ECPC 12v 400Ah Temperature Constraints?

[lpedrazzi]

I was so excited to see Will's video recommending these highly; just phenomenal that I can now get 400Ah LiFePo for what 200Ah of Battle Borns cost me 2 years ago. That said, I was surprised to see the following blurb in their specs:

Surrounded working condition temperature: Charge: 41 ~ 113°F (5 ~ 45°C); Discharge: -4 ~ 131°F (-20 ~ 55°C) (Suggested for charging: 50 ~ 104°F (10 ~ 40°C); Suggested for discharging: 14 ~ 113°F (-10 ~ 45°C) (https://www.electriccarpartscompany.com/12v-400ah-preferred-lifepo4-lithium-battery-packs)


This floored me... I understand the low temp limitations of LiFePo, but had never heard of issues with charging or discharging at temps of 104F. Cars in the sun routinely get that hot! Battle Born specs allow charging / discharging up to 135 degrees F, so I'm assuming this is a prismatic VS cylindrical issue?

I've just sent a note to ECPC to ask what kind of damage I'd be doing by routinely charging at or near the 104 degree ceiling they are suggesting, but I thought I'd post here since I haven't seen it brought up. I'm hoping this is just a typo... I was so excited to upgrade

 

[chrisski]

I'm going to start with I don't have a good answer for you.

I am getting a 580 ah 24 volt 16 cell lithium pack I am putting together. I have the some constraints you mentioned. Have not built the battery, but charging at 90 degrees today, my FLA pack reached 104 F. So, I don't know what will happen.

For me, I may remove the two 24 volt batteries I make from my RV in the Summer. In Arizona, temps can typically reach 110 in the summer, and sometimes 120. I don't RV in the summer, so may just pull the batteries during those four tough months.

If I go on a trip, I would need to reinstall, but still the batteries are in pass through storage, which would still hit whatever temps are outside. If I get to a point where I want to run Air conditioning, I will need to move my batteries and inverter inside.

I'm a little leery about pushing things to their limit consistently especially high dollar items like these batteries.

This chart is from the Eve cells I'm purchasing and says Half the cycles at 45 degrees Celsius compared to 25 degrees Celsius. I imagine all lithiums last less when discharged hotter.

 

[lpedrazzi]

Glad to know I’m not alone! I hear so much about low temperature concerns, I’m really surprised to see the charging limitations on the high-temperature side, given the popularity in the van conversion market. 105 seems incredibly low. Easy to reach that on even a mildly hot day in a van.





I’ve now been obsessively looking at spec sheets for all the various batteries. Not all of them specify a “charge temp range”, which is the stat that most concerned me about the ECPC battery, but those that do are often in agreement… 105-115 being the most frequent recommended limit. 105 degree temps parked in the sun is basically 90% of the year here in Southern California, so if I can’t charge my batteries from my panels in those conditions, I may as well scrap them





Waiting on a call back from ECPC to hopefully learn more about this.

 

[lpedrazzi]

Spoke to ECPC on the phone... wow what a difference from talking to Battle Born. I just wanted to know if I'm going to be damaging these batteries if they are getting a small (~20 amp) current from my solar array while parked in the desert heat. Lots of ummmmms and uhhhhhs, followed by a "we put these in lots of van conversions, so it should be fine." Not very reassuring for a $2200 purchase.

 

[chrisski]

Spoke to ECPC on the phone... wow what a difference from talking to Battle Born. I just wanted to know if I'm going to be damaging these batteries if they are getting a small (~20 amp) current from my solar array while parked in the desert heat. Lots of ummmmms and uhhhhhs, followed by a "we put these in lots of van conversions, so it should be fine." Not very reassuring for a $2200 purchase.

Sometimes I think these people in the battery companies have their product because they did a request for proposal or had a product branded with their company logo just hoping to push these products out a cheaper rate than Battleborn and hoping to make money, but are totally unprepared to deal with issues like you said, performance questions.

Even when testing was done at the original facility to develop battery specs, I wonder how many batteries were sacrificed to get a reliable chart as compared to adding so and so an element to the mixture should make the min charge temp go so much lower with an educated guess. I'm afraid to pull back the curtain on some of these things to find the truth. I would not be surprised if a test about 20 amp charge rate effecting that battery has never been done.

$2400 will get you 16 Eve 280 ah cells delivered to your door in the states, which is the equivalent of about 7 or 8 battleborn batteries. All you'd have to do is wire them, put a BMS on each battery, and build a plywood enclosure, and you have your own battery.

 

[Bradlud]

Spoke to ECPC on the phone... wow what a difference from talking to Battle Born. I just wanted to know if I'm going to be damaging these batteries if they are getting a small (~20 amp) current from my solar array while parked in the desert heat. Lots of ummmmms and uhhhhhs, followed by a "we put these in lots of van conversions, so it should be fine." Not very reassuring for a $2200 purchase.

Hi!

The manual gives recommended charge/ discharge temps that you listed above, which take amperage into account. Higher current = more heat. These packs come in a IP66 rated case with no fan, so there is a potential for heat buildup depending on the current. The small, 20 amp current should not cause any problems. The BMS does have high and low temperature cutoff, which will keep the cells safe. As long as no cell reaches 158 degrees, you will not damage the pack due to heat.

In the "Battery care and maintenance" section, it says: "The Li-ion cell will be permanently damaged if the internal temperature gets too high (over 70℃, or 158°F). For this reason, do not continuously charge or discharge the battery pack with a high current if the surrounding temperature is really high, or else the battery cycle life and performance will be dramatically reduced."

Hope this helps!