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--- electrical:12v:lifepo4_batteries_thread [2021/09/25 20:30]
frater_secessus [Suitability for RV use]
+++ electrical:12v:lifepo4_batteries_thread [2023/10/20 13:46]
princess_fluffypants [LiFePO4 characteristics]
@@ Line 7: / Line 7: @@
 ====== Synopsis of C&S LiFePO4 batteries thread ======
-The Cruisers and Sailing forum has a 300+ page [[http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069.html|LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks]] thread.
+This page is primarily for people interested in making their own lithium battery banks. This means buying raw cells (usually at a deep discount directly from a factory in China), and then putting together your own bank want with your own bus bars, chargers, Battery Monitoring System (BMS), and potentially things like bluetooth controllers and heaters.
+The advantage is potentially //massive// capacities for lower costs when compared to battery bank of [[electrical:12v:drop-in_lifepo4|drop-in lithium]] batteries. Going DIY also gives additional options in terms of different voltages and shapes of packs, which can be helpful for fitting them into weird places on RVs and vans.
+This is a fairly technical endeavor with a not insignificant risk of fire/explosion if you screw it up, so doing a lot of research beforehand is highly recommended.  And good place to start is the Cruisers and Sailing forum, which has a 300+ page [[http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069.html|LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks]] thread.
 There is gold in the thread but it can be hard to find.  This page attempts to distill the thread down to best practices for RV/campervan use of LiFePO4 batteries.  Links are provided so readers can go back to the thread for context-checking and critical examination.
+Another excellent resource is the [[https://diysolarforum.com/|DIY Solar Power forum]].
 ===== Suitability for RV use =====
 LiFePO4
-  * 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(([[https://img.mousetrap.net/misc/lithiumAbsorpTimes.jpg|higher charge rates can make a quasi-absorption useful]] to replace all the amps))
   * can use more nominal capacity than lead-acid (80-90% v. 50% [[electrical:depth_of_discharge|depth of discharge]])
   * are not damaged by [[electrical:12v:psoc|partial stage of charge]]
@@ Line 80: / Line 85: @@
 ==== LiFePO4 characteristics ====
-LiFePO4 are fully charged at 13.6v (3.4v/cell).((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-43.html#post1069816)) Voltage rises very quickly after LiFePO4 are fully charged (faster than the internal temps rise) so voltage can be used to assess full charge.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-45.html#post1096611))
+LiFePO4 (Lithium-Iron-Phosphate) are fully charged at 13.6v (3.4v/cell).((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-43.html#post1069816)) Voltage rises very quickly after LiFePO4 are fully charged (faster than the internal temps rise) so voltage can be used to assess full charge.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-45.html#post1096611))
 There is anecdotal evidence that sustained Vfloat at 13.8v (3.45v/cell) for months may not affect capacity.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-160.html#post1187410))
-LiFePO4 cells have a markedly lower full charge voltage than LiPo which is 3.7v.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-91.html#post1136613))  The LFP gives up energy density for stability and safety.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-93.html#post1137602))
+LiFePO4 cells have a markedly lower full charge voltage than LiPo (Lithium-Polymer) or LiIon (Lithium-Ion) which is 3.7v.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-91.html#post1136613))  The LFP gives up energy density for stability and safety.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-93.html#post1137602))
 Rated cycles will be easier to attain by going no lower than 80% DoD, 12.4v (3.10v/cell).((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-56.html#post1113745)) Shallower cycling may increase both cycles and lifetime capacity.((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-175.html#post1207749)),((http://www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069-177.html#post1231923))

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