Do I have humidity issues in the battery room?

[totalconfusion]

The humidity seems high. How will this effect battery life?

I've been logging temperature and humidity for a short while on a new LiFePO4 installation

The Pylontech batteries are in an open frame rack. Everything is in a small room protected from direct sunlight and there's a fan running constantly pushing OUT, so as to induce air flow by creating negative pressure

I was considering hooking up the fan to the temperature sensor in the Cerbo and to have the fan only turn on after say 25 Celsius. Is there really any point in doing so? I guess you'd get more life out of the fan and save a small amount of electricity?

It's the Australian outback. Here is the data.

 

[seneysolar]

Not unless you are getting condensation. Then you just have corrosion to worry about.

 

[green mountain boys]

As temperature falls, relative humidity will increase.
As temperature rises, relative humidity will decrease.

If the humidity is coming from outside you can lower the relative humidity inside by allowing the air to warm up inside. So long as it does not get too hot for your components.

Does the exhaust fan have a place for air to enter? The fan will be much more effective if air can freely enter.

At night, when the air cools, is probably when you will have the biggest problem with humidity. Try to not let the temperature inside fall too much at night.

 

[LydMekk]

76% is way over a normal indoor room. Those are around 30-40%.
Install a dehumidifier which should be run at all times and emptied.

 

[rin67630]

Not unless you are getting condensation. Then you just have corrosion to worry about.

Usually, condensation does not happen in ventilated a room, where energy is dissipated.

 

[seneysolar]

Usually, condensation does not happen in ventilated a room, where energy is dissipated.

Right, i guess my point is the batteries dont care about humidity until you get condensation. Large temp swings like overnight, may get condensation on the outside of the batteries the next day while they will still be cool and the air warms up faster. If thats not happening, i wouldn't be concerned.

76% is way over a normal indoor room. Those are around 30-40%.
Install a dehumidifier which should be run at all times and emptied.

No way would i run a dehumidifier all the time- Waste of power. 70% humidity is just a normal summer day outside.

 

[Solar Guppy]

Put the equipment in a controlled environment is what I do, all of mine runs in an area with a mini-split heat pump. The cost and energy usage is small compared to the risk of running in an open to the outdoors environment. More airflow won't do anything positive.

 

[rin67630]

Right, i guess my point is the batteries dont care about humidity until you get condensation. Large temp swings like overnight, may get condensation on the outside of the batteries the next day while they will still be cool and the air warms up faster. If thats not happening, i wouldn't be concerned.

Maybe reduce ventilation overnight, so that the batteries would not cool down that much??

 

[totalconfusion]

I guess the energy consumption used to regulate the temperature depends on the capacity of the system. For a full off grid over paneled house, it'd be a no brainer. For an RV/system with limited capacity, probably not.

I was having a chat with someone on DIYSolar recently about what does more damage to batteries. Absolute temperatures vs constant thermal cycling between temperatures. They were of the opinion that the only thing that realistically mattered was the absolute temperatures.

I'm just trying to get a handle on what's a normal humidity for an enclosed room. I understand that it's very much got to do with the climate of where you live, but 70%+ just seems high for outback Australia.

I'm not getting any condensation at all, if I were I'd be really concerned. The air intake is the gap underneath the door. I thought a negative pressure inside the room would be more than enough to bring fresh air in. I could install a vent at the bottom of the door, but I'm not convinced poor airflow is the issue.