YTX4L-BS Battery vs. YTZ5S Battery: Equivalents and Replacements
YTX4L-BS and YTZ5S batteries are two very similar motorcycle/Powersports batteries used as small starting/cranking batteries for 50-125 cc gasoline engines.
While having practically the same physical dimensions and battery terminal type and orientation, YTX4L-BS and YTZ5S batteries feature different specifications. Also, with the introduction of new technologies like enhanced AGM and lithium batteries, capacities and cranking currents differ even more.
Published: October 3, 2022.
YTX4L-BS and YTZ5S Batteries Features and Specifications
YTX4L-BS and YTZ5S batteries feature the same dimensions and battery terminal type, and orientation.
The physical dimensions of the batteries are 4.4375 x 2.75 x 3.375 inches (~113 x 70 x 86 mm), with the positive battery terminal on the right side of the battery.
Note: some newer lithium batteries are offered with quadruple battery terminals, helping the users with the mounting.
The only actual difference is that YTX4L-BS batteries are considered "standard" starting/cranking batteries, and YTZ5S batteries are considered "high-performance" batteries.
However, this classification is not the strict one - some brands label their 4.4375 x 2.75 x 3.375 inches (~113 x 70 x 86 mm) batteries as both YTX4L-BS and YTZ5S batteries.
On average, the performances of these batteries are:
- YTX4L-BS battery: 3.0 Ah 10h capacity, 50 Amps CCA,
- YTZ5S battery: 4.0 Ah 10h capacity, 65 Amps CCA.
Note: lithium cranking YTX4L-BS and YTZ5S batteries have pushed CCA values to 75+ Amps (sometimes 150+ Amps), making this classification vague even more...
Lead-Acid vs. Lithium YTX4L-BS and YTZ5S Batteries
YTX4L-BS and YTZ5S batteries are offered as:
- Lead-Acid Flooded/Wet Batteries: older types of batteries that are being phased out by the Sealed Lead-Acid (SLA) batteries.
- Gel-Cell Lead-Acid Batteries: type of maintenance-free Sealed Lead-Acid batteries with good performances and often low self-discharge rate with the electrolyte in the form of the gel, hence the name. Gel-Cell batteries are spill-proof batteries and can be mounted in any position except upside down.
- AGM Lead-Acid Batteries: type of maintenance-free Sealed Lead-Acid batteries where the electrolyte is suspended in the Absorbent Glass Mat (AGM), hence the name. AGM batteries feature good performances and are spill-proof batteries that can be mounted in any position except upside down.
AGM YTX4L-BS and YTZ5S batteries are the most popular type of YTX4L-BS and YTZ5S batteries, used in motorcycles, snowmobiles, ATVs, power generators, etc.
Most AGM batteries are delivered with their electrolyte ready for use and already (almost) fully charged, but some models are delivered with their electrolytes in bottles.
When such batteries arrive, they must be carefully filled with the battery acid and activated. Personally, factory-activated AGM batteries are the way to go for most users, but those users concerned with the longevity of their batteries should go for batteries delivered with dry cells.
- Lithium Batteries are maintenance-free, spill-proof batteries that can be mounted in any position, feature excellent performances, and are protected by Battery Management Systems (BMS), which prevent unwanted events like overcharging, over-discharging, low/high temperature, and similar.
On average, lithium batteries are 2-3x lighter and have better cranking features, except when too cold or too warm - when too cold or too warm, BMS may disconnect the battery from the terminals in order to protect it.
The use of lithium YTX4L-BS and YTZ5S batteries allows the riders to save ~2 pounds of weight, which may increase the performance of the vehicle.
YTX4L-BS and YTZ5S Batteries Cross Reference Chart
YTX4L-BS and YTZ5S batteries are quite popular little batteries that pack a surprisingly strong punch, considering their size and weight - they are not toys, and they should not be treated as such!
The following cross-reference chart lists some of the most popular YTX4L-BS and YTZ5S batteries with their most important features and specifications:
| Model | 10h Capacity (Ah) | CCA (Amps) | Weight (lbs/kg) |
| AMPXell YTX4L-BS | 2.5 | 80 (Lithium) | 0.91 lbs; 0.41 kg |
| Banshee YTX4L-BS | 3.0 | 155 (?!) | 3.19 lbs; 1.46 kg |
| Caltric YTX4L-BS | 3.0 | 60 | 3.5 lbs; 1.58 kg |
| Casil YTX4L-BS | 3.0 | 50 | 2.65 lbs; 1.20 kg |
| Chrome YTX4L-BS iGel | 3.0 | 50 | 3.2 lbs; 1.45 kg |
| Energizer YTX4L-BS | 3.0 | 50 | 3.24 lbs; 1.47 kg |
| ExpertPower YTX4L-BS | 4.0 | 50 | 2.87 lbs; 1.30 kg |
| ExpertPower YTX4L-BS Gel | 4.0 | 140 (?!) | 2.86 lbs; 1.30 kg |
| Maxlithium YTX4L-BS | 2.5 | 150 (Lithium) | 1.34 lbs; 0.61 kg |
| Mighty Max YTX4L-BS | 3.0 | 50 | 2.93 lbs; 1.33 kg |
| Mighty Max YTX4L-BS Gel | 3.0 | 50 | 2.87 lbs; 1.3 kg |
| Mighty Max YTX4L-BS | 1.6 | 110 (Lithium) | 0.82 lbs; 0.37 kg |
| MMG YTX4L-BS | 3.0 | 50 | 2.9 lbs; 1.31 kg |
| MMG YTZ5S | 1.6 | 120 (Lithium) | 1.0 lbs; 0.45 kg |
| MMG YTZ5S Gel | 4.0 | 65 | 3.3 lbs; 1.49 kg |
| Moto Classic YTX4L-BS | 4.5 | 90 (?!) | 2.9 lbs; 1.31 kg |
| Neptune YTX4L-BS | 4.0 | 50 | 3.2 lbs; 1.45 kg |
| PowerStar YTX4L-BS | 3.0 | 50 | 3.25 lbs; 1.47 kg |
| PowerTex YTX4L-BS | 2.5 | 75 (Lithium) | 1.1 lbs; 0.5 kg |
| PowerTex YTZ5S | 2.5 | 90 (Lithium) | 1.2 lbs; 0.54 kg |
| Protek YTX4L-BS Gel | 4.0 | 50 | 3.0 lbs; 1.36 kg |
| Protek YTZ5S Gel | 4.0 | 65 | 3.0 lbs; 1.36 kg |
| Shotgun YTX4L-BS | 4.0 | 50 | - |
| SigmasTek YTX4L-BS | 3.5 | 50 | 3.17 lbs; 1.44 kg |
| TPE YTX4L-BS | 2.0 | 220 (Lithium) | 1.15 lbs; 0.52 kg |
| UpStart YTX4L-BS | 3.0 | - | - |
| Weize YTX4L-BS | 3.0 | 50 | 3.17 lbs; 1.44 kg |
| Yuasa YTX4L-BS | 3.0 | 50 | 3.4 lbs; 1.54 kg |
| Yuasa YTZ5S | 3.5 | 65 | 3.5 lbs; 1.58 kg |
| Zipp YTX4L-BS | 3.0 | 50 | 2.98 lbs; 1.35 kg |
Note: Amazon links ("Model" column) open in the new windows, feel free to check them for the most up-to-date offers and prices.
As one can see, the most popular chemistry is Absorbent Glass Mat (AGM), but lithium chemistry is gaining in popularity with technological advancements.
Note: some manufacturers claim very high CCA values, which we can't independently verify - those models have "(?!)" after their CCA values.
How To Charge YTX4L-BS and YTZ5S Batteries
When mounted in the vehicle, YTX4L-BS and YTZ5S batteries should be charged via the onboard battery charging system, if present.
When the batteries are charged in the workshop/garage, the batteries should be charged using battery chargers intended for the battery chemistry of the used battery.
Since the lead-acid YTX4L-BS and YTZ5S batteries feature a 10h capacity of ~3-4 Ah, they should be charged with 0.3-0.4 Amps currents using intelligent battery chargers that switch from the charging mode to the maintenance mode when the battery is fully charged.
Note: some batteries allow fast charging at a 0.5C rate, but not more than 30 minutes, to avoid overheating the battery.
Lithium YTX4L-BS and YTZ5S batteries can be recharged with much stronger currents, usually up to 1C, but this is individual for each battery. On average, lithium batteries will do just fine when being charged with 0.2-0.3C currents.
What Kills YTX4L-BS and YTZ5S Batteries?
YTX4L-BS and YTZ5S batteries may last up to 2 to 5 years, depending on the vehicle, maintenance, usage, and similar.
Note: sealed lead-acid and lithium batteries are maintenance-free batteries, i.e., there is no need to refill them with distilled water or anything similar. However, it is important to verify from time to time their contacts and, if they are not going to be used for some time, to charge them from time to time, especially lead-acid batteries.
Another reason why batteries in general die (not just YTX4L-BS and YTZ5S batteries) are overheating and operating at too low temperatures - so, if possible, keep your bikes and other vehicles in garages and during the summer, when not in use, at least in the shades.
Vibrations and mechanical impacts also shorten batteries' operating lifetime, although AGM and lithium batteries are built to withstand plenty of abuse - just don't overdo it.
So, treat your YTX4L-BS and YTZ5S batteries with respect, and they will serve You for a long time, especially models from the most reputable brands that have already been tested by countless users in many real-life situations ...