5ah vs 9ah 20v Battery: Which One Should You Buy?

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Below: what the amp-hour rating means, how the 4 packs in this guide compare, and how to match a pack to the job and the charger already on the bench.

5ah vs 9ah 20v battery: what the amp-hour rating means

The amp-hour figure is the pack’s charge capacity. A pack rated at 5Ah stores a stated charge; a pack rated at 9Ah stores a larger stated charge. Voltage is a separate rating: every pack in this guide is listed at 20 volts, and the DEWALT listings describe compatibility with 20V MAX* tools and chargers. Capacity is the charge the pack stores, and runtime also depends on the tool drawing that charge, so a larger charge does not by itself fix a runtime figure. Voltage must match the tool’s system, but voltage alone does not decide fit: the pack must also match the platform and the battery interface. A larger charge can suit long stretches of cutting, drilling or driving, while a smaller charge suits work that does not need the extra charge.

Charging is a separate question from capacity. The LiBatter charger listing states support for 100-240V at 2.0A and a 90 mins charge for DeWalt 12V-20V max lithium-ion batteries. The Bslite set includes a charger, and its battery lists replacement compatibility with DCB200, DCB201, DCB203, DCB204, DCB206 and DCB207 batteries. Note a mismatch in that listing: the title names a DCB112 charger station, while the bullets name a DCB102 charger replacement. Match the charger to the pack platform before buying, and follow the charger manual.

The 4 packs in this guide, ranked

The packs below are ranked from the highest scoring listing to the lowest, on warranty term, charger inclusion and stated protections. Capacity does not separate them, since every pack here is rated at 5Ah or 5000mAh. Every pack here is rated at 5Ah or 5000mAh; no 9Ah pack appears in the listings for this guide, so the 9Ah side of the comparison is covered by the capacity explanation above and the buying guidance below.

DEWALT 20V MAX 5 Ah Lithium Ion Battery 2-Pack (DCB205-2). The listing states a 5Ah capacity, an LED indicator with 3 LED fuel gauges, and a 3 year limited warranty, and it includes 2 DCB205 batteries for the 20V MAX* system. It ranks first because it pairs the longest warranty term in this guide with a spare pack, so a drained pack can be swapped for the spare, provided a charger is on hand, since this listing includes no charger. Note a contradiction in the listing: the bullets describe the battery at 1.4 lbs, while the spec table lists 2.8 pounds.

DEWALT 20V MAX Battery, Lithium Ion, 5.0Ah (DCB205). The single-pack version of the same battery, with the same 5Ah capacity, LED indicator and 3 Year Limited Warranty, and the same 20V MAX* compatibility. It ranks second only because it includes 1 battery instead of 2. The spec table lists its item weight at 1.5 pounds.

Bslite 20v Max Battery Replacement for Dewalt Battery 5.0Ah with DCB112 Battery Charger Station. A replacement pack rated at 5000mAh with a charger station, an LED indicator, and built-in BMS protection against overcharging, over discharge, over current and short circuiting. The listing states ABS+PC material and 12 months of free replacement, and it lists compatibility with DCB200, DCB201, DCB203, DCB204, DCB206 and DCB207. It ranks third: the charger and the stated protections add value, but the replacement term is briefer than the DEWALT warranty term. Note a contradiction in this listing: the bullets describe a lithium-ion replacement with no memory effect, while the spec table lists the cell type as NiMH. Trust the title and bullets over the spec table here, and confirm the cell type on the listing before buying.

LiBatter 2Packs 5.0Ah Battery Replacement for Dewalt 20v Battery with DCB102 Battery Charger Station (Yellow). A set of 2 packs rated at 5.0Ah with a DCB102 charger station in Yellow. The charger listing states 100-240V input at 2.0A, a 90 mins charge for DeWalt 12V-20V max lithium-ion batteries, LED diagnostics, and safeguards against overcharging, overloading, overheating and short circuiting. The listing states a 1 year warranty and 30 days free return and replacement. It ranks fourth: the charger and the 2-pack format are useful, but the 1 year warranty term trails the 3 year term on the DEWALT packs.

How to choose between a 5Ah pack and a 9Ah pack

• Match the platform. The DEWALT listings describe 20V MAX* tools and chargers; the replacement packs list compatibility with Dewalt 20V tools and chargers and with the DCB200 series batteries. A pack that does not match the platform and the battery interface does not help, whatever its capacity.
• Weigh runtime against handling. A larger charge stores more energy, so on the same tool it can run longer between swaps. A smaller pack is the lighter-handling option only if its stated weight beats the larger pack’s stated weight, and the 5Ah packs in this guide list weights of 1.4 lbs and 1.5 pounds. No 9Ah pack weight is stated in the listings in this guide.
• Check the charger. The LiBatter charger listing states 100-240V, 2.0A and a 90 mins charge for DeWalt 12V-20V max lithium-ion batteries, while the Bslite listing states no charger voltage, current or charge time. Confirm the charger fits the pack before buying.
• Compare warranty terms. The terms in this guide are a 3 year limited warranty on the DEWALT packs, 12 months of free replacement on the Bslite pack, and a 1 year warranty on the LiBatter set. A free replacement term is not the same kind of term as a limited warranty, so read the term on the listing, not just the headline claim.
• Consider a spare. The 2-pack sets in this guide let a drained pack be swapped for a charged pack, which keeps a long job moving while the drained pack charges, provided a charger is on hand and the spare is charged.

FAQ: garage tools

Can a 9Ah battery run a tool made for a 5Ah battery?

Voltage and platform both have to match: the pack must fit the tool’s battery interface and its 20V MAX* system, not merely share a 20V label. The packs in this guide are described as compatible with 20V MAX* tools and chargers, and a 9Ah pack on the same platform keeps the same 20V rating while adding charge capacity. Check the tool manual and the listing compatibility list before buying.

Does a 9Ah pack need a different charger?

Not necessarily a different kind of charger, but the charger has to fit the platform, and charge time depends on the charger and the pack. The charger listings in this guide state support for DeWalt 12V-20V max lithium-ion batteries and for the DCB200 series, and the DEWALT packs work with 20V MAX* chargers per their listings. Follow the charger manual for the pack in hand.

Why does a 5Ah pack feel lighter in hand?

It may not: weight depends on the cells and housing, not on the amp-hour figure alone, so a smaller charge capacity does not by itself mean a lighter pack. The 5Ah packs in this guide list weights of 1.4 lbs and 1.5 pounds. No 9Ah pack weight is stated in the listings in this guide, so compare the stated weight on the listing for the pack being considered.

What does the LED indicator do?

The listings describe the LED indicator as a state-of-charge display that shows the remaining charge at a glance, so a swap can be planned before the pack quits. The DEWALT 2-pack listing states 3 LED fuel gauges for that reading.

Which warranty terms do these packs carry?

The DEWALT packs carry a 3 year limited warranty. The Bslite pack lists 12 months of free replacement. The LiBatter set lists a 1 year warranty and 30 days free return and replacement. The term on the listing is the term that counts.

Related: 4Ah vs 9Ah 20V battery, our battery charger maintainer picks, the battery platform for mechanics guide, and the cordless tools hub.