Yuasa Motorbike battery YTX4L-BS / YTX4L 12V 3Ah (3.2Ah) (AGM maintenance-free)
Product information
The Yuasa YTX4L-BS (often also referred to as YTX4L) is a very compact and lightweight AGM battery, specially developed for modern 50cc scooters, mopeds and small dirt bikes. With a capacity of 3 Ah (10h) or 3.2 Ah (20h) and a cold start current of 50 A (EN), it reliably supplies power for the electric starter of small engines. It is the modern, maintenance-free standard that has replaced older wet batteries in many current vehicles.
Highlights at a glance
- The standard for 50cc scooters: The most widespread battery size for modern 50cc scooters (4-stroke and 2-stroke) as well as small enduros (e.g. KTM 50 SX).
- Compact format: At only 86 mm high, it is extremely flat and also fits in very tightly built battery compartments under the footboard or seat bench.
- AGM technology: The acid is immobilised in the glass mat (Absorbent Glass Mat), which makes the battery leak-proof, vibration-resistant and cycle-resistant – ideal for the "stop & go" in city traffic.
- Maintenance-free: Thanks to VRLA technology (valve regulated), the system is hermetically sealed after the first filling; topping up with water is not necessary and not possible.
- Reliable starting: Despite its small size, it delivers 50 A starting current, which is completely sufficient for small displacements.
- Long lifespan: The robust Yuasa construction forgives occasional periods of non-use better than cheap no-name products, provided it is not deeply discharged.
The standard for Honda, KTM & Kymco
The YTX4L-BS is the original equipment for countless vehicles. It can be found in almost all Kymco 50cc scooters, many Honda scooters (e.g. Vision 50), Peugeot scooters (newer models) and KTM kids' cross bikes. It is the perfect choice for riders who want a hassle-free battery: fit and forget (until winter).
Characteristics
| Model | Yuasa YTX4L-BS (Maintenance Free) |
| Application | 50cc scooters, mopeds & sport enduros (e.g. KTM EXC 2-stroke) |
| Technology | AGM (VRLA) - dry pre-charged (incl. acid pack) |
| Voltage | 12 V |
| Capacity | 3 Ah (10 h) / 3.2 Ah (20 h) |
| Cold start current (CCA) | 50 A (EN) |
| Dimensions (L x W x H in mm) | 114 x 71 x 86 (compact size) |
| Pole arrangement | 0 (positive terminal right) |
| Terminal type | Type 5 (front/top mounting) |
| Base strip | N (no base strip) |
| Special features | Tip-over protection up to 45° (after filling), maintenance-free, lightweight |
| Weight (kg) | approx. 1.4 (filled) |
FAQs about the Yuasa YTX4L-BS
What is the difference to the YB4L-B?
This is the most important point!
- YTX4L-BS (your battery): 86 mm high (AGM, maintenance-free).
- YB4L-B (old standard): 93 mm high (acid, requires maintenance). The YTX4L-BS is flatter. You can often use the YTX4L-BS as a replacement for the YB4L-B (possibly pad underneath so it doesn't wobble), but conversely, the taller YB4L-B often won't fit into scooters built for the flat YTX4L-BS.
What is the difference to the YTX5L-BS?
The base area is identical (114 x 71 mm), but the height is different.
- YTX4L-BS: 86 mm high (3 Ah).
- YTX5L-BS: 106 mm high (4 Ah). The YTX5L has more power, but is 2 cm taller. Before buying, check whether your battery box has 2 cm of extra room above. If so, the 5L is a great upgrade. If not, you must stick with the 4L.
Do I need to charge the battery?
Yes, absolutely. As the battery is very small, the ratio of acid volume to lead is sensitive. After filling (with BS version), it is about 75% charged. Charge it fully with a suitable charger (max. 0.3 - 0.4 ampere charging current) before installation to achieve full lifespan.
Can I install it lying down?
The YTX4L-BS is an AGM battery and thus leak-proof. Many modern scooters (e.g. Honda) install this battery lying under the footboard. This is permissible provided the battery has been correctly sealed with the seal after activation.
| Capacity: | 3.2Ah |
|---|---|
| Tension: | 12V |
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