Where This Guide Comes From
This guide is built on GreatScott!'s battery type comparison video, which has just under 700,000 views. What makes the test useful is the method: every battery was bought online like a normal customer would, then measured for weight, volume and delivered energy. No datasheet averages, no lab-only cells — just four common chemistries that anyone can order today. We walk through the same numbers here and add the practical notes that matter when you are sizing a real project.
Why Chemistry Still Decides Your Project
Every portable electronics project starts with the same four candidates: sealed lead acid, nickel-metal hydride (NiMH), lithium-ion (Li-Ion) and lithium polymer (LiPo). The chemistry you pick sets the weight you carry, the box you design, the charger you buy and the safety margin you need to respect. The video tests one representative of each: a 12V 4.5Ah lead-acid block, a single 1.2V NiMH cell, an 18650 Li-Ion cell and a LiPo pack. It is a small sample, but the results line up with what we see in our own packs — and they explain why the battery market settled the way it did.
Energy Density: Weight and Volume Compared
Energy density is the first thing buyers notice. The lead-acid unit delivers 54Wh at 1,652g and roughly 0.59 litres — about 33Wh per kilogram. That is the reference point everything else is compared against. The NiMH cell, at 30g and a fraction of the volume, reaches three to four times the gravimetric and volumetric energy density of lead acid. The 18650 Li-Ion cell beats them both easily: 9Wh in 33g and only 0.017 litres. LiPo sits between NiMH and Li-Ion for weight-based density, and its volumetric density actually comes out below NiMH in this test — surprising to many people, and worth remembering before you assume a pouch cell is the most compact option.
Price: Energy per Dollar
The catch with lithium is cost. In this comparison Li-Ion is the most expensive way to store a watt-hour, and the LiPo cells land in second place at roughly $0.89 to $1.30 per watt-hour depending on the pack. NiMH works out to about 0.69Wh per dollar at the tested price of around $4.24 per cell. Lead acid, as everyone expects, is the cheapest storage of the four. If a project is budget-driven and weight is not critical, the lead-acid price advantage is hard to argue with; if you need the energy density, you pay for it.
Price per watt-hour also changes with pack size, which is where a single-cell comparison can mislead. Buy one 18650 and you pay retail per cell; buy a thousand and the same cell drops dramatically in cost. That is why a cheap-looking lead-acid setup stays competitive at small scale, while large builds — solar banks, golf carts, whole-home backup — flip decisively to lithium on price per cycle. If you are comparing a replacement battery for a real machine rather than a hobby project, work out the cost over the expected lifetime, not the sticker price.
Cycle Life, Self-Discharge and Charge Efficiency
The video focuses on energy density and price, but viewers asked about the rest of the picture — and the chemistry differences are real. Lead acid tolerates being left at partial charge, but its cycle life is counted in hundreds rather than thousands, and it self-discharges faster than lithium. NiMH has a moderate cycle life and a well-known self-discharge problem, though modern low-self-discharge cells have improved that a lot. Li-Ion and LiPo offer the longest cycle life in normal use, low self-discharge and the best round-trip efficiency, which is exactly why they dominate anything that gets charged daily.
Round-trip efficiency is the number people skip, and it adds up. Lithium returns well over 90% of the energy you put in, lead acid noticeably less, and the difference shows up in anything solar or off-grid where every charge cycle is a small financial event. Add self-discharge on top and a lithium pack that sits for a month loses a fraction of what lead acid loses. For equipment that is used rarely — emergency lights, backup controllers, seasonal gear — that quiet advantage can be bigger than the headline energy-density numbers.
Discharge Performance and Internal Resistance
High-drain projects separate the chemistries even faster than capacity does. LiPo wins on sustained high discharge because its internal resistance is low, so voltage holds up under load. Li-Ion is close behind, especially with cells chosen for discharge rating rather than capacity. NiMH can push reasonable current but sags under heavy loads, and lead acid sags the most — a 12V block can sit well below its nominal voltage when a big load is connected. If your device pulls several amps, the lithium chemistries are not a luxury, they are the difference between usable voltage and brownout.
Internal resistance also explains why a battery can read full voltage when idle and still fail instantly under load. The video’s measurement approach — real current draw, real voltage sag — is the right way to compare, and it is the same reason we test complete packs rather than trusting cell datasheets alone. When you choose a battery for a motor, an inverter or anything with inrush current, ask for the continuous discharge rating and the voltage curve under load, not just the capacity sticker.
Cold Weather Behaviour
Temperature matters on both ends of the scale. Lead acid keeps working in deep cold better than most people expect, which is why it still appears in winter-storage and automotive applications. NiMH performs poorly in the cold and loses capacity noticeably. Li-Ion and LiPo are the most temperature-sensitive of the group: charging below freezing is genuinely dangerous and can damage cells, and even discharging in the cold drops available capacity. The video’s commenters raised both cold performance and operating temperature, and they are right — chemistry choice is also a climate decision.
Safety and Charging Requirements
This is where the comparison turns serious. Li-Ion and LiPo need a precise constant-current / constant-voltage charging profile; a small overcharge, over-discharge or short circuit can destroy the cell and things around it. Multi-cell LiPo packs additionally need a balance charger that watches each cell so none gets overcharged. NiMH also needs a controlled constant-current charger, but it is far less likely to cause harm when something goes wrong, which makes it the beginner-friendly portable option. Lead acid endures the most abuse of the four — overcharge, over-discharge and rough handling — with the least risk to people nearby, which keeps it in the "safest chemistry" spot.
Head-to-Head Spec Table
| Spec | Lead Acid | NiMH | Li-Ion (18650) | LiPo (3S) |
|---|---|---|---|---|
| Nominal voltage | 12V | 1.2V | 3.6V | 11.1V |
| Capacity (tested) | 4.5Ah | 2.45Ah | 2.5Ah | 4Ah |
| Energy (tested) | 54Wh | 2.94Wh | 9Wh | 44.4Wh |
| Weight (tested) | 1,652g | 30g | 33g | pack-dependent |
| Weight energy density | ~33Wh/kg (baseline) | 3–4× lead acid | Highest of the four | Between NiMH and Li-Ion |
| Relative cost | Cheapest | ~0.69Wh/$ | Most expensive | $0.89–1.30/Wh |
| High-drain discharge | Sags under load | Moderate | Very good | Best of the four |
| Cold tolerance | Good | Poor | No charging below 0°C | Same as Li-Ion |
| Charging | Simple, tolerant | Controlled CC needed | Strict CC-CV | CC-CV + balancing |
| Safety under abuse | Most forgiving | Beginner-friendly | Needs protection | Needs protection + balance |
The table condenses what the video measured. Keep in mind that "tested" numbers are single samples — real cells from different batches vary a little — but the relationships between the four chemistries are stable and match datasheets across brands.
Which Battery Should You Pick?
The video’s conclusion holds up in practice. Lead acid is big and heavy but cheap and genuinely safe to work with — perfect for low-budget, stationary projects where portability does not matter. NiMH does not offer the best energy density for its size, but it is relatively easy to charge and forgiving, so it is the right portable chemistry for beginners. Li-Ion and LiPo give you the best energy density, at the price of higher cost and stricter handling: they need proper chargers and protection circuits. If your project is portable and you are comfortable with battery protection basics, lithium is the honest recommendation.
When the project grows past a single cell or pack — a power station, a golf cart, a home backup bank — the chemistry question stops being about one cell and becomes about the whole battery system. That is where a manufacturer’s engineering matters more than the chemistry datasheet, and where buying a built pack beats assembling loose cells for most people.
And if you’re not hunting for a consumer brand but need the battery itself — a custom LiFePO4 pack at a specific voltage and capacity, an OEM or ODM project, or wholesale supply for your own power station line — that’s what we do. Dajiu Energy is a Chinese manufacturer building LiFePO4 batteries for RVs, homes, golf carts and portable applications since 2017. Our product range covers LiFePO4 drop-in replacement batteries, EV and golf cart batteries, wall-mounted home storage, portable power stations and industrial stackable systems, with CE, UN38.3, MSDS and ISO9001 certified builds and OEM/ODM support. Browse the full product range or read more battery guides before you decide.
What Viewers Are Asking (Top Comments on the Video)
These are the most useful of the video's top comments, with our practical answers. The original creator did not reply to these threads, so the answers below are ours — written the way we'd answer a customer on the shop floor. Thanks-only comments were left out on purpose; these are the ones with actual information in them.
Source video: GreatScott! — "Battery Type Comparison || Lead Acid VS NiMH VS Li-Ion VS LiPo" (youtube.com/watch?v=LqgP16JQ24I). Comment excerpts are quoted verbatim from the video's top comments; the original creator did not reply to these threads, so all answers are Dajiu Energy's own. Build figures are transcribed from the video's measurements.