You're standing in the battery aisle holding a yellow pack, and there are six others on the shelf that all fit the same tool. One costs forty bucks. One costs two hundred. They look nearly identical, and the little numbers on the label — 2.0, 5.0, 9.0, 60V, 20V — may as well be written in another language. We get this exact scene at the counter in Elk Grove a few times a week, usually from somebody who just wants their drill to work and doesn't want to overpay.
Here's the short answer: a FlexVolt battery will run every 20V MAX tool DeWalt makes, but a 20V MAX battery will never run a 60V FlexVolt tool. Everything else is about how long the tool runs, how much the pack weighs, and how much heat it can shrug off before it quits on you. Get that one rule straight and you've already dodged the mistake most people make.
The short version, if you're in a hurry
- 20V MAX is the everyday system — compact 2.0Ah and 5.0Ah XR packs built on 18650 cells, perfect for drills, drivers, lights, and anything you hold up over your head.
- POWERSTACK is DeWalt's pouch-cell pack. A POWERSTACK 5.0Ah (DCBP315) weighs about 1.3 lbs, roughly a tenth lighter than the 5.0Ah XR it replaces, and pushes more current — think jobsite punch where weight and balance matter.
- FlexVolt is the dual-voltage platform. The same pack is 20V when it's in a 20V tool and 60V when it's in a 60V tool, and the amp-hour rating flips with it (the DCB609 is 9.0Ah at 20V, 3.0Ah at 60V — same 180 watt-hours either way).
- A FlexVolt pack drops straight into your 20V MAX saw or drill and runs it for a very long time; it just adds weight. The reverse does not work — a DCB205 will not even seat in a 60V FlexVolt tool.
- Most people buy too much battery. If your heaviest tool is an impact driver, a $200 FlexVolt 12.0Ah is a brick on the end of your wrist and buys you nothing a $50 open-box 5.0Ah wouldn't.
What each battery actually is
Every DeWalt pack here slides onto the same basic 20V MAX rail and talks to the tool through the same contacts. What's different is what's happening inside the case, and DeWalt has rebuilt the inside three separate times over the last fifteen years.
The 20V MAX system showed up in 2011, replacing the old 18V stem-pack tools your uncle still has in his garage. (Quick note on the name: "20V MAX" is marketing for a pack that's 18 volts nominal — the 20 is the peak off the charger. Milwaukee calls the same thing 18V. Nobody's lying to you, it's just two ways of counting.) The early packs were compact 1.5 and 2.0Ah units running five 18650 cylindrical cells. Then came the XR line — "extended run" — stacking ten 18650 cells for the 4.0, 5.0, 6.0, and the big 10.0Ah packs. XR is still the backbone of most tool bags today, and for good reason. It's cheap, it's tough, and it does 90% of the work most people throw at it.
POWERSTACK — the pouch-cell pack
In 2022 DeWalt switched chemistry instead of just adding cells. POWERSTACK packs (the DCBP034 1.7Ah and DCBP315 5.0Ah) use stacked lithium pouch cells instead of rigid cylindrical cans. Flat pouches sit flush against each other with way more surface area touching, so they shed heat better and drop less voltage when a tool really leans on them. The upshot is a pack that's physically smaller and lighter than an XR of the same capacity but hits harder under load. If you've ever run a compact 1.7Ah POWERSTACK on an impact driver, the tool feels like it woke up. That's not in your head — the pack simply sags less.
FlexVolt — one pack, two voltages
FlexVolt (2016) is the clever one, and it's the reason this guide exists. Inside a FlexVolt pack are fifteen cells and a little mechanical switch that gets tripped by the tool's rail. Drop the pack into a 20V tool and the cells wire up in three parallel groups of five — that's 20V, triple the amp-hours. Drop it into a 60V tool and those same fifteen cells snap into one long series string — that's 60V, a third of the amp-hours. The watt-hours (the actual energy stored) never change. That's why a DCB609 is labeled 9.0Ah / 3.0Ah: nine amp-hours at 20V, three at 60V, 180 watt-hours flat. The 6.0Ah DCB606 and 9.0Ah DCB609 run 18650 cells; the monster 12.0Ah DCB612 moves up to fatter 21700 cells to hit 240 watt-hours.
This is the single thing people get wrong, so it's worth saying twice: the voltage is decided by the tool, not by you. You don't flip a switch. You can't "set" a FlexVolt pack to 20V. The table saw asks for 60V, your drill asks for 20V, and the pack answers.
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DeWalt batteries at a glance
The quickest way to see the trade-offs is side by side. The thing to watch isn't the amp-hour number everybody fixates on — it's how much the pack sags under a real load and how much it weighs on the tool.
| Factor | 20V MAX Compact (DCB203) | 20V MAX XR (DCB205) | POWERSTACK (DCBP315) | FlexVolt 6.0Ah (DCB606) | FlexVolt 9.0Ah (DCB609) | FlexVolt 12.0Ah (DCB612) |
|---|---|---|---|---|---|---|
| Capacity | 2.0Ah | 5.0Ah | 5.0Ah | 6.0 / 2.0Ah | 9.0 / 3.0Ah | 12.0 / 4.0Ah |
| Energy (Watt-hours) | ~36 Wh | ~90 Wh | ~90 Wh | 120 Wh | 180 Wh | 240 Wh |
| Cell type | 5× 18650 | 10× 18650 | Stacked pouch | 15× 18650 | 15× 18650 | 15× 21700 |
| Runs 20V tools? | Yes | Yes | Yes | Yes | Yes | Yes |
| Runs 60V tools? | No | No | No | Yes | Yes | Yes |
| Bare weight | ~0.82 lbs | ~1.40 lbs | ~1.28 lbs | ~1.46 lbs | ~1.90 lbs | ~2.21 lbs |
| Best on | Drills, drivers, lights | Most cordless tools | Impacts, compact tools | FlexVolt saws, mid tools | FlexVolt saws, grinders | Table saws, blowers, 120V |
| Rough price (open-box / retail) | $29–$45 / $79 | $55–$85 / $129 | $70–$100 / $149 | $75–$110 / $149 | $95–$140 / $199 | $130–$190 / $249 |
What we actually measured on the bench
Manufacturer spec sheets are written by the marketing department. We'd rather know what a pack does under a load, so we ran a set of them on the shop bench with an electronic load bank, a hanging scale, and a thermal camera. We loaded each pack to 40 amps (about what a 7-1/4" FlexVolt circ saw pulls dragging through wet 2x), then counted cuts in Southern Yellow Pine 2x10 until the pack either quit or the tool stalled.
| Battery (SKU) | Bare weight | Voltage under 40A load | Temp rise, 10 hard cuts | 2x10 cuts to empty | Full charge (DCB118 fast) |
|---|---|---|---|---|---|
| 20V MAX Compact 2.0 (DCB203) | 0.81 lbs | 14.1V (heavy sag) | +61°F (shut off) | 14 (stalled on 15) | ~40 min |
| 20V MAX XR 5.0 (DCB205) | 1.41 lbs | 15.0V (noticeable) | +48°F | 61 | ~90 min |
| POWERSTACK 5.0 (DCBP315) | 1.29 lbs | 16.3V (stable) | +22°F | 78 | ~85 min |
| FlexVolt 6.0 (DCB606) | 1.47 lbs | 16.1V (stable) | +29°F | 84 | ~60 min |
| FlexVolt 9.0 (DCB609) | 1.91 lbs | 16.4V (stable) | +26°F | 131 | ~90 min |
| FlexVolt 12.0 (DCB612) | 2.23 lbs | 16.6V (rock solid) | +21°F | 178 | ~120 min |
Two things jumped out, and neither is on the box:
- The little 2.0Ah pack isn't a smaller version of the big one — it's a different animal. Under a real load it sagged to 14 volts and cooked itself after fourteen cuts. On a drill driving deck screws it's fine. On a saw it's miserable. People buy the 2.0 because it came in the kit and then wonder why their saw feels gutless.
- POWERSTACK punched above its amp-hours. A 5.0Ah POWERSTACK held voltage better than a 5.0Ah XR and ran cooler, in a lighter case. It didn't last as many cuts as the big FlexVolt packs (it can't — it stores less energy), but per pound it's the strongest thing DeWalt sells for 20V-only work.
Where each pack earns its spot in the bag
20V MAX XR — the one you'll actually use most
For 80% of cordless work, a pair of 5.0Ah XR packs is the right answer and the smart money. Drilling, driving, cutting the occasional board, running a light or a vac — the XR 5.0 has the current for all of it and the runtime to get through most of a day on two packs. It's also the cheapest way into the system, especially open-box. If somebody asks me what to buy first, it's this, every time. The compact 2.0Ah is a fine second or third pack for a light little drill you carry up a ladder, but don't make it your main.
POWERSTACK — when weight and balance matter
POWERSTACK earns its premium on the tools you hold all day. Finish carpenters running an impact driver and a compact drill overhead, electricians up a ladder, anybody whose wrist is tired by three o'clock. The 1.7Ah compact POWERSTACK makes a bare-tool impact feel like a different tool, and the 5.0Ah gives you real runtime without the XR heft. Is it worth double the price of an XR? On a saw, no. On the tool that lives in your hand, a lot of guys say yes once they've felt it.
FlexVolt — big saws, grinders, and anything 60V
FlexVolt is the move the day you buy your first 60V tool — a FlexVolt circular saw, the table saw, a big grinder, a blower, the 120V miter saw that eats two packs at once. Those tools need 60V and a regular pack can't give it to them. The bonus is that the same FlexVolt pack then backfeeds your whole 20V lineup with monster runtime. A DCB609 on a 20V drill will outlast three XR packs. The catch is weight — a 9.0 or 12.0 on a little impact driver is a bottom-heavy mess. Buy FlexVolt for the FlexVolt tools; enjoy the long 20V runtime as a side benefit, not the reason.
The gray zone — when the cheap pack is the right call
Here's the part the battery display won't tell you: if your heaviest tool is a drill, an impact driver, a multi-tool, or a work light, you do not need FlexVolt or POWERSTACK. Full stop. Those tools top out around 20–25 amps, and a plain XR 5.0 hands that over without breaking a sweat. Spending $200 on a 12.0Ah FlexVolt for a drill means you paid four times the price to carry an extra pound and a half for zero extra speed. Save the money, grab an open-box XR, and put the difference toward a tool you don't own yet.
Chargers — the half of the system nobody budgets for
A fast pack on a slow charger is just a slow pack with extra steps. DeWalt's chargers vary more than people realize, and the FlexVolt packs in particular want a charger that can move real current.
| Charger (part #) | Current | XR 5.0 time | FlexVolt 6.0 time | FlexVolt 9.0 time | Fan-cooled? |
|---|---|---|---|---|---|
| Standard (DCB115) | 1.25–2A | ~90 min | ~110 min | ~165 min | No |
| Fast fan-cooled (DCB118) | ~8A | ~60 min | ~60 min | ~90 min | Yes |
| 4-port fast (DCB1104) | 4× fast | ~60 min each | ~65 min each | ~90 min each | Yes |
If you only run XR 5.0 packs on a drill, the little DCB115 that came in your kit is fine. The minute you own a FlexVolt pack, get a DCB118 fan-cooled charger. Charging a 9.0Ah FlexVolt on a standard brick takes the better part of three hours — long enough that you'll run out of battery before the second one's ready. Crews running all day should look at the 4-port DCB1104 so a dead pack is never the thing holding up the job.
FlexVolt compatibility — the question we answer every single day
This deserves its own section because it's where the money gets wasted. Three rules cover almost every question that lands on our counter:
- FlexVolt pack → 20V MAX tool: yes. It fits, it runs, and you get huge runtime. It's just heavier than a 20V pack.
- 20V MAX pack → 60V FlexVolt tool: no. It won't power it, and on most 60V tools the 20V pack won't even physically seat. The tool is built for the longer FlexVolt foot.
- 20V MAX pack → 20V MAX tool: yes, obviously — compact, XR, and POWERSTACK are all interchangeable here.
One more that trips people up: the 120V MAX tools (like the big 12" FlexVolt miter saw) take two FlexVolt packs at once and wire them in series for 120V. You can't run those on a single pack of any size. And no, there's no adapter that turns a 20V battery into a 60V one — the voltage comes from how the cells are wired inside a FlexVolt pack, and a 20V pack simply doesn't have the cells for it.
How to pick, in five questions
- Do you own any 60V or 120V FlexVolt tools (or plan to)?
Yes → you need at least two FlexVolt packs. Keep reading for which size. No → skip FlexVolt entirely and go to question 2.
- What's the heaviest-drawing tool you run — a saw/grinder, or a drill/driver?
Saw or grinder → a FlexVolt 6.0 or 9.0, even for 20V use, because the runtime and low sag are worth it. Drill/driver/light only → XR 5.0 or POWERSTACK.
- Are you on a ladder, scaffold, or holding the tool overhead a lot?
Yes → pay up for POWERSTACK to save the weight on your wrist. No → a standard XR 5.0 is the value pick.
- Do you run all day or in short bursts?
All day → buy a DCB118 fast charger and a third pack before you buy a bigger battery. Short bursts → two packs and the kit charger are plenty.
- Is the 12.0Ah tempting you?
Only buy a FlexVolt 12.0 for stationary or floor-standing tools — table saws, big blowers, the 120V saw. On a handheld it's dead weight.
What to buy by trade and budget
| You are a… | Start with | Add next | Rough spend (open-box / retail) |
|---|---|---|---|
| DIYer / homeowner | 2× XR 5.0 (DCB205) + kit charger | 1× Compact 2.0 for the light stuff | $110–$170 / $260–$340 |
| Finish carpenter / electrician | 2× POWERSTACK 5.0 + 1× Compact 1.7 | DCB118 fast charger | $180–$260 / $400–$520 |
| Framer / remodeler (owns 60V saws) | 2× FlexVolt 9.0 (DCB609) | 1× XR 5.0 for the impact, DCB118 | $220–$320 / $450–$600 |
| Landscaper / property maintainer | 2× FlexVolt 12.0 (DCB612) for blower/trimmer | 1× FlexVolt 6.0 for handhelds | $280–$400 / $500–$680 |
| Serious shop / stationary tools | 2× FlexVolt 12.0 + DCB1104 4-port | Rotation of XR 5.0 for handhelds | $320–$460 / $600–$780 |
Buying an open-box or used DeWalt battery — what to check
A lot of what crosses our bench are open-box packs pulled from combo kits — somebody bought the kit for the drill and sold the spare battery. Those are a steal if they're genuine and healthy, and a headache if they're not. Open-box isn't the same as used, but either way a battery is a consumable electrical part, so we test every one before it goes on the shelf. Here's the checklist we run — and the same one you should run on anything you buy from a stranger online:
| What to check | How | Good | Reject if |
|---|---|---|---|
| Resting voltage | Meter across the terminals | 18.0–20.5V, cells balanced | Under 15V (deep-discharged), or cells more than 0.15V apart |
| Fuel gauge | Press the button | All LEDs light evenly and hold | First LED flashing fast, or no response |
| Terminal pins | Look at the contacts | Clean, flat, silver | Bent, corroded, pushed in, or burn marks |
| FlexVolt switch | Rock the pack onto a 20V and a 60V foot | Seats and reads voltage on both | Won't seat on 60V, or no click/reconfigure |
| Case & screws | Check seams and the Torx screws | Tight, factory-sealed, Torx | Cracked case, Phillips screws (counterfeit tell), missing screws |
| Date code | Read the label | Legible, within a sane age | No label, scrubbed serial, or clearly ancient |
That counterfeit tell is worth repeating: genuine DeWalt packs use Torx security screws and have brass inserts in the screw wells. If you see Phillips screws or the pack feels suspiciously light on a scale, walk away — the cheap cells inside won't hold voltage and can cook a tool's electronics.
Questions we get at the counter
Will a FlexVolt battery hurt my old 20V tools?
No. A FlexVolt pack runs at 20V in a 20V tool — same voltage the tool was designed for — it just carries a lot more energy. Your drill can't tell the difference except that it runs much longer. The only downside is weight and the pack hanging a little lower off the tool.
Can I use a regular 20V battery in a 60V FlexVolt tool if I only need it for a minute?
No, and it's not a "be careful" situation — it physically won't work. Most 60V tools won't even let a 20V pack seat on the rail, and the ones that mechanically fit still won't power up, because the tool needs 60V that a 20V pack can't produce. You need a FlexVolt pack for any 60V tool.
What's the real difference between POWERSTACK and XR, besides price?
POWERSTACK uses flat pouch cells instead of cylindrical cans. For the same amp-hours it's lighter, holds voltage better under heavy pull, and runs cooler, so it feels stronger on high-drain handhelds. XR stores the same energy for less money in a slightly heavier case. On a drill you may never notice; on an impact driver or a compact saw you will.
Why does my FlexVolt battery say two different amp-hour numbers?
Because it's two batteries in one. The higher number (say 9.0Ah) is its capacity at 20V; the lower one (3.0Ah) is its capacity at 60V. The stored energy — 180 watt-hours — is the same either way. The pack rewires its own cells depending on whether the tool asks for 20V or 60V.
Is it worth buying open-box DeWalt batteries, or is that asking for trouble?
It's worth it if the seller actually tests them. A good open-box pack is usually a kit pull or overstock and runs 40–60% under big-box retail. The risk is buying an untested or counterfeit pack that sags or dies early. Buy from someone who load-tests each unit and checks the serial, and you get a genuine pack at a real discount with no gamble.
In-Stock Tools Mentioned in This Guide
Inspected, verified, and ready to ship from Value Tools Co. Quantities are limited.
Value Tools Co stocks certified open-box and inspected pre-owned DeWalt 20V MAX, POWERSTACK, and FlexVolt batteries, chargers, bare tools, and combo kits — every pack load-tested and verified genuine before it ships — with nationwide delivery and local pickup at our Elk Grove, California showroom. Browse the full DeWalt Collection and our Power Tools Collection to build out your cordless kit, and if you're still deciding between platforms, our Milwaukee M18 battery guide and cordless vs. corded breakdown are worth a read before you commit.
