Black & Decker battery charger
Recommend this product?
The Black & Decker BC40EWB and BC40EB have the same charging technology but the BC40EB has no engine start feature.
There are two different display panels going by model BC40EWB as sold by Wal-Mart in Austin Texas at the time of this writing. I do not know if one version is a later model. The one I have has a liquid crystal display that scrolls information. It is different than the one pictured in this review. I am reviewing the charger with the liquid crystal display. The unit depicted here has a red LED display and about 7 LED indicator lights. Once again, according to Black & Decker the charging technology is identical.
The 5 buttons on the charger with the liquid crystal display are:
Battery Recond (reconditioner)
The volt meter on the charger is fairly accurate. The greatest error was 0.11 volts which is OK. The charger also monitors the current to the battery. This is an excellent feature. At any time, in charging mode, you can press the voltage button and read the battery voltage.
I completely drained a very good battery. The battery was 2 weeks old and had 800 cranking amps at 32 degrees and 640 cold cranking amps. I connected the battery and pressed “charge”. The unit performs well. It started charging and in a few minutes it stops to evaluate the battery. The battery was good so it returns to full charge mode. Eventually, the current to the battery is reduced and then this happens again. When finished the charger went into idle mode and held the battery at 13.39 volts. This is very good. The perfect voltage for a lead acid battery is 13.2 volts and 13.39 volts will do no harm.
After the battery was completely charged, I placed a load of 2 car headlamps on the battery charger and in a few minutes the charger kicks in and starts charging the battery. It still does an excellent job of regulating with a load on the battery.
The charging logic is good. The charger is consuming 16.8 watts in idle maintenance mode. This is good since I’ve seen other popular chargers consume 85 watts. I would like the charger to go to a one watt monitoring mode but I’ve only seen one charger that will do that and it is a 2 amp charger for motorcycle batteries (Schumacher SEM-1562A). It could be used to maintain a large car battery in storage but not to charge it. I prefer the Black & Decker for larger battery charging technology.
Does the battery reconditioner work? This would be a difficult feature to evaluate. I monitored the voltage on the battery for a short while when in the reconditioning mode. The DC voltage remained the same at 13.8 volts. The charger sent pulses of high frequency to the battery. I suspect this would do no harm but the actual improvement of a battery with sulfated plates would take time to test. I do not have an old battery at this time. They sell reconditioning chemicals on the Internet but the local auto parts stores are not aware of it. Therefore, I might try the Black & Decker reconditioning technique but nothing else other than adding distilled water or acid as needed.
A marine (deep cycle) battery has thicker plates and reconditioning would be more applicable for that type of battery. A car battery has many thin lead plates so it can deliver large amounts of starting current. The sulfation process of a discharged car battery happens quickly. Once the lead plates have hardened they are dead. Removing any sulfation leaves nothing else to work with because the plates are so thin. So if the Black & Decker reconditioning technique does not work I would use the battery for its core value on a new battery.
The testing of alternators is easy with the present evolution of electronics and the BC40EWB accomplishes it OK.
I’ve evaluated several of the major car battery charger brands and the Black & Decker BC40EWB is the best. It’s a keeper. The mechanics at Wal-Mart swear by it. I will not be testing the car starting feature at this time but a mechanic at Wal-Mart said this is the one he used for starting cars.
Black & Decker has a phone number for technical support and they are easy to contact. They also provide free PDF service manuals on their web site. Repair parts are also available.
According to Black and Decker you can charge any size lead acid battery with this charger including gel cell batteries.
The following are notes I gathered during the charge process. It took a little over 4 hours to properly charge a new 800 cranking amp car battery. Keep I mind the charger charges at 40 amps in the beginning and then tapers off in the end so it should quickly prepare a battery to start a car. The taper charge in the end is for a more thorough charge.
7.0 floating voltage
Starts charging with 6.2 amps at 115vac line input
Indicates charging of 40.4 amps charge rate to battery.
Does sampling test and then resumes 40 amp charge rate.
14 amps charge rate. Start time not known. 14.59 volts
Charge amperage is gradually decreasing. It is more of a voltage control process than current control.
5.6 amp charge rate, 14.62 volts
0.85 amps at 115 volt supply
2.2 amps charge rate, 14.22 volts, and went to idle mode. Fan to very low speed. 0.14 amps at line input or 16.8 watts. “Battery Fully Charged” indicated.
Battery Charged and holding at 13.39 volts according to high accuracy volt meter. Charger indicates 13.5 volts.
End of test.
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