SAE, DIN, EN or JIS? Identify Your Battery Post in 30 Seconds
Two checks with your eyes, and one decision that actually changes what you can order.
Look at the top of your battery. If you see two round tapered posts, one clearly fatter than the other, you have SAE, DIN or EN — and our terminals fit all three. If the posts are thin and stalk-like, or if the connections are on the side of the case rather than the top, ours will not fit. That is the whole decision.
Why this is a shorter question than it looks
Battery post standards get written up as a four-way comparison — SAE, DIN, EN, JIS — which makes it sound like you need to identify exactly which one you have before ordering anything.
For our terminals you do not. They are cut to fit the tapered top posts used by SAE, DIN and EN batteries, which covers the overwhelming majority of cars, trucks, RVs, boats and motorcycles sold in North America and Europe. So the only identification that changes your decision is: is it a tapered top post, or is it something else?
We would rather tell you that plainly than walk you through a specification table you do not need.
Check 1: where are the connections?
Open the hood and look at the battery.
- Two round posts rising from the top surface → top post. Continue to check 2.
- Two threaded holes in the side of the case, usually recessed → side post. Common on GM vehicles. Standard top-post terminals do not fit. You need a modular head.
- Threaded studs sticking up, often with nuts already on them → stud terminals. Common on marine, deep-cycle and some AGM batteries. Also needs a modular head.
- Both — a top post and a side connection → dual-terminal battery. Use whichever you are actually wiring to.
Check 2: are the posts tapered, or thin and straight?
This is the one that matters, and it takes about five seconds.
A tapered automotive post is a truncated cone: noticeably wider where it meets the battery case than at the top. It is chunky — you would not describe it as a pin. The positive post is visibly fatter than the negative, which is how a terminal cannot be fitted to the wrong side by accident.
A JIS post — sometimes called a pencil post — is thinner, and the difference is obvious once you have seen both. These are common on Japanese-market vehicles and on smaller batteries. Our terminals do not fit JIS posts. Not "fit tightly", not "fit with an adapter" — they do not fit, and you should not order one expecting it to work.
The thirty-second version
Put a finger on the positive post. If it feels like a substantial cone you could not fully cover with a fingertip, it is SAE / DIN / EN and our terminals fit. If it feels like a slim stub, it is likely JIS and they do not.
Check 3: SAE, DIN or EN — does it matter?
For fitment on our terminals, no. All three are tapered top posts within the range our clamping faces are machined for.
It matters for one reason only: post diameters differ slightly between the standards, so a terminal cut for one and used on another makes contact along a line rather than across a face. That is the single most common cause of a terminal that will not stay tight — and it is why we machine the clamping surface rather than casting it. The full explanation is here.
If you want to know which standard you have for other reasons, the practical checks are:
- Where the battery was sold. North American replacement batteries are typically SAE. European are typically DIN or EN.
- The group size printed on the label. BCI group numbers (24, 34, 35, 48, 65 and so on) indicate a North American battery. European batteries carry an ETN or DIN part number instead.
- Measure the top diameter of the positive post and compare it against the published figures for each standard. Published post dimensions vary slightly between sources, so treat a borderline measurement as inconclusive rather than definitive.
Polarity: do not guess
Positive is the larger post, and it is normally marked with a + moulded into the case, often with red. Negative is smaller, marked −, often black.
Do not rely on cable colour. Cables get replaced, and they get replaced by people who used whatever was on the shelf. The moulding in the plastic case is the reliable marker; the wire is not.
If you are using colour-anodised terminals, the red one goes on positive and blue on negative — which is the entire point of the colour, and a genuinely useful safeguard when you are working in a dark engine bay at an awkward angle.
Summary table
| What you see | Post type | Fits our terminals? |
|---|---|---|
| Two tapered round posts on top, positive clearly fatter | SAE / DIN / EN | Yes — any series |
| Two thin, straight, stalk-like posts on top | JIS pencil post | No |
| Threaded holes in the side of the case | Side post | Modular head only |
| Threaded studs with nuts | Stud terminal | Modular head only |
Once you know your post type, the next two questions are how many cables you need to land and whether the terminal will physically fit the space.
How many ways do you need? → Clearance dimensions →
Free: Battery Terminal Fitment & Torque Guide
Post identification chart, clearance dimensions for every terminal, torque table, and a print-to-scale paper template you can hold in your engine bay before you order.
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