Yuasa Scooter STR12-BS YTX12-BS Battery 12 V 10 Ah, 151x88x131 mm, 180 A

Yuasa Scooter STR12-BS battery, YTX12-BS equivalent: 12V 10 Ah (10.5 Ah at 20 hours), 180 A cranking, positive on the left, 151 x 88 x 131 mm. Sealed maintenance-free VRLA, with applications table.

If the scooter struggles to start, the starter turns slowly or the dash goes dead when you press the button, the most likely cause is a worn-out battery. The Yuasa STR12-BS is the 12V 10 Ah battery of the Yuasa Scooter Series, the same product family as the YTX12-BS: same reference dimensions, same voltage and same polarity, ready to replace the original battery of many scooters and motorcycles.

What it is

It is a sealed, maintenance-free VRLA (valve-regulated) lead-calcium battery: no caps to open, no topping up and no acid leaks. The declared cranking current is 180 A (EN); capacity is 10 Ah at 10 hours and 10.5 Ah at 20 hours, as printed on the label. The manufacturer's filled weight is 4.0 kg.

Size and polarity: what to check

The dimensions are 151 x 88 x 131 mm (length x width x height; some retailers quote 150 x 87 x 130 mm) and the positive terminal is on the left (SX) looking at the battery from the terminal side. Before ordering, compare the code, dimensions and terminal position with the battery you are replacing: a battery compartment is often tight and reversed polarity does not let you connect the leads.

STR12-BS or YTX12-BS: what is the difference?

STR12-BS is the code Yuasa uses in the Scooter Series, while YTX12-BS is the code of the YTX series. Voltage, capacity, cranking current and polarity match. If the original battery is marked YTX12-BS, this is the equivalent battery.

When to replace it

A battery lasts a few years on average, but short frequent trips, long periods of standing, hard cold and a weak charging system wear it out faster. Typical signs are slow starting, lights that dim when you press the button and the need to recharge it often. If the battery is new but starting is still hard, also have the voltage regulator and alternator checked.

Fitting and tips

Switch off and take out the key. Disconnect the negative terminal first, then the positive; fit the new battery in reverse order, connecting the negative last, and tighten the terminals firmly without forcing them. Respect the polarity and make sure the battery sits firmly in its compartment. Take the old battery to a collection centre or to the retailer: do not throw it away with ordinary waste.

Which scooters and motorcycles

The table gathers the models this battery family (YTX12-BS) is listed for, according to catalogue data and retailer listings: open the table and look for make and model. Lists vary by year and version, so always check the code of the original battery.

Frequently asked questions

What size is the STR12-BS?

About 151 x 88 x 131 mm, 12V, 10 Ah capacity (10.5 Ah at 20 hours).

What is the difference from the YTX12-BS?

They are two codes of the same family: STR12-BS for the Yuasa Scooter Series, YTX12-BS for the YTX series, with the same main values.

Where is the positive terminal?

On the left (SX) looking at the battery from the terminal side.

What is the cranking current?

180 A (EN).

How do I check it is the right one?

Compare code, dimensions and terminal position with the original battery and check the applications table.