I installed a temperature sensor on each battery in my boat house bank (4 sensors in total) and connected them to the temperature sensor inputs on CerboGX. Is there a way to make CerboGX report to DVCC the temperature of the HOTTEST sensor in this group for temperature compensation while charging? The reason behind this question: I am on a third set of Victron SuperCycle 170Ah batteries which randomly go into thermal runaway with no rhyme or reason. The installation was double-checked by two different Victron installers, the firmware is up to date, the settings on all devices triple triple-checked, and there is never overvoltage when charging according to the logs. Meanwhile, randomly while in absorption one of the batteries starts consuming increasingly more power, heats up, etc. After the battery cools down it might go through multiple charging cycles with no issues and then another battery exhibits the same behavior. And then another one. There is currently no way to give Multiplus an early warning since if the temperature sensor selected as active in DVCC is on the terminal of a nearby battery the overheating battery continues to heat up until it heats the battery with the active sensor at which point the damage has already been done.
How to Auto Select the HOTTEST Temp Sensor for DVCC (CerboGX)
- Thread starter rostyvyg
- Start date
sunshine_eggo
Happy Breffast!
Not to my knowledge. If you're a Node Red genius, you might be able to figure out a way.
When STS is enabled, you can specify the device to share, but if another temperature in the system goes higher, there's no way to switch to that one.
This is a battery problem, not a temperature problem.
Are these in series or parallel?
sunshine_eggo
Happy Breffast!
Is your charge voltage calibrated, i.e., have you confirmed the voltage reading the chargers are using is accurate?
Is your bank wired properly for parallel to share current?
Has anybody tried reducing absorption voltage .1V or .2V?
I have CerboGX networked to Multiplus, 2 x SmartSolar MPTT controllers, and BMV-712 with DVCC enabled and voltage, current and temperature readings shared having BMV-712 as a data source. The voltage reading on BMV-712 and reported to VE.Bus via DVCC is the same as measured by a multimeter directly on the battery terminals. The batteries have leads of equal length going to each battery from the negative and the positive bus bars. When I check the current going into each battery via clamp-on ammeter I see pretty much equal current on each positive lead. After the first set of batteries started overheating (and that happened 1 year after installation) I reduced the absorption charge voltage on MultiPlus and MPTTs from 14.7V to 14.5V. The second set of batteries started overheating pretty much after the same 12 months after they had been installed.
sunshine_eggo
Happy Breffast!
Yeah. not sure why I thought you would be relying on MPPT measured voltage in the context of a DVCC discussion... sorry about that.
It really sounds like batteries failing.
Some people poo-poo the little digital 12V battery testers, but the ones that actually report a mΩ (sometimes shown as "mR") value are VERY useful for comparison purposes. If you get 4mΩ on one battery consistently and 8mΩ on another battery consistently, you KNOW the 8mΩ battery is deteriorated. If you have something like that it might be useful to check each battery individually to identify a legit battery issue.
