LiFePO4 vs LiPo vs Lead Acid for LoRa Deployments

LiFePO4 vs LiPo vs Lead Acid for LoRa Deployments

Choosing the right battery chemistry for a LoRa mesh node is one of the most consequential hardware decisions you will make. The chemistry determines cycle life, safe operating temperature, charging behaviour, physical size, and total cost of ownership. This page provides a deep technical comparison of the three chemistries most commonly encountered in field deployments: Lithium Iron Phosphate (LiFePO4), Lithium Polymer (LiPo), and valve-regulated lead acid (VRLA/AGM).

Chemistry Overview

Property	LiFePO4	LiPo (LiCoO₂/NMC)	Lead Acid (AGM/VRLA)
Nominal cell voltage	3.2 V	3.7 V	2.0 V per cell (12 V = 6 cells)
Fully charged voltage	3.65 V	4.2 V	12.7–12.8 V (12 V battery)
Fully discharged cutoff	2.5 V (3.0 V recommended)	3.0 V (3.2 V recommended)	10.5 V (50% DoD recommended)
Usable energy density (Wh/kg)	90–120 Wh/kg	150–200 Wh/kg	30–40 Wh/kg
Cycle life (to 80% capacity)	2,000–4,000 cycles	300–500 cycles	200–500 cycles (50% DoD)
Self-discharge per month	1–3%	2–5%	3–5%
Thermal runaway risk	Very low — does not propagate	High — flammable electrolyte	Low — explosive H₂ gas if overcharged
Operating temperature (discharge)	−20 °C to +60 °C	−10 °C to +45 °C	−15 °C to +50 °C (capacity drops >30% at 0 °C)
Charging temperature minimum	0 °C (lithium plating below)	0 °C	−20 °C (reduced rate)
Typical cost (USD, 2024)	$0.25–$0.50 / Wh (cells); $0.60–$1.20 / Wh (pack)	$0.15–$0.30 / Wh (pouch)	$0.10–$0.20 / Wh
Cost per cycle (at rated life)	$0.0002–$0.0006 / Wh / cycle	$0.0006–$0.0010 / Wh / cycle	$0.0004–$0.0010 / Wh / cycle

Cycle Life in Depth

LiFePO4 is the standout performer for longevity. A quality cell from EVE, CALB, or Headway will reliably deliver 2,000 cycles at 100% depth of discharge (DoD) and can exceed 4,000 cycles at 80% DoD. At a 1-cycle-per-day charge rate typical of solar nodes, this translates to 5–11 years of service life.

LiPo cells (using LiCoO₂ or NMC cathodes as found in hobby packs and phone batteries) are rated for 300–500 full cycles. With daily cycling on a solar node, these cells will reach end-of-life in under 18 months. The LP503562 3.7 V 1100 mAh pouch cell common in hobbyist builds, for example, is typically rated 300 cycles by the manufacturer. Permanent deployments in LiPo are therefore not economical.

Lead acid (AGM) ratings of 200–500 cycles assume 50% DoD. Going to 80% DoD halves the cycle count. Because solar systems routinely deep-discharge during extended cloudy periods, real-world lead acid life in solar applications is often only 2–3 years.

Temperature Performance

This is where LiFePO4 dominates cold climates. At −20 °C, LiFePO4 retains approximately 70–80% of rated capacity on discharge — usable, though not ideal. LiPo cells at −10 °C typically retain only 50–60% of rated capacity and internal resistance rises sharply, causing voltage sag under load. At −20 °C many LiPo cells effectively stop functioning. Lead acid loses approximately 30–40% of rated capacity at 0 °C, and at −20 °C a fully charged lead acid battery delivers only 40–50% of its 25 °C rating.

Critical charging constraint: Both LiFePO4 and LiPo must not be charged below 0 °C. Charging lithium cells in freezing temperatures causes metallic lithium plating on the anode, permanently reducing capacity and creating an internal short-circuit hazard. Solar systems in freezing climates must incorporate a low-temperature charge cutoff. Many commercial LiFePO4 BMS modules include this feature.

Safety

LiFePO4 uses an olivine phosphate cathode that is inherently stable. Even in nail-penetration and overcharge abuse tests, LiFePO4 cells typically vent mildly without fire or explosion. This makes them suitable for enclosed enclosures and attic/wall installations.

LiPo cells with NMC or LiCoO₂ cathodes store significantly more energy per unit mass and release it rapidly in fault conditions. Thermal runaway in a LiPo pack can reach temperatures exceeding 600 °C and produces toxic HF gas. Never install LiPo packs in sealed enclosures without adequate ventilation or thermal fusing. For unattended LoRa repeater deployments in public locations, LiPo represents a meaningful liability.

Lead acid produces hydrogen gas during overcharge. In sealed VRLA/AGM formats the recombination rate is high, but a faulty charge controller can still cause pressure build-up and case rupture. AGM batteries should not be enclosed in airtight boxes.

Voltage Curves and State-of-Charge Estimation

LiFePO4 has an extremely flat discharge curve — the cell voltage sits near 3.2–3.3 V for the majority of its capacity range, dropping steeply only in the last 10–15% of charge. This makes voltage-based SoC estimation imprecise in the mid-range, but the flat curve is beneficial because the node's voltage regulator sees a near-constant input for most of the discharge cycle.

SoC (%)	LiFePO4 OCV (V/cell)	LiPo OCV (V/cell)	12 V Lead Acid OCV (V)
100	3.60–3.65	4.18–4.20	12.70–12.80
90	3.35–3.38	4.07–4.10	12.50–12.60
80	3.32–3.34	3.98–4.02	12.40–12.50
70	3.30–3.33	3.88–3.92	12.30–12.40
50	3.27–3.30	3.73–3.77	12.10–12.20
30	3.22–3.25	3.60–3.65	11.90–12.00
20	3.18–3.22	3.55–3.60	11.75–11.90
10	3.10–3.18	3.45–3.55	11.50–11.75
0 (cutoff)	2.5–3.0	3.0–3.2	10.5–11.2

All OCV values are resting voltage with no load applied for at least 30 minutes. Under load, voltages will be lower due to internal resistance. For LiFePO4, Meshtastic firmware reports battery percentage based on voltage thresholds; refer to the telemetry page in this book for specific ADC configuration.

Specific Product Recommendations

LiFePO4 — Recommended Products

• EVE LF50K (50 Ah, 3.2 V prismatic): Grade A cells widely used in DIY packs. ~$15–20 USD per cell from Chinese suppliers. Rated 3,000 cycles at 1C. Excellent for 12 V 4S packs powering Pi gateways.
• Headway 38120S (10 Ah, 3.2 V cylindrical): Threadable terminals, very robust, 2,000+ cycle rating. Good for vibration-prone installations.
• Bioenno Power BLF-1206A (6 Ah, 12.8 V): Complete sealed pack with integrated BMS, ~$60–70. Designed for portable amateur radio use. Plug-and-play for most repeater boxes.
• Dakota Lithium 12V 7Ah: ~$55, includes BMS, designed for marine environments, IP65-rated case. Excellent for outdoor enclosures.

LiPo — Acceptable for Short-Deployment or Prototype Use

• EEMB LP805060 (3.7 V, 3000 mAh): Popular single-cell pouch for T-Beam style boards, includes built-in PCM protection board.
• Adafruit 328 (3.7 V, 2000 mAh): JST PH 2.0mm connector, compatible with most Adafruit LoRa boards out of the box.
• Tenergy LP 103450 (3.7 V, 1800 mAh): Flat pouch, low profile for tight enclosures.

Lead Acid — Only Where Weight/Cost Dominates

• Mighty Max ML7-12 (12 V, 7 Ah AGM): ~$20, widely available. Suitable for short-duration backup where replacement is routine.
• Universal Power Group UB1270 (12 V, 7 Ah): UL-listed, common in security system applications, drop-in for 12 V enclosures.

Summary Recommendation

For any unattended LoRa repeater or mesh node intended for permanent or semi-permanent deployment, LiFePO4 is the correct choice. The superior cycle life, wide temperature tolerance, and thermal safety profile outweigh its higher per-Wh cost compared to LiPo. Lead acid remains viable only when cost is the dominant constraint and the installation allows for routine (annual) battery replacement. LiPo is acceptable for short-term field deployments, handheld nodes, and prototyping, but should not be used in sealed enclosures or unattended permanent installations.