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EFB Automotive Batteries
 auto batteries for cars with start-stop system.jpg "Western EFB ADVANCE (Enhanced Flooded Battery) auto batteries for cars with start-stop system.jpg")
EXTRA POWER FOR PREMIUM PERFORMANCE
Built on advanced EFB (Enhanced Flooded Battery) technology for high performance and long life, the Western Electrical EFB ADVANCE battery series delivers outstanding starting power and consistent power output over extended periods.
Designed to meet the specialized power requirements of modern vehicles, these batteries incorporate industry-leading design features and are manufactured in accordance with the latest production methods and quality controls, achieving unmatched energy recovery and exceptional dynamic charge acceptance. This gives the series the ability to support all vehicles, with or without start-stop systems
SPECIFICATIONS
JIS StandardJapanese standard specification tableDIN StandardGerman standard specification tableBCI StandardAmerican standard specification table
JIS StandardTech DrawingFAQs
| Serial No. | Size Group | Battery Model No. | Voltage | Capacity | RC | CCA | Dimension (mm±2) | Cell Layout (Polarity) | Terminal Type | Base Hold Down | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (V) | Ah(@20HR) | (min) | A(@-18°C) | L | W | H | TH | ||||||
| 1 | B20 | EFB-M42 | 12 | 40 | 62 | 420 | 195 | 128 | 200 | 221 | 0 (- +) | B(Small) | B0 |
| 2 | B20 | EFB-M42R | 12 | 40 | 62 | 420 | 195 | 128 | 200 | 221 | 1 (- +) | B(Small) | B0 |
| 3 | B24 | EFB-N55 | 12 | 55 | 78 | 520 | 237 | 127 | 201 | 222 | 0 (- +) | A | B0 |
| 4 | B24 | EFB-N55R | 12 | 55 | 78 | 520 | 237 | 127 | 201 | 222 | 1 (- +) | A | B0 |
| 5 | B24 | EFB-N55S | 12 | 55 | 78 | 500 | 237 | 127 | 201 | 222 | 0 (- +) | B(Small) | B0 |
| 6 | D23 | EFB-Q85 | 12 | 65 | 114 | 680 | 231 | 172 | 201 | 222 | 0 (- +) | A | B1 |
| 7 | D23 | EFB-Q85R | 12 | 65 | 114 | 680 | 231 | 172 | 201 | 222 | 1 (- +) | A | B1 |
| 8 | D26 | EFB-S95 | 12 | 75 | 137 | 780 | 259 | 174 | 201 | 222 | 0 (- +) | A | B1 |
| 9 | D26 | EFB-S95R | 12 | 75 | 137 | 780 | 259 | 174 | 201 | 222 | 1 (- +) | A | B1 |
| 10 | D31 | EFB-T115 | 12 | 90 | 160 | 880 | 305 | 174 | 201 | 222 | 0 (- +) | A | B1 |
| 11 | D31 | EFB-T115R | 12 | 90 | 160 | 880 | 305 | 174 | 201 | 222 | 1 (- +) | A | B1 |
| 12 | E41 | EFB-E41-100 | 12 | 110 | 208 | 1000 | 406 | 173 | 205 | 227 | 1 (- +) | A | B0 |
Note:
1. In the Dimension columns: L = Length, W = Width, H = Height, TH = Total Height.
2. CCA (Cold Cranking Amps) rating is for reference only. CCA is a theoretically calculated average value. Actual performance may vary due to test conditions and standards.
3. Due to the wide range of battery models, if the battery model you are interested in is not shown in the specification chart, please contact us.
4. The specifications are subject to update without notification for reasons of improvement.
5. For further detailed information, please visit our vertical automotive battery site: www.auto-battery.com
Terminal Type
Cell Layout (Polarity)
Base Hold Down
What does EFB mean on a car battery?
EFB stands for Enhanced Flooded Battery. It is an enhanced flooded lead-acid battery with improved charge acceptance and deeper cycle durability, developed as a cost-effective upgrade over conventional flooded batteries for vehicles with start-stop systems.
Which vehicles is the EFB JIS range designed for?
The JIS range covers B20 to E41 size groups, widely used in Japanese and Korean passenger cars and light commercial vehicles, including entry-level start-stop applications.
Can an EFB battery replace a conventional flooded battery?
Yes. With the same JIS size group, voltage and polarity, an EFB battery is a direct upgrade that delivers roughly twice the cycle life and better recovery from frequent engine starts.
How should an EFB battery be charged?
Use an automatic smart charger with a maximum charging voltage of 14.4 to 14.8 V at 25°C. Avoid chargers above 15 V, which can accelerate water loss in the flooded design.
DIN StandardTech DrawingFAQs
| Serial No. | Size Group | Battery Model No. | Voltage | Capacity | RC | CCA | Dimension (mm±2) | Cell Layout (Polarity) | Terminal Type | Base Hold Down | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (V) | Ah(@20HR) | (min) | A(@-18°C) | L | W | H | TH | ||||||
| 1 | LB1 | EFB-LB1-45 | 12 | 45 | 71 | 450 | 208 | 175 | 175 | 175 | 0 (- +) | A | B13 |
| 2 | L1 | EFB-L1-55 | 12 | 55 | 92 | 520 | 208 | 175 | 190 | 190 | 0 (- +) | A | B13 |
| 3 | LB2 | EFB-LB2-50 | 12 | 50 | 88 | 500 | 239 | 175 | 175 | 175 | 0 (- +) | A | B13 |
| 4 | L2 | EFB-L2-62 | 12 | 62 | 114 | 680 | 239 | 175 | 190 | 190 | 0 (- +) | A | B13 |
| 5 | LB3 | EFB-LB3-65 | 12 | 65 | 106 | 700 | 276 | 175 | 175 | 175 | 0 (- +) | A | B13 |
| 6 | L3 | EFB-L3-70 | 12 | 70 | 131 | 760 | 273 | 175 | 190 | 190 | 0 (- +) | A | B13 |
| 7 | LB4 | EFB-LB4-75 | 12 | 75 | 136 | 780 | 315 | 175 | 175 | 175 | 0 (- +) | A | B13 |
| 8 | L4 | EFB-L4-80 | 12 | 80 | 141 | 820 | 315 | 175 | 190 | 190 | 0 (- +) | A | B13 |
| 9 | LB5 | EFB-LB5-92 | 12 | 92 | 143 | 900 | 353 | 175 | 175 | 175 | 0 (- +) | A | B13 |
| 10 | L5 | EFB-L5-100 | 12 | 100 | 184 | 920 | 353 | 175 | 190 | 190 | 0 (- +) | A | B13 |
Note:
1. In the Dimension columns: L = Length, W = Width, H = Height, TH = Total Height.
2. CCA (Cold Cranking Amps) rating is for reference only. CCA is a theoretically calculated average value. Actual performance may vary due to test conditions and standards.
3. Due to the wide range of battery models, if the battery model you are interested in is not shown in the specification chart, please contact us.
4. The specifications are subject to update without notification for reasons of improvement.
5. For further detailed information, please visit our vertical automotive battery site: www.auto-battery.com
Terminal Type
Cell Layout (Polarity)
Base Hold Down
What is the difference between EFB and AGM batteries?
Both support start-stop vehicles. AGM offers higher cycle life for advanced start-stop systems with braking energy recovery, while EFB provides a reliable and more economical solution for entry-level start-stop applications.
Why do some DIN models have two heights, such as LB2 and L2?
In DIN naming, the B prefix indicates a low height of 175 mm and the plain L type is taller at 190 mm. The two variants share the same footprint and capacity, so you can choose according to the vehicle battery tray.
Are EFB batteries suitable for frequent short trips?
Yes. Enhanced charge acceptance allows the battery to recover quickly after each start, which makes EFB well suited to urban driving with frequent stops and short distances.
Are EFB batteries delivered charged and ready to install?
Yes. EFB batteries are wet-charged and activated before leaving the factory. After a simple voltage check, they can be installed and put into service directly.
BCI StandardTech DrawingFAQs
| Serial No. | Size Group | Battery Model No. | Voltage | Capacity | RC | CCA | Dimension (mm±2) | Cell Layout (Polarity) | Terminal Type | Base Hold Down | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (V) | Ah(@20HR) | (min) | A(SAE) | L | W | H | TH | ||||||
| 1 | BCI 51 | EFB-51 | 12 | 55 | 78 | 520 | 237 | 127 | 201 | 222 | 10 | A | B0 |
| 2 | BCI 51R | EFB-51R | 12 | 55 | 78 | 520 | 237 | 127 | 201 | 222 | 11 | A | B0 |
| 3 | BCI 25 | EFB-25 | 12 | 65 | 114 | 680 | 231 | 172 | 201 | 222 | 10 | A | B1 |
| 4 | BCI 35 | EFB-35 | 12 | 65 | 114 | 680 | 231 | 172 | 201 | 222 | 11 | A | B1 |
| 5 | BCI 24 | EFB-24 | 12 | 75 | 137 | 780 | 259 | 174 | 201 | 222 | 10 | A | B1 |
| 6 | BCI 24R | EFB-24R | 12 | 75 | 137 | 780 | 259 | 174 | 201 | 222 | 11 | A | B1 |
| 7 | BCI 27 | EFB-27 | 12 | 90 | 160 | 880 | 305 | 174 | 201 | 222 | 10 | A | B1 |
| 8 | BCI 27R | EFB-27R | 12 | 90 | 160 | 880 | 305 | 174 | 201 | 222 | 11 | A | B1 |
| 9 | BCI 31 | EFB-31 | 12 | 105 | 185 | 1050 | 330 | 172 | 218 | 242 | 18 | TOP | B1 |
| 10 | BCI 31 | EFB-31S | 12 | 105 | 185 | 1050 | 330 | 172 | 218 | 242 | 18 | STUD | B1 |
| 11 | BCI 31 | EFB-31DT | 12 | 105 | 185 | 1050 | 330 | 172 | 218 | 242 | 18 | DUAL | B1 |
| 12 | BCI 47 | EFB-47 | 12 | 62 | 114 | 680 | 239 | 175 | 190 | 190 | 24 | A | B13 |
| 13 | BCI 48 | EFB-48 | 12 | 70 | 131 | 760 | 273 | 175 | 190 | 190 | 24 | A | B13 |
| 14 | BCI 49 | EFB-49 | 12 | 100 | 184 | 920 | 353 | 175 | 190 | 190 | 24 | A | B13 |
| 15 | BCI 90 | EFB-90 | 12 | 50 | 88 | 500 | 239 | 175 | 175 | 175 | 24 | A | B13 |
| 16 | BCI 91 | EFB-91 | 12 | 65 | 106 | 700 | 276 | 175 | 175 | 175 | 24 | A | B13 |
| 17 | BCI 92 | EFB-92 | 12 | 75 | 136 | 780 | 315 | 175 | 175 | 175 | 24 | A | B13 |
| 18 | BCI 93 | EFB-93 | 12 | 92 | 143 | 900 | 353 | 175 | 175 | 175 | 24 | A | B13 |
Note:
1. In the Dimension columns: L = Length, W = Width, H = Height, TH = Total Height.
2. CCA (Cold Cranking Amps) rating is for reference only. CCA is a theoretically calculated average value. Actual performance may vary due to test conditions and standards.
3. Due to the wide range of battery models, if the battery model you are interested in is not shown in the specification chart, please contact us.
4. The specifications are subject to update without notification for reasons of improvement.
5. For further detailed information, please visit our vertical automotive battery site: www.auto-battery.com
Terminal Type
Cell Layout for BCI Standard
Base Hold Down
What does BCI group size mean?
BCI (Battery Council International) group numbers, such as Group 24, 27 or 31, define the case dimensions, terminal type and hold-down configuration, making it easy to match a battery to the vehicle battery tray.
What do the polarity codes 10, 11, 18 and 24 mean in the BCI table?
These are BCI-standard codes for terminal positions. Models with an R suffix, such as 51R and 27R, use the reversed polarity of the base group. The Tech Drawing section illustrates the layouts for each configuration.
What is the difference between the TOP, STUD and DUAL terminals on the EFB-31?
The EFB-31 is offered with three terminal options: TOP posts, STUD threaded terminals and DUAL combination terminals, covering different truck, bus and heavy equipment connection requirements.
Which BCI groups are common in start-stop vehicles?
Groups 47, 48 and 49 are widely used in European start-stop passenger cars, while Groups 51, 24, 27, 35 and 90 to 93 cover North American and Asian vehicle applications.
RELATED BATTERY RANGES
AGM Automotive BatteriesAGM start-stop automotive battery seriesSMF Automotive BatteriesSMF maintenance-free auto battery seriesDry Charged Auto BatteriesDry charged auto battery series
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