I thought I was being safe when I spent the money for a Lithium battery with low temp charging protection. I now have a concern about the charge controller. Manuals for all charge controllers say that the battery must be connected first, then the solar panels. I was planning on leaving the panels connected, and letting the battery's BMS disconnect when the temperature is low to protect the battery. I now realize that the charge controller is not protected in this case. I have not seen a fix for this issue- so is it an issue? None of the system designs I have seen have a component to protect the charge controller. I am not sure what the behavior of the BMS is when the low temp protect is active- but is it different than the behavior when the battery is full? In either case, the output from the charge controller has nowhere to go.
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Protecting the charge controller with low temp charging cutoff LiFePO4 battery
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Originally posted by steveluannj View PostI thought I was being safe when I spent the money for a Lithium battery with low temp charging protection. I now have a concern about the charge controller. Manuals for all charge controllers say that the battery must be connected first, then the solar panels. I was planning on leaving the panels connected, and letting the battery's BMS disconnect when the temperature is low to protect the battery. I now realize that the charge controller is not protected in this case. I have not seen a fix for this issue- so is it an issue? None of the system designs I have seen have a component to protect the charge controller. I am not sure what the behavior of the BMS is when the low temp protect is active- but is it different than the behavior when the battery is full? In either case, the output from the charge controller has nowhere to go.Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.
Howard & Francine
2017 Ford F-350 DRW, '19 315RLTSPlus
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Originally posted by steveluannj View PostI thought I was being safe when I spent the money for a Lithium battery with low temp charging protection. I now have a concern about the charge controller. Manuals for all charge controllers say that the battery must be connected first, then the solar panels. I was planning on leaving the panels connected, and letting the battery's BMS disconnect when the temperature is low to protect the battery. I now realize that the charge controller is not protected in this case. I have not seen a fix for this issue- so is it an issue? None of the system designs I have seen have a component to protect the charge controller. I am not sure what the behavior of the BMS is when the low temp protect is active- but is it different than the behavior when the battery is full? In either case, the output from the charge controller has nowhere to go.
From the manual of the Victron controller I am getting....- Temperature sensing - the measured battery temperature is used by the chargers in the network for temperature compensated charging and in case of lithium battery for the low temperature cut off.
2019 Imagine 2400BH
2019 F150 XLT Super Crew, EcoBoost, 6.5' box, Max tow package with 3.55 ratio
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I contacted FSI about the same question - basically is the solar charge controller going to suffer if the BMS cuts off (or I physically remove) the batteries (two LiFePO4s). I was curious because the only place to remove current flowing to the batteries is a fuse between the controller and the batteries, not between the panel and the batteries. It was suggested I install a solar CB between the panel and the controller which I have since done. Purchased this and installed it between the panel and the controller.
This was really a safety measure should the temps dip so low that I would want to remove the batteries (not too frequent but we did hit -13F last year) even though I have battery heaters (which means very unlikely that I'll need to pull them). It's a manual CB but sufficient for my needs.
https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1
2022 Solitude 310GK-R - Dual pane, factory solar, factory gen, 8K axles with discs, W/D, Heat Pump, Gen 2 Goosebox, Battleborn
2020 Ram 3500 LB SRW 4WD Crew Laramie 6.7HO Aisin
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I think the bigger question is, what happens if you are in a cold weather location and the BMS disconnects the battery? A manual disconnect won't help because it might be the middle of the night when this happens.Rob, Betsy and Kali (Rhodesian Ridgeback)
2022 Solitude-S 2930RL
2023 GMC Sierra 3500HD Duramax Denali
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I am using the Victron controller and their temperature sensor, the sensor is mounted on top of the batteries on the A-Frame in a duel battery box. We got down to -40 and the BMS's shut down where I had no power to the rig. I emailed Lion Energy and they stated the BMS had shut down the batteries because of the cold, they do not have low temp shutdown, and once warned up they would wakeup, which they did. I only had the solar connected and just waited. Eventually everything came back online when it warmed up. I have my controller set to shutdown, not supply a charge at 34. So apparently it's nothing or I dodged a bullet. I just don't know. I just put my faith in Victron and all went well. Perhaps the batteries woke up around 32 and therefore in a sense, it was like the batteries being hooked up and then the controller came online at 34.Grand Design Imagine 2450RL 2020 born 7/2019
TV - 2007 Toyota Tundra 5.7 4X4 Limited w/Towing PKG under 30K miles, hanger queen until now
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Originally posted by rtrainer View PostI think the bigger question is, what happens if you are in a cold weather location and the BMS disconnects the battery? A manual disconnect won't help because it might be the middle of the night when this happens.2022 Solitude 310GK-R - Dual pane, factory solar, factory gen, 8K axles with discs, W/D, Heat Pump, Gen 2 Goosebox, Battleborn
2020 Ram 3500 LB SRW 4WD Crew Laramie 6.7HO Aisin
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Originally posted by BobinICT View PostI have my controller set to shutdown, not supply a charge at 34. So apparently it's nothing or I dodged a bullet. I just don't know. I just put my faith in Victron and all went well. Perhaps the batteries woke up around 32 and therefore in a sense, it was like the batteries being hooked up and then the controller came online at 34.2022 Solitude 310GK-R - Dual pane, factory solar, factory gen, 8K axles with discs, W/D, Heat Pump, Gen 2 Goosebox, Battleborn
2020 Ram 3500 LB SRW 4WD Crew Laramie 6.7HO Aisin
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Howson: The relay would still get power from either the converter or the charge controller, so that would not work. Perhaps a thermostatically controlled relay in the PV line. I already have a circuit breaker, so I can keep that open until I find a permanent solution.
I can't see the cold temp cutoff in the Victron information in the selling web page. Would all models do this? Seems like there should be a good, safe way to protect lithium batteries and the charge controller. Now I am wishing I bought a different battery and spent the savings on a new charge controller. :-(
2022 Reflection 280RS
2022 Silverado 2500 Duramax
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Originally posted by ajg617 View PostYou may have dodged a bullet. My understanding is that LiFePO4 cells can be permanently damaged in temps below approx -13F - at least that's what Battelborn has stated.Grand Design Imagine 2450RL 2020 born 7/2019
TV - 2007 Toyota Tundra 5.7 4X4 Limited w/Towing PKG under 30K miles, hanger queen until now
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Originally posted by BobinICT View Post
I apologize for my incorrect post. It was -40 wind chill. Sometimes things get fixated in my mind and I just remember it, was, cold. The lowest it got was -12 and that's when the batteries shutdown sometime between when I checked last, like the night before. The reply stated once the batteries warm up to over 32 and a charge is applied they would come back which they did.2022 Solitude 310GK-R - Dual pane, factory solar, factory gen, 8K axles with discs, W/D, Heat Pump, Gen 2 Goosebox, Battleborn
2020 Ram 3500 LB SRW 4WD Crew Laramie 6.7HO Aisin
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I checked the Renogy web site, and their information does say that the controller does handle the BMS shutting down the battery for overcurrent or undercharge conditions. I chatted with technical support, and they said that the controller should handle a low temperature cutoff as well, so I am not going to add anything to my system to disconnect the solar panels automatically. I will still probably pull the battery inside in winter, if only to secure it against theft. I won't do anything special while camping, for those occasional times when nighttime temps drop below freezing. That can happen any day of the year in the mountains.2022 Reflection 280RS
2022 Silverado 2500 Duramax
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Originally posted by rtrainer View PostPer the Victron Smart Solar MPPT manual2022 Reflection 280RS
2022 Silverado 2500 Duramax
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