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electrical:12v:lifepo4_batteries_thread [2017/12/09 17:52] frater_secessus |
electrical:12v:lifepo4_batteries_thread [2021/09/25 20:30] frater_secessus [Suitability for RV use] |
* can take full current during charging; there are no //stages// in the lead-acid sense | * can take full current during charging; there are no //stages// in the lead-acid sense |
* can use more nominal capacity than lead-acid (80-90% v. 50% [[electrical:depth_of_discharge|depth of discharge]]) | * can use more nominal capacity than lead-acid (80-90% v. 50% [[electrical:depth_of_discharge|depth of discharge]]) |
* are not damaged by low SoC | * are not damaged by [[electrical:12v:psoc|partial stage of charge]] |
* can be mounted vertically or on a thin edge (but not flat)((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-234.html#post1452743)) | * can be mounted vertically or on a thin edge (but not flat)((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-234.html#post1452743)) |
* smaller and lighter than like-capacity LA | * smaller and lighter than like-capacity LA |
==== LiFePO4 charging for RVs: running barefoot ==== | ==== LiFePO4 charging for RVs: running barefoot ==== |
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Although his setup does not use it, T1 Terry describes a "middle 80%" approach that works well with Fractional C systems. It can eliminate the need for [[electrical:12v:BMS|BMS]] balancing: | T1 Terry describes a gentle, relatively low-tech approach that can work well with vandweller use patterns. It does not use a [[electrical:12v:BMS|BMS]], judging that in a vandwellers' use the BMS introduces more hazards than it alleviates. This approach: |
* starts with a balanced battery when installing. | |
| * starts with a balanced battery |
* uses moderate terminal voltage (13.8v) to gently rebalance cells((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-77.html#post1132126)),((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-44.html#post1096480)), and even become more balanced over time.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-109.html#post1142675)) If they do get out of balance for some reason, run more conservative SoC voltages until they can be manually rebalanced.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-294.html#post1779359)) | * uses moderate terminal voltage (13.8v) to gently rebalance cells((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-77.html#post1132126)),((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-44.html#post1096480)), and even become more balanced over time.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-109.html#post1142675)) If they do get out of balance for some reason, run more conservative SoC voltages until they can be manually rebalanced.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-294.html#post1779359)) |
* charges at less than 1C, common in solar charging | * charges and discharges at less than [[electrical:12v:battery_capacity|1C]], common in solar charging. i.e. less than 100A with a 100Ah bank. |
* keeps the voltage "between the [voltage] knees", 13.8v - 11.8v.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-103.html#post1140470)) This is also called the "middle 80%". | * keeps the voltage "between the [voltage] knees", 13.8v - 11.8v.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-103.html#post1140470)) This is also called the "middle 80%". |
* does not //require// strapping((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-59.html#post1118000)) although it is a recommended best practice((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-253.html#post1574064)) | * does not require strapping((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-59.html#post1118000)) although it is a recommended best practice((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-253.html#post1574064)) |
* no BMS required ("running barefoot") | |
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Since the defining feature of this approach is the lack of BMS, it will be referred to as "barefoot" on this page. | Since the defining feature of this approach is the lack of BMS, it will be referred to as "barefoot" on this page. |