Battery Charts

John Deere Battery Size Chart 2026: Complete Group Guide

Official John Deere battery sizes by model: BCI group, part number, CCA, RC and Ah from Deere's battery guide and parts guides.

The John Deere battery size chart below comes straight from Deere's own paperwork, not from a reseller's lookup tool. We took the BCI group listing in the John Deere Batteries guide and matched it to the battery part numbers printed in Deere's replacement parts guides for popular lawn tractors, Gators and compact tractors. Use it to find the BCI group size, Deere part number, cold cranking amps (CCA), reserve capacity and terminal style before you buy. If you are in a hurry: most small lawn tractors take a group U1 battery, the larger X500 series takes a group 51, and recent Gator XUV models take a group 45.

Quick answer: common John Deere battery sizes

S240 and X350 lawn tractors: BCI U1, part TY25221B. 12 V, 350 CCA, 38 min reserve capacity, 30 Ah, U1 lug-post terminals.
X590 lawn tractor: BCI 51, part TY25876B. 12 V, 500 CCA, 75 min reserve capacity, 45 Ah.
Gator XUV825i S4 and XUV835E/M/R: BCI 45, part TY25881B. 12 V, 480 CCA, 65 min reserve capacity, 30 Ah.
1025R compact utility tractor: Deere lists part TA15224. That number is not in the 2021 battery guide, so match it through your dealer or the parts catalog.

The rest of this guide covers why the chart is built by BCI group, how to read each column, the full listing of every battery in Deere's guide, and the mistakes people make when swapping a battery in a Deere.

How we built this chart

We used two kinds of Deere documents. The first is the John Deere Batteries guide (2021 edition). It contains a "Batteries by BCI Group Listing" table with each battery's part number, voltage, CCA, reserve capacity, amp-hours, terminal type and product line. The second is Deere's model-specific replacement parts guides, the one-page sheets that list the oil filter, air filter, spark plug, blades and battery for one machine. Those tell you which part number a given model uses. Putting the two together gives the BCI group and the electrical ratings for that model.

We did not use third-party fitment databases, because they often generalize across serial-number breaks. Where Deere's own documents disagree or leave a gap, we say so in the notes section rather than guessing.

John Deere battery size chart by model

These are the models whose official parts guides we checked. The group size comes from matching the listed part number to the BCI listing in the battery guide.

Model	Deere battery part	BCI group	Source
S240 lawn tractor (42/48 in Accel Deep deck)	TY25221B	U1	Deere parts guide
X350 lawn tractor (42/48 in deck)	TY25221B	U1	Deere parts guide
X590 lawn tractor (48/54 in deck)	TY25876	51	Deere parts guide
Gator XUV825i S4	TY25881	45	Deere parts guide
Gator XUV835E/M/R 4x4 (S/N -040000)	TY25881	45	Deere parts guide
1025R compact utility tractor	TA15224	not listed in 2021 guide	Deere parts guide

Two of the guides list a serial-number range or a deck option next to the model name, and we kept those labels exactly as Deere prints them. If your machine falls outside a listed serial range (for example a newer XUV835 built after S/N 040000), check the parts guide for your serial number before buying. Deere does change batteries between production runs, and the most common change is a move to a higher-CCA part in the same group.

Cranking power at a glance: lawn, garden and Gator batteries

The chart below plots CCA for the batteries in the groups used by Deere's lawn and garden tractors and its utility vehicles. Orange bars are Deere's StrongBox Original Equipment line. Dark bars are the cheaper Standard-Duty alternatives in the same group.

John Deere lawn, garden and Gator battery CCA by BCI group — CCA for Deere batteries in groups U1, 22NF, 45, 51 and 51R. Source: John Deere Batteries guide, 2021.

Three things stand out:

The U1 gap is small. The Original Equipment U1 (TY25221B) has 350 CCA and the Standard-Duty U1 (TY25878B) has 300 CCA. Both fit the same tray. The OE battery gives a bit more margin for cold starts and for a tractor that sits all winter.
Group 51 is a big jump. TY25876B gives 500 CCA from a case only slightly larger than a U1 in footprint. That is why bigger-engined X500 machines use it.
Group 45 is the Gator battery. The XUV825i and XUV835 use TY25881B with 480 CCA, close to the group 51 but in a different case and terminal arrangement. The two are not interchangeable even though the numbers look alike.

Battery dimensions for the common lawn groups

A battery that is electrically right but physically wrong will not hold down properly, and a loose battery in a vibrating mower fails early. Here are the outer case dimensions Deere gives for the groups you will see most on residential equipment:

BCI group	Typical Deere use	Length x width x height (mm)	Inches (approx.)
U1	S100/S200 series, X300 series lawn tractors	197 x 132 x 186	7.75 x 5.19 x 7.31
51 / 51R	X500 series, larger garden tractors	238 x 127 x 222	9.38 x 5.00 x 8.75
45	Gator XUV825i, XUV835	238 x 140 x 229	9.38 x 5.50 x 9.00

Measure your tray before buying, especially if a previous owner may have fitted something odd. A group 51R has the same footprint as a 51 but reversed terminal positions. The R means the positive and negative posts swap sides. On a tight battery box the cables may not reach the reversed posts. Kubota compacts show the same trap: our Kubota tractor battery size chart lists a Group 26R for the BX series and a Group 51R for the B and LX compacts.

The full John Deere battery listing by BCI group

This is the complete BCI group listing from the 2021 John Deere Batteries guide, covering lawn and turf, utility vehicles, compact tractors, ag tractors and construction machines. The terminal column uses Deere's codes: SAE post (standard tapered automotive post), threaded stud, U1 lug post (the small bolt-through terminals on mower batteries) and side terminal.

BCI group	Deere part	Volts	CCA	RC (min)	Ah	Terminal	Product line
1	TY21731B	6 V	640	130	90	SAE post	Standard-Duty
3EH	TY21737B	6 V	850	250	168	SAE post	Original Equipment
3ET	TY24341B	12 V	620	120	72	SAE post	Original Equipment
3ET	TY27794B	12 V	460	120	70	SAE post	Standard-Duty
4	TY21734B	6 V	975	250	125	SAE post	Original Equipment
4D	TY21754B	12 V	1050	290	135	SAE post	Original Equipment
4D	TY23020B	12 V	1400	410	190	SAE post	Original Equipment
4DLT	TY24381B	12 V	1000	220	132	SAE post	Original Equipment
4DLT	TY27829B	12 V	860	235	120	SAE post	Standard-Duty
5D	TY23025B	6 V	1000	300	180	SAE post	Original Equipment
5D	TY27793B	6 V	880	250	130	SAE post	Standard-Duty
8D	TY21748B	12 V	1400	440	195	SAE post	Original Equipment
22F	TY6192B	12 V	425	65	35	SAE post	Standard-Duty
22NF	TY26498B	12 V	500	75	45	SAE post	Original Equipment
22NF	TY27798B	12 V	360	58	35	SAE post	Standard-Duty
24	TY21764B	12 V	550	90	50	SAE post	Original Equipment
24F	TY27799B	12 V	700	120	70	SAE post	Truck/SUV
26R	TY27800B	12 V	540	80	50	SAE post	Standard-Duty
27	TY25272B	12 V	675	120	65	SAE post	Original Equipment
27	TY27805B	12 V	600	150	80	SAE + threaded	Standard-Duty
27F	TY24394B	12 V	710	120	65	SAE post	Truck/SUV
30H	TY21741B	12 V	650	150	65	SAE post	Original Equipment
31	TY25803B	12 V	760	170	90	SAE post	Original Equipment
31	TY25879B	12 V	950	175	90	SAE post	Original Equipment
31	TY27796B	12 V	925	170	90	SAE post	Standard-Duty
31T	TY24546B	12 V	950	175	90	Threaded stud	Original Equipment
31T	TY27795B	12 V	925	170	90	Threaded stud	Standard-Duty
34	TY26442B	12 V	800	115	65	SAE post	Original Equipment
34	TY27797B	12 V	690	110	60	SAE post	Standard-Duty
45	TY25881B	12 V	480	65	30	SAE post	Original Equipment
47/H5	TY27472B	12 V	650	100	60	SAE post	Original Equipment
48/H6	TY27473B	12 V	730	115	70	SAE post	Truck/SUV
49/H8	TY27474B	12 V	900	150	80	SAE post	Standard-Duty
51	TY25876B	12 V	500	75	45	SAE post	Original Equipment
51	TY27806B	12 V	425	70	40	SAE post	Standard-Duty
51R	TY27831B	12 V	500	75	45	SAE post	Original Equipment
65	TY24932B	12 V	850	150	80	SAE post	Truck/SUV
75	TY24944B	12 V	650	90	58	Side terminal	Truck/SUV
78DT	TY24937B	12 V	800	115	65	SAE + side	Truck/SUV
94R/H7	TY27804B	12 V	790	130	80	SAE post	Truck/SUV
D1	TY26773B	12 V	800	180	110	SAE post	Original Equipment
D4	TY26782B	12 V	1150	300	154	SAE post	Original Equipment
D5	TY26783B	12 V	1400	380	180	SAE post	Original Equipment
GCH2	TY27365B	6 V	N/A	N/A	255 (20-hr)	Ref.	Original Equipment
U1	TY25221B	12 V	350	38	30	U1 lug post	Original Equipment
U1	TY25878B	12 V	300	34	25	U1 lug post	Standard-Duty

Two practical notes on the listing. First, several groups have both an Original Equipment and a Standard-Duty option. They share a case size, so the swap is mechanical but not electrical: the Standard-Duty part usually has lower CCA and a shorter warranty. Second, the 6-volt batteries (groups 1, 3EH, 4, 5D and GCH2) are used in pairs, wired in series, on older and larger machines. Never put a single 6-volt battery into a 12-volt system or the other way round.

How to read each column

BCI group size

The Battery Council International group number sets the case dimensions, terminal position and terminal type. It is the first thing to match, because it decides whether the battery physically fits. If you want the background on how group numbers work across cars and equipment, see our explainer on battery group sizes.

Cold cranking amps (CCA)

CCA is the current a fully charged battery can deliver at 0 °F (-18 °C) for 30 seconds while staying above 7.2 volts on a 12-volt battery. It is the best single number for starting ability in cold weather. A lawn tractor single-cylinder or V-twin needs much less than a diesel compact tractor, which is why the chart goes from 300 CCA on a U1 to 1,400 CCA on a 4D or D5 battery.

Reserve capacity (RC) and amp-hours (Ah)

Reserve capacity is how many minutes the battery can supply 25 amps before dropping to 10.5 volts. Amp-hours measure total stored energy. On a mower, these numbers matter if you run lights or attachments with the engine off, or if the charging system is weak. The difference between the three ratings is explained in our CCA vs RC vs Ah guide.

Terminal type

U1 mower batteries use small lug-post terminals with a nut and bolt through the cable eye. Automotive-style groups use SAE tapered posts. Some heavy batteries offer both SAE posts and threaded studs. If your cable ends are ring terminals, a battery with only SAE posts will need adapters.

Choosing a replacement battery for your John Deere

Find your model and serial number. They are on the frame tag. On most lawn tractors it sits below the seat or near the left rear wheel.
Look up the battery part number in Deere's replacement parts guide for that model, or in the chart above.
Translate it to a BCI group using the full listing. This is what lets you shop non-Deere brands if you want to.
Match or exceed the CCA. Going higher is fine. Going lower costs you cold-start reliability. See whether a higher CCA battery is better for the details.
Check the terminal layout and orientation against the old battery before you remove it. Take a photo.
Decide on the battery type. Deere's lawn batteries are generally conventional flooded or maintenance-free designs. If you are thinking about an AGM upgrade, read whether you can replace a flooded battery with AGM first.

Common mistakes when buying a mower or tractor battery

Buying by voltage alone. "12 volt mower battery" covers everything from a 200 CCA U1 to a group 51 with more than twice the capacity. Match the group.
Ignoring the R suffix. 51 and 51R are the same size with mirrored terminals. The wrong one can stretch or short a cable.
Using a car battery in a lawn tractor. It will not fit the tray. Tying it down with straps is a vibration and short-circuit risk.
Assuming the Gator battery fits the X590. Group 45 and group 51 have similar CCA but different case widths.
Storing a new battery discharged. Lawn batteries lose charge over winter. Use a maintainer or remove the battery and keep it charged.

Installing the battery safely

Turn the key off and remove it. Disconnect the negative (black) cable first, then the positive (red), and lift the old battery out using the hold-down as a guide. Clean any corrosion from the cable ends with a baking-soda solution and a wire brush. Set the new battery in the same orientation, fit the hold-down, and connect the positive cable first, then the negative. Tighten the lug bolts snugly without overtightening the small U1 posts, and refit any terminal cover. If the battery shipped dry or partially charged, fully charge it before the first start. A low battery makes the starter work harder and can hide charging problems.

If your new battery keeps going flat, the battery is rarely the cause. Check for a dirty or loose ground connection, a parasitic drain from aftermarket lights, or a failed charging regulator. Most lawn tractor charging systems put out only a few amps, so short mowing sessions after long storage may never fully recharge a weak battery.

Notes, gaps and inconsistencies in Deere's data

Part number suffixes: the battery guide uses a trailing B (TY25876B), while some parts guides print the number without it (TY25876). We treated these as the same battery. Your dealer can confirm the current superseding number.
1025R: the parts guide lists TA15224, which does not appear in the 2021 battery guide, so we do not assign a group here. Confirm the group with your dealer.
Minor figure differences: within the battery guide, the group 31 Original Equipment battery TY25803B shows 85 Ah in one table and 90 Ah in the BCI listing. Some 5D case lengths also differ slightly between tables. The CCA figures we rely on above are consistent.
Edition: the guide is the 2021 edition. Newer machines and superseded part numbers may not be included.

Frequently asked questions

What size battery does a John Deere lawn tractor take?

Most small John Deere lawn tractors, including the S240 and X350, use a BCI group U1 battery, Deere part TY25221B: 12 volts, 350 CCA, 30 Ah, with U1 lug-post terminals. Bigger garden tractors such as the X590 move up to a group 51 battery (TY25876B, 500 CCA).

What battery does a John Deere Gator XUV825i or XUV835 use?

Deere's parts guides list battery TY25881 for the XUV825i S4 and the XUV835E/M/R. In the battery guide that is a BCI group 45 battery with 480 CCA, 65 minutes of reserve capacity and 30 Ah.

Can I use a car battery in my John Deere lawn tractor?

Usually no. A U1 tray is about 197 x 132 x 186 mm (7.75 x 5.19 x 7.31 in). Car groups like 24 or 34 are much bigger and won't fit the tray or hold-down. Keep to the BCI group shown on the chart for your model.

Is it OK to use a higher CCA battery than the original?

Yes, as long as the BCI group, voltage and terminal layout match. Higher CCA only means more cranking reserve. The starter draws what it needs.

What does the B at the end of a John Deere battery part number mean?

The part numbers in Deere's 2021 battery guide end in B, for example TY25221B. Parts guides for individual machines often leave it off and print TY25221 or TY25881. Treat both forms as the same battery family, then check the group, CCA and terminals.

What is the difference between a group 51 and 51R battery?

They have the same case size, but the terminals are mirrored. On a 51R the positive and negative posts are on opposite sides from a 51. Deere lists TY25876B as a 51 and TY27831B as a 51R, both rated 500 CCA.

Which is better for my mower, TY25221B or TY25878B?

Both are U1 batteries that fit the same tray. TY25221B is Deere's Original Equipment battery with 350 CCA and 30 Ah. TY25878B is the Standard-Duty option with 300 CCA and 25 Ah. Choose the OE battery for cold starts or long storage.

How long does a John Deere lawn tractor battery last?

Typically three to five years, depending on climate, how often it is used and how it is stored over winter. Keeping it on a maintainer during storage is the biggest single factor in battery life.