Upgrading from AGM or lead-acid to LiFePO4? Enter your current setup and see the weight savings, usable capacity gain, charger changes, cable notes, and everything else you need to know.
System Voltage
Current Lead-Acid Battery
Battery type
Planned LiFePO4 Battery
Battery size
-80kg
weight change
104kg → 24kg
-120Wh
usable capacity
2400Wh → 2280Wh
6x
longer cycle life
500 → 3000 cycles
| Metric | AGM | LiFePO4 |
|---|---|---|
| Total capacity | 400Ah | 200Ah |
| Usable capacity | 200Ah (50%) | 190Ah (95%) |
| Usable energy | 2400Wh | 2280Wh |
| Weight | 104kg | 24kg |
| Cycle life | ~500 cycles | ~3000 cycles |
| Charge efficiency | 85% | 99% |
| Self-discharge | 3%/month | 0.5%/month |
| Maintenance | None | None |
| Charge voltage | 14.4V absorption | 14.2–14.6V absorption |
Key benefits of LiFePO4
Flat discharge curve — voltage stays stable until nearly empty, unlike lead-acid which sags under load
Can be discharged to 95% without damage — lead-acid should only go to 50% to preserve cycle life
Charges 3–5x faster — accepts high charge current without damage
No memory effect — can be partially charged and discharged freely
Safe chemistry — LiFePO4 is the most thermally stable lithium chemistry, no thermal runaway risk
Works in any orientation — no acid spill risk
Lithium Upgrade Checklist
Remove old AGM batteries
Install 200Ah LiFePO4 battery (2 × 100Ah)
Install Class T fuse within 300mm of positive terminal
Install battery isolator switch rated for new current
Update MPPT charger to LiFePO4 charge profile
Replace VSR with DC-DC charger (if applicable)
Update inverter-charger to LiFePO4 charge profile
Update DC-DC charger to LiFePO4 profile (or replace)
Install battery monitor / shunt (if battery has no Bluetooth)
Verify all cable sizes are adequate for current draw
Check lug sizes match new battery terminal size
Label all cables with polarity and voltage
Test system at no-load before connecting appliances
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