Temperature Question re LFP Batteries
Mountain Don
Solar Expert Posts: 494 ✭✭✭
This is directed at those who are using LFP batteries....
In normal day to day use do the cells get warm? I am asking as if I was to use these I would need them inside to keep them above freezing in winter. However, we also have a warm 6 to 8 weeks in summer when I would not want them to add much / any heat to the interior. So that is the point of the question. Thanks
In normal day to day use do the cells get warm? I am asking as if I was to use these I would need them inside to keep them above freezing in winter. However, we also have a warm 6 to 8 weeks in summer when I would not want them to add much / any heat to the interior. So that is the point of the question. Thanks
Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
Comments
-
No mine don't get warm. I only use 20% of the capacity during a normal 10 hour stretch. There is heat produced by the inverter and charger but not from the batteries.8 kW Enphase micros AC coupled to a SolArk 12K
-
They don't add any additional heat especially in our application where we are what is called "Sub-C" (very low current relative to the ah capacity of the cells) because our bank is sized appropriately - not to mention insanely low internal resistance. Once you get above about .5 to 1C, then you may notice some. If you ARE doing that kind of charging, then you are using an EV and not a solar housebank.
-
From my battery monitor since I started monitoring power just over a month ago I have had around 74.1 kWh go into the battery, 67.9 kWh has come out and the battery has about 1.5 kWh more charge in it so have lost around 4.7 kWh in around 45 days or around 100Wh per day(4 Watts continuous) which I assume ends up as heat. Gives an overall battery efficiency of around 94%, this includes the power used to run the battery monitoring circuitry.
SimonOff-Grid with LFP (LiFePO4) battery, battery Installed April 2013
32x90Ah Winston cells 2p16s (48V), MPP Solar PIP5048MS 5kW Inverter/80A MPPT controller/60A charger, 1900W of Solar Panels
modified BMS based on TI bq769x0 cell monitors.
Homemade overall system monitoring and power management https://github.com/simat/BatteryMonitor
-
My batteries also don't feel warm to the touch. I generally limit global charging to 0.3C. Four FLEXmax 80's generate the heat (and noise) for my equipment room.
42 SP-335's (14.1kw) -> 4 FLEXmax 80's / 5kWh using 17 CA100 CALB cells / FLEXnet DC / MATE3 -> 2 Radian GS8048A and watched over by Vantage Pro 2+ PWS all running since 2015
Categories
- All Categories
- 222 Forum & Website
- 130 Solar Forum News and Announcements
- 1.3K Solar News, Reviews, & Product Announcements
- 189 Solar Information links & sources, event announcements
- 886 Solar Product Reviews & Opinions
- 254 Solar Skeptics, Hype, & Scams Corner
- 22.3K Solar Electric Power, Wind Power & Balance of System
- 3.5K General Solar Power Topics
- 6.7K Solar Beginners Corner
- 1K PV Installers Forum - NEC, Wiring, Installation
- 2K Advanced Solar Electric Technical Forum
- 5.5K Off Grid Solar & Battery Systems
- 424 Caravan, Recreational Vehicle, and Marine Power Systems
- 1.1K Grid Tie and Grid Interactive Systems
- 651 Solar Water Pumping
- 815 Wind Power Generation
- 621 Energy Use & Conservation
- 608 Discussion Forums/Café
- 302 In the Weeds--Member's Choice
- 74 Construction
- 124 New Battery Technologies
- 108 Old Battery Tech Discussions
- 3.8K Solar News - Automatic Feed
- 3.8K Solar Energy News RSS Feed