question

Hi Tim.

I have also posted this question in the past (with zero answers) and was about to post it again.

I have exactly the same problem with mine, which also follows a pretty much "by the book" installation with all victron gear. Have you ever done any data logging on the control input from the BMS to confirm that it isn't the BMS dropping the signal? I have a data logging multimeter here, so might have a go with that.

I haven't payed too much attention to the issue, seeing as in my case it's more of an annoyance than a major problem. I might eventually switch to a battery protect as an alternative.

Regards,

Justin

Another piece of info that may help, that 60 minute interval starts at the time that the LiCharge turns on. E.g. my solar started producing power at 6:22 this morning, the LiCharge has dropped out at 7:22 and 8:22.

Mine too! Just completed the build for my Sprinter van, using all Victron components/batteries. I also used the LiCharge Cyrix. The double click relay trips out for a few seconds exactly every hour, whether or not the inverter is on or off, night or day. Everything operates perfetly with no problems, and I have monitored both the Touch 50 display and the BMV 712 monitor chassis/starter battery during this every hour event, and neither of the displays show any indication of any voltage/amp spike/drop when it occurs. I have only just begun to track this down, and tomorrow I'll will confirm it is the Cyrix.

I think I may have this situation figured out. Victron makes 3 different Cyrix battery protect devices. Tim (above) has the same Cyrix I have, which is the Cyrix Li Charge. Here is a quote from the Victron Cyrix datasheet:

'Cyrix-Li-Charge The Cyrix-Li-Charge will connect a battery charger with 3 seconds delay: - if the charge disconnect output of the VE.Bus BMS is high, and - if it senses 13,0 V (resp. 26,0 V or 52,0 V) or more on its battery charger connection terminal, and - if it senses 2 V or more on its battery terminal (the Cyrix will remain open if not connect to the battery). The Cyrix-Li-Charge will disengage immediately whenever its control input becomes free floating, signalling cell over voltage or cell over temperature. In general, a cell over voltage alarm will reset shortly after charging has been stopped. The Cyrix will then reconnect the charger after a delay 3 seconds When the Cyrix-Li-Charge is engaged (charger connected to battery) it will disengage after 1 hour to check if the charger is still enabled.. If, after the Cyrix has disengaged, the output of the battery charger immediately increases to 13,0 V or more, the Cyrix will reengage, with a 3 seconds delay.'

The Cyrix Li Charge datasheet schematic shows it connected to a standalone charger. I wonder if the trickle charger I have on the starter battery would cause the starter battery to read >13.0 volts, causing the Cyrix to re-engage every hour. It makes sense, and I will do some further diagnosis on the van. I believe the Cyrix model that is needed to eliminate the one hour relay disengagement would be the Cyrix Li Ct.

After some testing, I found even if I remove the trickle charger on the starter battery, it will still do it's every hour double click. In my searching, a came across a Victron schematic showing a Smart Battery Protect in place of a Cyrix device. And this, in response to my question posed to Peter Kennedy of PKYS, of the double clicking Cyrix-Li-Charge:

Old post, but for anyone thinking of this.

There's another problem with the schematic above. The batteries are wired in series for 24V. They charge in series at 24V. So far OK.

There are two separate 12V busbars one for each battery. So unless by chance there's always an exactly equal load on each of the 12V busbars, the batteries will become badly out of balance very quickly. Net result is one battery is going to become fully discharged. And disconnect, killing one 12V leg and the 24V leg. A battery balancer probably won't help either.

I don't see how the cyrix can do anything here.

Net result is... If you want 12V from a 24V system, use a 24:12 DC:DC converter. And fit a balancer. But never take a load from only one of the batteries.