Electrical Engineering Stack Exchange
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Questions tagged [lifepo4]

All related to lithium iron phosphate (or LFP) batteries

The LiFePO4 battery is a rechargeable, lithium-ion based chemestry based battery. This batteries share some of the advantages/disadvantages of other lithium based batteries. Although they have a particularly popular use nowadays for electric vehicles, because of the growing energy demand for user's devices, they became very popular, because of some of some of it's advantages, like the reduced effects of the temperature on discharge rate and number of lifecycles.

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Using LiFePO4 battery as car battery

I've had an idea of using LiFePO4 battery as replacement for car battery, since 4 of those in series make nominal 12.8V which is very close to standard 12V voltage. And depending on the cell we can parallel some to get required starting current.…
ozzo
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Does TI's LiFePO4 CV-free fast charge method reduce cell lifetime?

TI claim that you can charge LiFePO4 cells by CC (constant current) charging as usual but to a higher than usual voltage (eg 3.7V rather than the usual 3.6V for LiFePO4) and then step transition to a lower float voltage with NO intermediate CV mode.…
Russell McMahon
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What are the problems with LiFePo4 float charging? How should I charge them?

I can't find any reliable info on float charging LiFePo4 cells. It's quite clear that it's not possible to float charge Li-ion and Lipo cells, but LiFePo4 looks like quite different technology. I'm interested in building a simple charger using a…
Glubin
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LiFePo4 current limiter with supercapacitor in parallel

I am making a LiFePo4/supercapacitor-hybrid. Spike current draw can reach 300A for a few seconds. The LiFePo4 batteries I am using is rated for 100A max discharge rate. In order to make sure the supercapacitors do the heavy lifting, I need to limit…
skogs
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Solar powered single cell LiFePo4 charger circuit

As a follow-up to this question I've come up with this schematic for a solar powered battery charger: Subcircuits, from left to right: Solar cell (just a voltage source), 12V, 10W. Buck regulator with current limit set to about 300 mA, output…
Christoph
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LiFePo4 vs LiPo

I'm planning on building an Ebike and I am not quite sure what type of battery I should get. What are the bigger differences between the two? I have Googled, but I don't understand the answers. I don't care about weight and size, just efficiency,…
Arbitur
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How to fast charge a Lifepo4?

Disclaimer: I hope that I have not carelessly overlooked a previous post that answers this question; but I definitely have tried, and still find myself a little lost. Situation: I have 15 A123 ANR26650M1A batteries connected in series. They have a…
Alex Sky
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Solar powered charger circuit for a single LiFe cell

I'm looking for a solar powered charger circuit for a single LiFePo cell. The load is a low power MCU with some sensors attached, and when sufficient solar power is available, it should be used to charge the battery and supply the circuit. I had a…
Christoph
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18650 LiFePO4 Cell UVP/OVP Under/Over Voltage Protection

The vast majority of existing ancillary protection IC's available (such as Seiko) are not compatible with LiFePO4 chemistry due to the lower operating voltage. And the few vendors selling iron-phosphates often have a datasheet which is unclear about…
rdtsc
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LifePO4 battery to replace lead-acid

I want to replace my cargo van's lead-acid battery with a LifePO4 battery. Never used any li-ion type battery for high amp burst. The current lead-acid is NAPA The Legend Premium Battery BCI No. 75 690 A Wet, which is 850 Cranking Amp and 690 Cold…
SuperTimmyH
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Boost converter voltage drop when charging battery

I made a 4s battery pack made of 18650 LiFePO4 cells that I'm planning to use for a mobile computing hobby project. My plan for charging it is to use a salvaged power supply from a computer along with a boost converter on the 12 V rail to push the…
J T
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LiFePo4 cell risk of explosion during cool down

A 3 Ah LFP cell is charged to 100% at 25°C temperature. What happenes if I cool down the charged cell to -20 °C temperature? At -20 °C the cell can store only 2 Ah. Does it mean, the cell is overcharged by 1 Ah, equivalent to 30 %? Is there a risk…
Hans Kroeger
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What is the maximum static voltage of LiFePo4 batteries?

I've been working with a pack of batteries from a DIY electric vehicle. The batteries in the pack are LiFePo4 chemistry and were chosen for safety (greater resistance to thermal run-away), flat discharge curve (3.2-3.3v for 70% or so of the charge)…
Lunchbox
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How to drain LiFePO4 battery?

I am using a tracer battery BP2603(12V,3.5A) to turn on my camera. The camera needs 12V and it consumes max 3A. Maximum voltage the camera can accept is 13.5V. But I've found that when the battery is fully charged it has a voltage of approx 13.7v…
Dhinesh
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Load Sharing/Isolation Circuit with ADP5063

I'm designing the battery power/charging circuit for the Reform DIY laptop which uses a (big) LiFePo4 cell. For the charger IC I've now settled on ADP5063 as it seems simple and can charge with 1.5A current (more would be even better, but hey...).…
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