Best Car Batteries for Every Driver and Budget

I’ve swapped out more car batteries than I’d like to admit. Some on freezing mornings in parking lots, some in my garage on a lazy Saturday, and one time on the shoulder of I-70 with semis blowing past at 75 mph. After all that, I’ve got opinions.

Finding the best car battery isn’t as simple as grabbing whatever’s on the shelf at your local parts store. What works great in a Civic in San Diego won’t cut it for a diesel F-250 in Minnesota. Different climates, different engines, different electrical loads. It matters more than most people think.

Here’s something most battery reviews won’t tell you. Almost every car battery sold in the US comes from just three manufacturers — Clarios, East Penn, and Stryten. That DieHard at Advance Auto? Clarios. The EverStart at Walmart? Clarios. Interstate at Costco? Also Clarios. Same factories, different stickers on the case. But that doesn’t mean the batteries are identical. Each brand sets its own specs, quality controls, and warranty terms, so the name on the label still matters. Just maybe not for the reasons you’d expect.

I spent weeks testing and comparing eight brands that cover every budget and driving situation out there — from premium AGM units built to handle desert heat and sub-zero cold, down to budget picks that’ll quietly get you through five winters without any fuss. Each brand section below breaks down what makes them different, their best models by group size, and who they’re really built for.

• While you’re figuring out which battery to get, a jump starter or a set of jumper cables can keep you on the road. And once you’ve got your new battery installed, a good charger will help it last years longer.

Best Car Battery Brands of 2026

Before diving into the reviews, take a minute to figure out what your vehicle actually needs. Check your owner’s manual or the label on your current battery for three things: the group size (like 24F, 35, or H6), the battery type (flooded or AGM), and the minimum CCA rating. If you skip this step, even the best battery on this list won’t do you any good if it doesn’t fit your car. Not sure how to read those specs? I break it all down in our buying guide at the bottom of this page.

DieHard — Best Overall

DieHard is one of those brands that almost doesn’t need an introduction. Sears created it back in 1967, and at the time it produced 35 percent more usable starting power than anything else on the market. In 2019, Advance Auto Parts acquired the brand for $200 million, and that’s where you’ll find it now — at Advance and Carquest stores.

The current lineup has five tiers. DieHard Red is the entry-level option with a 1-year free replacement warranty — fine if you’re flipping a beater or just need something cheap to get through a season. Silver bumps that to 2 years and adds a bit more starting power. Gold is where things start to get interesting: it uses stamped grid technology that DieHard claims delivers nearly 3X more corrosion resistance, and comes with a 3-year free replacement. Then there’s Platinum, a flooded battery with a 4-year warranty aimed at vehicles with medium electrical loads. And at the top, Platinum AGM — also 4-year free replacement — built for power-hungry vehicles with AGM technology.

I’ll be straight with you. DieHard’s reputation took some hits after the ownership change. You’ll find people online who swear their old Sears-era DieHard lasted a decade, and their new one barely made it to two years. Some of that is fair. Some of it is just how batteries work — a DieHard in Phoenix will die faster than one in Portland, no matter what’s inside. What I can say is that the Gold and Platinum tiers still hold up well for most drivers. The Red and Silver? They’re budget products and they perform like budget products.

The reason DieHard gets the “Best Overall” badge here isn’t because it’s the most advanced battery on this list. It’s because the lineup covers everyone. Tight budget? Red. Need something solid for a daily driver? Gold. Got a truck loaded with accessories? Platinum AGM. That range is hard to beat from a single brand. And if something goes wrong, Advance Auto is everywhere — walk in, get it tested, get it swapped. No shipping, no hassle.

One thing worth knowing: DieHard AGM batteries are manufactured by Clarios, the same company behind a handful of other brands on this list. That doesn’t make them identical — DieHard sets its own specs and quality standards — but it’s good context to have when you’re comparing prices.

Optima — Best Performance

Optima is one of those brands you either swear by or argue about on forums at 2 AM. There’s no middle ground. And honestly? After spending time with their batteries, I get why people feel so strongly.

What makes Optima different from everything else on this list is SPIRALCELL Technology. Instead of flat plates stacked inside a box like every other battery, Optima winds two pure lead plates into tightly compressed spiral cells — six per battery. The result looks like a six-pack of jelly rolls stuffed into a case, and that’s actually what people call it. This design gives the battery more plate surface area in a smaller package, which means lower internal resistance, faster recharging, and up to 15 times more vibration resistance than a conventional battery. They use 99.99% pure virgin lead instead of recycled alloys, and the cases are made from virgin polypropylene — no reused plastics. The whole thing is sealed, spill-proof, and can be mounted in almost any position.

The lineup breaks down by color. RedTop is your starting battery — high CCA, strong burst of cranking power, built for daily drivers with stock electrical systems. The popular 34/78 RedTop pushes 800 CCA with 100 minutes of reserve capacity. If your vehicle has aftermarket audio over 250 watts, a winch, a snowplow, inverters, or just a pile of factory electronics, YellowTop is the one. It’s a dual-purpose deep-cycle battery that can handle heavy discharge and recharge cycles without falling apart. BlueTop is for marine and RV applications — dark gray case for starting, light gray case for deep-cycle. And then there’s the new OrangeTop, a lithium iron phosphate (LiFePO4) battery for powersports with built-in Bluetooth and a jump-start feature Optima calls CPR.

Warranty is 36 months free replacement on RedTop and YellowTop for consumer use. BlueTop gets 24 months. Buy a battery and an Optima 1200 series charger together from their site and they’ll tack on an extra year. One thing worth noting: the warranty is not transferable and only honored by the original retailer. If you’re buying on Amazon, make sure it says “Ships from and sold by Amazon.com” — third-party sellers may not be able to help you with warranty claims down the road.

Are they expensive? Yes. A RedTop will run you roughly twice what a mid-tier flooded battery costs. But the tradeoff is real — longer life, better vibration handling, no maintenance, and the kind of reliability that made the U.S. military spec them for tactical vehicles. If you’re building something, racing something, or just want to stop thinking about your battery for the next five years, Optima earns every dollar.

Odyssey — Best for Extreme Conditions

If Optima is the enthusiast’s battery, Odyssey is the one engineers argue about. Made by EnerSys — a company most regular drivers have never heard of but every fleet manager knows — Odyssey batteries use something called Thin Plate Pure Lead technology, or TPPL. The idea is simple: take 99% pure virgin lead, roll it into plates thinner than what anyone else uses, and pack more of them into each cell. More plates, more surface area, more power. Twice the power of conventional batteries, according to EnerSys. Three times the service life.

The numbers back that up. The Extreme series can push cranking pulses up to 2,700 amps for five seconds. That’s not a typo. It also handles 400 charge-discharge cycles at 80% depth of discharge, which puts it in a different league from most AGMs that start falling apart after shallow cycling. Temperature tolerance is equally brutal — rated from -40°F all the way to 140°F on standard models, and up to 176°F with a metal jacket. If you’re running a diesel truck through a North Dakota winter or sitting in Arizona summer traffic with the AC on full blast, this battery doesn’t blink.

Odyssey currently offers two main lines for automotive use. The Extreme series is the flagship — dual-purpose, massive CCA, deep-cycle capable, built for vehicles with serious electrical demands like winches, overlanding setups, high-powered audio, or emergency fleet vehicles. The Performance series is a step down in price but still uses the same TPPL technology, making it a solid pick for drivers who want Odyssey quality without the Extreme price tag. There’s also the new Evolution line with AGM2 technology that pushes cycle life up to 650 cycles at 80% DOD — mostly aimed at commercial fleets and heavy-duty trucks, but worth watching as it rolls out.

Warranty is 36 months free replacement for consumer automotive use. Design life is listed at 8 to 12 years, with real-world service life typically landing around 3 to 10 depending on how you treat it. Users who maintain proper charging habits regularly report 5 to 8 years. One caveat: Odyssey batteries like being charged correctly. They want AGM-compatible charging — bulk voltage around 14.4 to 14.7 volts, temperature compensated. Skimp on that, and you’re shortening the life of an expensive battery.

And expensive they are. Most Odyssey automotive sizes land somewhere in the upper $200s to $400+ range before core charges. They’re also harder to find than a DieHard or EverStart — you won’t see them on a shelf at Walmart. Amazon carries most sizes, and you can find them through specialty battery retailers and some O’Reilly locations. The price and limited availability keep Odyssey out of the mainstream, but for anyone running a diesel, an off-road build, a fleet vehicle, or anything that absolutely cannot afford a dead battery on a bad day — this is the one.

Interstate — Most Trusted by Mechanics

Interstate is the battery brand your mechanic actually uses. Not because someone’s paying him to say it — because he’s been installing them for 20 years and they don’t come back. Founded in 1952 when John Searcy started delivering batteries out of a red Studebaker pickup in Dallas, the company has grown into one of the largest battery networks in North America. They sell 19 million batteries a year through over 200,000 dealers, 300 distributors, and more than 200 Interstate All Battery Center retail stores. That kind of reach is almost unfair.

Here’s what’s interesting about Interstate though. They don’t actually make batteries. Never have. Interstate is a marketing, distribution, and quality control company that contracts manufacturing to partners like Clarios and Exide. They set the specs, they enforce the standards, and they handle the distribution. Think of them less like a factory and more like a very picky middleman with a nationwide warranty network. Whether that bothers you or not is a personal thing, but it clearly works — I’ve talked to dozens of independent mechanics over the years, and Interstate is the name that comes up more than any other. They keep recommending them decade after decade, and that kind of loyalty isn’t bought with marketing budgets.

The current lineup runs four tiers. The base MT (Mega-Tron) is an entry-level flooded battery with an 18-month warranty — a no-frills option for mild climates and simple vehicles. MTP (Mega-Tron Plus) steps up to 30 months and better starting power, making it the sweet spot for most daily drivers. Then there’s MTX, a premium flooded option that bridges the gap to AGM. And at the top sits the MTZ — an AGM battery built with Pure Matrix technology using 99.99% pure, non-alloy lead in ultra-thin plates. The MTZ comes with a 48-month free replacement warranty, Interstate’s longest.

The real killer feature with Interstate isn’t the battery itself. It’s the warranty infrastructure. Buy an Interstate anywhere — Costco, a local shop, an All Battery Center, Pep Boys — and if something goes wrong, you can walk into any authorized location in the country and get it handled. No receipt matching, no arguing about where you bought it. For people who travel a lot, run fleet vehicles, or just hate dealing with warranty headaches, that’s a big deal. Most other brands tie their warranty to the store where you bought it.

Interstate doesn’t try to be the flashiest battery on the market. No spiral cells, no extreme temperature marketing, no color-coded tops. What they offer instead is boring, dependable consistency backed by a distribution network nobody else can match. If you want a battery that just works, from a brand that every mechanic in America already trusts, Interstate is the safe bet.

ACDelco — Best OEM Quality

ACDelco is what comes in your GM vehicle from the factory. Chevy, GMC, Buick, Cadillac — every one of them rolls off the line with an ACDelco under the hood. That alone says something. GM has enough skin in the game to care about what battery goes into their trucks and SUVs, because a dead battery at 14 months means a warranty claim they have to eat. So when GM backs ACDelco as the only battery brand they recommend, it carries weight.

But ACDelco isn’t just for GM owners. Their batteries fit most makes and models, and the lineup is simple enough that you won’t get lost. Two main tiers: Silver and Gold. Silver — formerly called Advantage — is the budget-friendly flooded battery with an 18-month free replacement warranty. It’ll do the job for a basic commuter in a mild climate. Gold — formerly Professional — is where ACDelco gets serious. The Gold flooded line comes with around 30 months of coverage, while Gold AGM batteries push that to 36 to 42 months depending on the group size. Both lines are maintenance-free, 100% pressure tested against leaks, and built with lead-calcium grid technology for corrosion resistance.

The Gold AGM is the one worth paying attention to. It’s designed for modern vehicles with start-stop systems, heavy factory electronics, and higher electrical demands — think heated seats, lane assist cameras, infotainment systems, all running off one battery. If your car came from the factory with an AGM, this is the replacement that matches OE specs exactly. For GM owners specifically, that kind of direct compatibility means no surprises with the battery management system, no registration headaches, no warning lights on the dash after a swap.

Where to buy is easy. ACDelco batteries show up at GM dealerships, Walmart, Amazon, and a network of ACDelco Independent Service Centers. Pricing sits in the mid range — cheaper than Optima or Odyssey, roughly in line with DieHard Gold or Interstate MTP. The Silver line undercuts most competitors on price, though the shorter warranty reflects that.

The honest take: if you drive a GM vehicle, ACDelco Gold is probably the path of least resistance. It’s the battery GM engineered the car around. For non-GM owners, it’s still a perfectly solid option, but you’re not getting that factory-match advantage — and at that point, you might shop around. Where ACDelco really shines is in that sweet spot between factory quality and aftermarket pricing. You’re getting OE-grade engineering without paying dealer markup, and that’s a hard combination to argue with.

EverStart — Best Budget

EverStart is the battery aisle’s best-kept secret hiding in plain sight at Walmart. Most people walk past it assuming it’s a generic store brand that cuts corners to hit a low price. It’s not. EverStart batteries are manufactured by Clarios and East Penn — the same companies making DieHard, Interstate, Optima, and half the other names on this list. You’re often getting the same core battery with different branding and without the markup.

The lineup is straightforward. EverStart Value is the absolute bottom shelf — around $50 to $80 with a 1-year warranty. Fine for a mild climate beater you don’t plan on keeping long. Plus sits in the middle at $80 to $120 with a 2-year free replacement. And Maxx is the one most people should be looking at: $120 to $150 for a flooded battery with 3-year free replacement plus 2 additional years of prorated coverage, giving you 5 years of total protection. CCA ratings on the Maxx line range from 650 up past 800 depending on group size, with reserve capacities around 90 to 130 minutes. There’s also a Maxx AGM for around $150 to $170 — sealed, maintenance-free, designed for start-stop vehicles and heavier electrical loads.

Here’s where it gets wild. Some EverStart AGM batteries are manufactured in the same facilities, by the same companies, using the same technology as batteries that cost nearly twice as much from premium brands. I’ve pulled EverStart AGMs off the shelf and compared them side by side with their pricier counterparts — same case dimensions, same weight, same country of origin stamped on the label. Whether every model is identical inside is impossible to say, but the manufacturing overlap is real, and the performance I’ve seen backs it up.

The other thing EverStart has going for it is Walmart itself. There are roughly 4,700 stores across the US, and most of them have an Auto Care Center that will install your battery for free when you buy it there. Warranty claims are simple — walk in, they test it, and if it’s dead you walk out with a new one. No phone calls, no shipping, no waiting. For someone who doesn’t want to crawl under a hood or argue with a parts counter, that’s worth something.

The downside? You’re buying it at Walmart. The shopping experience is what it is. And while the Maxx line holds up well, the Value and Plus tiers are genuinely budget products with shorter lifespans and warranties to match. But if you grab an EverStart Maxx or Maxx AGM, you’re getting a battery built by the same people who build the expensive stuff — at a price that makes the expensive stuff hard to justify.

Duralast — Best Value

Duralast is to AutoZone what EverStart is to Walmart — the house brand. But where EverStart wins on raw price, Duralast wins on the balance between cost and quality. AutoZone doesn’t position these as budget batteries. They call them “Proven Tough” and market them as OE-replacement grade. Having put a few of them through their paces, I’d say that’s a fair claim for the Gold and Platinum lines.

Four tiers to know. Standard Duralast is the entry-level flooded battery with a 2-year free replacement warranty. Duralast Gold steps up to a premium flooded design with stamped grid technology for better corrosion resistance and a 3-year free replacement. Duralast Platinum is where things jump to AGM — sealed, spill-proof, two times the cycle life of conventional batteries, backed by a 4-year free replacement. And the newest addition, Platinum Elite, pushes that even further with improved internals specifically designed for start-stop vehicles, three times the cycle life, and a 5-year free replacement warranty. That’s the longest free replacement warranty from any store brand on this list.

The Gold is the sweet spot for most drivers. It costs less than a DieHard Gold or Interstate MTP for comparable specs, and the 3-year warranty is competitive with anything in its price range. If your car came with a standard flooded battery from the factory, this is a clean, no-drama replacement. The Platinum AGM is worth the upgrade if you drive something with heavy electronics, start-stop, or if you just want a battery you can forget about for a while. I’ve installed Platinum AGMs in vehicles with aftermarket audio setups and dash cams running 24/7, and they’ve handled the draw without complaint.

AutoZone’s store network is a big part of the equation here. With over 6,000 locations across the US, they’re easy to find, and most stores will test and install your battery for free. The warranty is nationwide too — doesn’t matter which AutoZone you bought it from. Walk into any location, they pull up the purchase, test the battery, and swap it if it’s dead. Quick, painless, no shipping involved.

Duralast doesn’t try to compete with Optima or Odyssey on raw performance. That’s not the game they’re playing. What they do well is offer a solid, reliable battery at a fair price, backed by a warranty and store network that make ownership easy. For the average driver who wants something better than the cheapest option but doesn’t need to overspend, Duralast Gold hits that mark about as well as anything out there.

Deka — Best Hidden Gem

Every other brand on this list buys batteries from someone else and puts their name on it. Deka is the someone else. Made by East Penn Manufacturing out of Lyon Station, Pennsylvania — the world’s largest single-site battery manufacturing facility — Deka is what happens when the actual factory decides to sell direct. East Penn has been building batteries since 1946. They’re family-owned, still independent, and they produce flooded, AGM, Gel, and EFB batteries all under one roof. Most people have never heard of them. Most people have been using their batteries for years without knowing it.

Here’s the thing. When you buy a NAPA battery, there’s a good chance it’s a Deka. O’Reilly’s Super Start Platinum? Rebranded Deka. Some EverStart models at Walmart? East Penn. Even certain DieHard AGMs have been traced back to East Penn’s Intimidator line. The company operates behind the scenes for half the auto parts industry, and when one major retailer switched their battery supply to East Penn, the defect rate dropped by 75 percent. That’s not marketing. That’s manufacturing quality showing up in the numbers.

The Deka automotive lineup covers everything from basic flooded batteries to their Ultimate series — a premium flooded design with all-weather protection built for extreme heat and cold — and their AGM line, which is sealed, maintenance-free, and handles deep cycling without complaint. They also make one of the few true EFB (Enhanced Flooded Battery) options on the American market, designed specifically for vehicles with start-stop systems. East Penn holds the highest UL Recycled Content Validation for batteries in the world at 98 percent recycled material, which matters if sustainability is something you think about.

I’ve pulled Deka batteries off the shelf next to their rebranded counterparts and found the same case design, same weight, same specs — just a different sticker and a lower price. The Deka Intimidator AGM in particular is a battery I’ve been impressed with. Strong cranking power, solid reserve capacity, and it holds up in vehicles with heavy electrical loads. It’s the kind of battery that people in the car audio community have quietly used for years because the performance is there without the premium brand markup.

The catch? Availability. You’re not going to walk into a Walmart or AutoZone and find a battery that says Deka on it. You’ll need to find an authorized distributor, a local battery shop, or order through a NAPA or O’Reilly knowing you’re getting an East Penn product underneath their label. That extra effort is why Deka gets the “Hidden Gem” badge. The battery itself competes with anything on this list. The brand awareness just hasn’t caught up yet. For anyone willing to look past the flashy names and buy from the people who actually build the things, Deka is a smart move.

How to Choose the Right Car Battery

Picking a brand is only half the decision. The other half is making sure you’re buying the right battery for your actual vehicle, your climate, and the way you drive. This section covers the four things that matter most: battery type, group size, CCA, and how weather plays into all of it.

Battery Types: Flooded vs AGM vs EFB

Most car batteries on the road today fall into one of three categories, and knowing which one your car needs will save you from an expensive mistake.

Flooded lead-acid is the traditional design. Liquid electrolyte sloshes around inside between lead plates. It’s cheap, it works, and it’s what most vehicles have used for decades. If your car came with a flooded battery from the factory, a flooded replacement will do fine. Brands like DieHard Gold, Interstate MTP, Duralast Gold, and EverStart Maxx all fall into this camp.

AGM — Absorbent Glass Mat — is the upgrade. Instead of free-flowing liquid, the electrolyte is held in fiberglass mats pressed against the plates. That makes AGM batteries sealed, spill-proof, vibration resistant, and capable of handling deeper discharge cycles without falling apart. They recharge faster, last longer, and perform better in temperature extremes. If your vehicle came with an AGM from the factory — and most cars built in the last five years or so with start-stop technology did — you should replace it with another AGM. Downgrading to flooded can cause charging issues and may disable some vehicle functions. Optima, Odyssey, DieHard Platinum AGM, Interstate MTZ, Duralast Platinum, and EverStart Maxx AGM are all AGM options.

EFB — Enhanced Flooded Battery — sits between the two. It’s a flooded battery with improved cycling capability, designed mainly for European start-stop vehicles that don’t require a full AGM. Deka is one of the few brands offering a true EFB option in the US market. If you’re not sure which type your car needs, check the label on your current battery or look it up in your owner’s manual.

Understanding Group Sizes

Group size is the battery’s physical footprint — length, width, height, and where the terminals sit. It’s standardized by the Battery Council International (BCI), and every car has a specific group size it’s designed to accept. Use the wrong one and the battery either won’t fit in the tray, won’t connect to the cables, or will rattle around loose under the hood.

The easiest way to find your group size is to look at the label on your current battery. It’ll say something like Group 24F, Group 35, 48/H6, or 51R. You can also find it in your owner’s manual, or punch your year, make, and model into any auto parts store website — they all have fitment tools that’ll tell you exactly what you need.

Here’s a quick reference for the most common group sizes and the vehicles that typically use them:

• Group 24/24F — Honda Civic, Accord, Toyota Camry, Corolla, many Lexus models
• Group 35 — Toyota RAV4, Subaru Outback, Forester, Nissan Sentra
• Group 47/H5 — Chevy Cruze, Malibu, Buick Encore, some VW and Audi
• Group 48/H6 — Chevy Silverado, Tahoe, GMC Sierra, Cadillac, many European cars
• Group 49/H8 — BMW, Mercedes-Benz, larger Audi, Volvo
• Group 51/51R — Honda CRV, Civic (older), Acura, Nissan, Mazda
• Group 65 — Ford F-150, Explorer, Lincoln, some Mercury
• Group 78 — Chevy Silverado (older), GMC, Buick, Cadillac (side terminals)
• Group 94R/H7 — Dodge Ram, Jeep Grand Cherokee, Chrysler

One thing to remember: a larger group size doesn’t automatically mean more power. CCA and reserve capacity depend on the battery’s internal design, not just how big the case is.

CCA and Reserve Capacity: What Actually Matters

CCA stands for Cold Cranking Amps — the amount of current a battery can deliver for 30 seconds at 0°F while maintaining at least 7.2 volts. In plain terms, it’s how hard the battery can push to turn over a cold engine. The higher the CCA, the more starting muscle you’ve got.

How much do you need? It depends on your engine and where you live. Most passenger cars run fine with 400 to 600 CCA. Trucks and SUVs with larger engines usually want 600 to 800. Diesel trucks often need 800 to 1,000 or more. If you live somewhere that sees sub-zero winters, err on the higher side — cold thickens your engine oil and slows the battery’s chemistry at the same time, creating a double hit on starting power.

Reserve Capacity is the other number worth paying attention to. It measures how many minutes a fully charged battery can deliver 25 amps before voltage drops below 10.5 volts. Translation: it’s how long your car can run on battery alone if the alternator dies, or how long you can sit in a parking lot with the radio and lights on before things go dark. If you run a power inverter for a laptop, tools, or camping gear, reserve capacity becomes even more important — that’s the number that tells you how long you’ve actually got. Higher RC is better if your vehicle has a lot of electronics or if you use accessories with the engine off.

Always match or exceed the CCA and RC that came with your factory battery. Going higher is fine. Going lower is asking for trouble on the first cold morning.

Climate Matters More Than You Think

Heat kills batteries. Cold exposes weak ones. Both extremes matter, but they attack the battery differently.

In hot climates — think Arizona, Texas, Florida — the heat accelerates the internal corrosion of the lead plates and evaporates the electrolyte in flooded batteries faster. A battery rated for 5 years in Michigan might only last 3 in Phoenix. If you live somewhere hot, AGM batteries hold up better because they’re sealed and resist evaporation. Brands like Odyssey and Deka with specific high-temperature engineering are worth considering.

In cold climates — Minnesota, North Dakota, upstate New York — the challenge flips. Your engine is harder to crank and the battery’s chemical reactions slow down, producing less current exactly when you need more. This is where CCA matters most. A battery with 500 CCA might start your sedan fine in September but leave you stranded in January. If you deal with real winter, aim for the highest CCA your group size offers and consider an AGM for its better cold-weather performance.

Moderate climates are the easiest — most batteries will perform fine for their rated lifespan. But even in mild areas, short trips and infrequent driving can kill a battery faster than temperature extremes. If your car sits for days between drives, a battery maintainer is a cheap insurance policy.