.pdf

Odd. I distinctly remember seeing something about conducting temperature through the brass connector bolt. I even remember thinking it sounded odd at the time. But all I can find is the following: “The Cyrix will disengage in case of excessive contact temperature,...” Perhaps I was misunderstanding what “contact temperature,” referred to? I assumed it meant the temperature of the terminals. Is that not right?

So the overload protection in a device like this would not have helped in the original case discussed in this thread? An actual temperature sensor would be necessary?

Thanks.

[mitiempo]

Originally Posted by DanielI

Odd. I distinctly remember seeing something about conducting temperature through the brass connector bolt. I even remember thinking it sounded odd at the time. But all I can find is the following: “The Cyrix will disengage in case of excessive contact temperature,...” Perhaps I was misunderstanding what “contact temperature,” referred to? I assumed it meant the temperature of the terminals. Is that not right?

So the overload protection in a device like this would not have helped in the original case discussed in this thread? An actual temperature sensor would be necessary?

Thanks.

It is just self protection - if it gets too hot it will shut down until it cools off.

For example the 120 amp Cyrix can handle 180 amps for 5 seconds and 120 amps continuously. If it is run over max rating for very long it will overheat and shut down until it cools off.

[smac999]

Any charging system would have blown up the battery. Nothing wrong with acrs.

[DanielI]

Originally Posted by smac999

Any charging system would have blown up the battery. Nothing wrong with acrs.

As I said initially, I’m not trying to re-ignite this debate; I think all parties made their points clearly upthread. I just wanted to understand the difference between a temperature sensor and what the Cyrix does, and what protections each provides.

What I’m coming away with here is that the Cyrix overload protection is more like a fuse, in the sense that, in the case described here, the unit could still pass enough amperage to cause the battery to melt down without reaching its overload level. (Similar to what someone wrote upthread about a fuse not blowing in this scenario.) Difference presumably being that a fuse would need to be replaced if it did blow, where as the Cyrix would shut down and restart once it cooled.

Is that correct?

Again, I’m just making sure I’m describing the intended operation correctly, not taking a position on whether such devices are “bad.”

[mitiempo]

Originally Posted by DanielI

As I said initially, I’m not trying to re-ignite this debate; I think all parties made their points clearly upthread. I just wanted to understand the difference between a temperature sensor and what the Cyrix does, and what protections each provides.

What I’m coming away with here is that the Cyrix overload protection is more like a fuse, in the sense that, in the case described here, the unit could still pass enough amperage to cause the battery to melt down without reaching its overload level. (Similar to what someone wrote upthread about a fuse not blowing in this scenario.) Difference presumably being that a fuse would need to be replaced if it did blow, where as the Cyrix would shut down and restart once it cooled.

Is that correct?

Again, I’m just making sure I’m describing the intended operation correctly, not taking a position on whether such devices are “bad.”

Any method of charging would have caused the battery to melt down. Temperature sensors on a battery, as posted by Andina Marie, would need to be on all cells, not just the post. For that matter if using an Echo Charge, which only passes up to 15 amps, the same could happen - it would just take longer.

It is very rare that a good battery will have a shorted cell and explode.

[YANDINA]

Originally Posted by DanielI

At the risk of reviving an old argument: I’m wondering how this would apply to the solar and Citrix combiner I’m installing.

As I understand it, the solar cannot produce enough amps to cause these types of problems itself. The Citrix combiner has a temperature sensor. So I’m not adding any risk, correct?

Also, the Citrix does its temperature sensing via the wires attached to the batteries. I looked at the literature, and it doesn’t say anything about the length of the wires, but I would think that the longer they are, the less effective this would be. Anyone know what the maximum wire run is?

Within reasonable limits, the wire length is not a factor. Voltage drop in the wire is AMPS x RESISTANCE. The resistance is constant but the amps tapers off to zero as the battery reaches full charge. Since the amps tapers to zero, the voltage drop tapers to zero and the final battery voltage is (nearly) identical to the voltage at the charger.