Honda SP 125 battery size, as printed in the maker's brochure, is a 12 volt unit rated 4 Ah, yet a few newer editions are listed with a 12V 5Ah unit. Since both ratings turn up for this bike, copy the details off the sticker on your own battery before you shop.
On this fuel injected 125, the battery feeds the self starter, the injection electronics, the digital console and the lamps. Trouble usually announces itself as a lazy crank on a chilly morning. Below: how to confirm your rating, how to change the unit, and how to order the right one.
SP 125 fitment card
- Front tyre
- 80/100-18 47P, tubeless
- Rear tyre
- 100/80-18 53P, tubeless
- Wheels
- 18 inch alloy, front and rear
- Tyre pressure (cold)
- Front 25 psi, rear 33 psi with rider only
- With pillion
- Front 25 psi, rear 41 psi
- Battery
- 12V 4Ah in the brochure; some newer listings show 12V 5Ah
SP 125 battery rating at a glance
| Detail | What we found |
|---|---|
| Voltage | 12V |
| Capacity in brochure | 4Ah |
| Capacity on some newer listings | 5Ah |
| Where to confirm | Sticker on the battery, owner's manual |
Ah stands for amp hours, roughly how much charge is stored. A 5Ah unit stores a bit more than a 4Ah one. If the new case fits your tray and its posts line up with the old ones, going up to 5Ah causes no trouble. Case dimensions matter more than the Ah figure.
Finding the honda sp 125 battery size on your bike
- Key off, bike parked upright on level ground.
- Remove the body cover hiding the battery; your owner's manual names the panel and the fastener.
- Note the voltage, capacity and model code printed on the battery case.
- If the print has faded, measure length, width and height with a tape.
- Note which end carries the red positive post.
A clear mobile picture of the sticker plus the post layout, shown at the counter, avoids almost every wrong purchase.
Warning signs from an ageing SP 125 battery
- Cranking sounds sluggish, or you hear only a click, after a night parked outside.
- The horn goes feeble, or the console blinks when you thumb the starter.
- Headlamp brightness drops at idle.
- Only the kick lever brings the engine to life.
- The case looks swollen or cracked, or a crusty deposit forms around the posts.
First clean both posts and snug the bolts; a loose lead can fake a dead battery. A bike left unused for a month may simply need charging, and the bike battery charger page explains small trickle units.
Swapping the battery on an SP 125
- Turn the key off and pull it out.
- Undo the black negative lead first, then the red positive.
- Release the retaining band and lift the old unit straight up, keeping it level.
- Wipe the tray clean and dry; look for green or white corrosion.
- Seat the replacement facing exactly as the old one did.
- Reconnect red first, black second. Snug the small bolts without stripping them.
- Refit the rubber boot, the band and the body cover.
Sealed batteries generally leave the counter charged, but ask the seller to put a tester on it before you pay. A tester shows in seconds whether it is fully charged.
Buying the right replacement
Request a sealed, maintenance free 12V unit that matches your old battery's capacity and case size, and mention it goes in a fuel injected 125 cc commuter with self start. Look at the manufacturing sticker; stock that has waited many months on a shelf may have lost charge. Hold on to the bill, because warranty claims go through the battery maker's dealers.
Lithium units weigh less but cost more and need a compatible charging circuit. See lithium batteries for bikes for the trade offs.
Battery care in heat and rain
High summer temperatures age a battery faster than winter mornings do, so shaded parking helps. Monsoon puddles can splash up to the battery bay, and after a ride through floodwater it pays to dry the posts. Going away for weeks? Pull the negative lead so the clock and any alarm cannot slowly drain it.
More on the SP 125 and other batteries
Tyre details for this bike live on SP 125 tyre size and SP 125 tyre pressure. For other motorcycles, open the bike battery hub; a close relative is covered on Honda Shine battery size. Keep in mind that two bikes from one maker can still use different cases, so always compare the sticker.
Questions owners ask
Which battery goes in a Honda SP 125?
A sealed 12V unit. The brochure says 4Ah, and some newer editions are listed at 5Ah. Your current battery's sticker settles it.
Is a 5Ah battery okay in place of 4Ah?
Yes, provided its case matches in size and the terminals line up with the leads. The charging system copes with the extra capacity.
Where does the SP 125 keep its battery?
Behind a body cover around the bike's midsection. Your manual shows which cover comes off.
What is the usual life of an SP 125 battery?
That varies with heat, how often you ride and how many short hops it does. Ask the workshop to put a tester on it during routine servicing whenever cranking sounds slow.
Why does my SP 125 battery keep draining?
Loose posts, an accessory like a mobile charger left plugged in, or a charging circuit fault. A mechanic can measure the charging voltage in minutes.