The cheaper battery usually isn't
Lead-acid gives you half of what the label says.
Lead-acid gives you half of what the label says.
That's the whole comparison in one line. To match a lithium bank you need roughly twice the lead-acid capacity — so the cheaper option just doubled.
Cycle life. Quality lead-acid gives a few hundred to maybe a thousand cycles. LiFePO₄ commonly delivers 3,000–5,000+. Cycling daily, that's replacing your bank every few years versus approximately never.
Weight. Roughly half, for the same usable capacity. In a rig, weight is payload.
Charging behavior. Lead-acid slows dramatically as it fills — the last 20% takes hours, which means you lose your best solar window to a battery that won't accept it. Lithium takes high current nearly to full.
Where lead-acid still wins: genuinely cold environments where you can't charge lithium below freezing, very tight budgets where the upfront number is the only number, and starter batteries — a different job entirely.
The Power Sizer turns your real appliance loads into a full spec — battery bank, solar array, controller, inverter and roof space — then matches it to gear that actually fits the number.
Open the Power SizerFree · no ads · no signup