Both sides previous revision
Previous revision
Next revision
|
Previous revision
Next revision
Both sides next revision
|
electrical:12v:deep_cycle_battery [2018/12/06 11:25] frater_secessus [carbon FLA] |
electrical:12v:deep_cycle_battery [2018/12/28 14:29] frater_secessus [Non-LiFePO4 lithium-ion] |
This type of VRLA battery gelatinizes the electrolyte to stabilize it. While renowned for their duty cycles, they are rarely used in campers. | This type of VRLA battery gelatinizes the electrolyte to stabilize it. While renowned for their duty cycles, they are rarely used in campers. |
| |
| ==== Carbon foam AGM === |
| |
| Firefly makes the Oasis (AGM) battery with carbon foam. Claimed benefits are: |
| * increased current acceptance |
| * Absorption stage required only 1x/month or so rather than every day or so. Since Absorption stage is long-duration, this can cut down charging time considerably. |
===== chain store batteries ===== | ===== chain store batteries ===== |
{{ https://i5.walmartimages.com/asr/523d2f9f-6552-48c6-928c-9eebf09ab0e9_1.3ffce13c71014acbc0a6c469b62333dc.jpeg?150}}"Deep cycle" / marine batteries found at Walmart and similar chains are not actually deep cycle batteries. Real 12v deep cycle batteries like the [[https://www.ebay.com/sch/items/?_nkw=trojan+T-1275&_sacat=&_ex_kw=&_mPrRngCbx=1&_udlo=&_udhi=&_sop=12&_fpos=&_fspt=1&_sadis=&LH_CAds=&rmvSB=true|Trojan T-1275]] are large, expensive, and very rarely seen in campers.((http://www.cheaprvliving.com/forums/Thread-Everstart-vs-Everstart-Maxx-batteries-at-Wal-Mart?pid=167108#pid167108)) | {{ https://i5.walmartimages.com/asr/523d2f9f-6552-48c6-928c-9eebf09ab0e9_1.3ffce13c71014acbc0a6c469b62333dc.jpeg?150}}"Deep cycle" / marine batteries found at Walmart and similar chains are not actually deep cycle batteries. Real 12v deep cycle batteries like the [[https://www.ebay.com/sch/items/?_nkw=trojan+T-1275&_sacat=&_ex_kw=&_mPrRngCbx=1&_udlo=&_udhi=&_sop=12&_fpos=&_fspt=1&_sadis=&LH_CAds=&rmvSB=true|Trojan T-1275]] are large, expensive, and very rarely seen in campers.((http://www.cheaprvliving.com/forums/Thread-Everstart-vs-Everstart-Maxx-batteries-at-Wal-Mart?pid=167108#pid167108)) |
| |
===== lithium chemistries ===== | ===== lithium chemistries ===== |
| |
| ==== LiFePO4 ==== |
| |
| |
In theory **LifePO4 lithium batteries** should be near perfect for boondocking. | In theory **LifePO4 lithium batteries** should be near perfect for boondocking. |
* CF [[http://www.cruisersforum.com/forums/f14/lifepo4-house-bank-using-smarthousepower-bms-40389.html|LiFePO4 house batteries]] | * CF [[http://www.cruisersforum.com/forums/f14/lifepo4-house-bank-using-smarthousepower-bms-40389.html|LiFePO4 house batteries]] |
| |
Other lithium chemistries like **"Li-ion" and "Li-po"** are rarely used. They are prone to thermal runaway (fire) and 3S packs do not line up well with 12v use. They are fully charged at 12.6v and and 80% discharged at ~11.2v.((3.73v per cell, https://www.rcgroups.com/forums/showthread.php?2953565-Lipo-Voltage-After-80-Discharge)) These lower voltages may trigger low voltage disconnect on devices that expect lead-acid range voltages. | ==== Non-LiFePO4 lithium-ion ==== |
| |
| Non-LiFeP04 Li-ion [called "li-ion" hereafter] are usually built in [[electrical:12v:parallel_serial|3S configuration]] and so run lower voltages than LFP or lead. Usable cell voltage is 4.2v - 3v, yielding bank voltage of **12.6v - 9v**.((https://batteryuniversity.com/learn/article/confusion_with_voltages)) This lower voltage may trip [[electrical:12v:lvd|Low Voltage Disconnect]] on [[electrical:inverter|inverters]] or [[food:refrigeration|refrigerators]]. |
| |
| |
| There are hobbyists who build 4S packs and undercharge the cells to only 3.7v. This gives an operating range of 14.8v - 12v, a much better fit for nominal 12v systems. The downside is this configuration only uses 58% of the cells' capacity and will require more cells to achieve the same amount of Ah. |
| |
| **7S builds** make a decent **24v bank**. They are 29.4v fully charged and 21v discharged, compared to lead acid's 29.6v max voltage and 24.2v 50% DoD cutoff. Discharging 7s li-ion to 24v((3.42v/cell) could help avoid LVD, making 35% of the cells' capacity unusable. |
| 24v banks in general could preclude [[electrical:12v:alternator|alternator charging]], however. |
| |
| |
| |
| **Pro:** |
| * About half the cost of LFP for the same Ah capacity |
| * widely available |
| |
| |
| **Con:** |
| * overcharging or physical damage can cause a runaway condition (ie fire) |
| * voltage mismatch - FIXME |
| |
7S banks make a decent 24v bank. They are 29.4v fully charged and 80% discharged at 26.11v, compared to lead acid's 29.6v max voltage and 24.2v 50% DoD cutoff. This could preclude alternator charging, however. | |
| |