dcsimg

Bosch 12V 4.0 amp hour Battery Review (BAT420)

This topic contains 46 replies, has 20 voices, and was last updated by Profile photo of Dirty DirtyWhiteBoy 1 year, 10 months ago.

Viewing 20 posts - 1 through 20 (of 47 total)
  • Author
    Posts
  • #72499
    Profile photo of Dan
    woodman_412
    Moderator

    I recently received one of the new 12V, 4.0 amp hour batteries (BAT420) from Bosch to test and review. My Bosch 12V tools are what I reach for most in my shop and on site when it comes to drills, drivers and my oscillating multi-tools. Since I use my 12V tools so frequently in my work, I was excited to test the performance of the new BAT420 firsthand.

    When I received the BAT420, it came packaged in the typical clear plastic packaging that most batteries are sold in. After opening the package, I fully charged the battery since it was sent with about one third charge capacity. To test the performance of the new 4.0 amp hour battery and compare it to the existing 1.3 amp hour batteries (BAT412) that I currently use, I set up two tests. The first test involved using my Bosch oscillating multi-tool and the second test involved using my Bosch impact driver. I was expecting to see test results that reflected Bosch’s claim of nearly 3 times the run time for the BAT420 compared to the BAT412, but in my tests it far exceeded that.

    To set up my first test, I used my Bosch PS50 oscillating multi-tool with 120 grit sandpaper installed on the triangle pad. The test was done sanding maple with the variable speed set at full speed and the tool was run until the battery ran out completely. There have been complaints in various reviews of the PS50 that the runtime is relatively short and I have found that to be the case as well, so I was very curious to see what the new BAT420 would do to remedy that. When I ran the sanding test on the BAT412, I recorded a time of 12 minutes 17 seconds. When I ran the same test on the BAT420, I recorded a time of 54 minutes 17 seconds. I was quite surprised and impressed that the new BAT420 gave a runtime of 4.5 times that of the BAT412! It is definitely a game changer when it comes to the run time of the Bosch PS50 oscillating multi-tool. Tasks that were not really practical to use the PS50 for previously due to run time are now easily achievable. This new BAT420 really changes the way I look at my PS50 oscillating multi-tool and the tasks that I will use it for.

    To set up my second test, I used my Bosch PS41 impact driver and drove #8 screws that were 3” long into 3” thick spruce lumber. Rather than being gauged by runtime, this test would be gauged by the number of screws driven before the battery ran out. When I ran the test on the BAT412, I was able to drive 40.5 screws before the battery ran out. When I ran the same test on the BAT420, I was able to drive 195.5 screws before the battery ran out. So in this test the BAT420 had 4.8 times the runtime over the BAT412, which was very impressive! Although it is hard to quantify, it felt like there was slightly more torque available when using the BAT420 compared to the BAT412. In both of these tests the BAT420 was cool to the touch after being fully discharged so it obviously runs very efficiently. The battery also has a heat dissipation grid on the bottom similar to the Bosch 18V batteries.

    My third test was simply the time that each battery took to fully charge from being completely empty. The BAT412 took 33 minutes to achieve a full charge and the BAT420 took 1 hour 26 minutes to achieve a full charge. So the extra runtime performance of the BAT420 comes at the cost of extra time to charge, but it only takes 2.6 times longer to charge. When you compare the extra charge time factor of 2.6 to the extra runtime factor of 4.5 – 4.8, I would say that is a great trade off. Based on my test numbers the BAT420 will give you more working time and less time charging which means more productivity.

    The BAT420 is obviously larger and heavier than the BAT412 but I didn’t find this to be an issue at all during use. The BAT412 weighs approx. 181 grams and the BAT420 weighs approx. 318 grams. The extra size is actually an advantage when it comes to the ability to stand the tool up as you can see in the photos. There are times when it is easier to stand the tool up rather than lay it down and the BAT420 works very well for that. I found that it does change the balance of the tool slightly but not in a negative way. It actually improved the balance of the drills and drivers and the oscillating multi-tool just required holding the tool differently. I could see the extra size of the BAT420 being an issue in very tight spaces but for the majority of tasks it is not an issue. As you can see in the photos, the oscillating multi-tool can be held parallel to the work surface without the battery touching the surface.

    In conclusion, the new BAT420 has excellent performance and I would highly recommend it as an upgrade to anyone with the Bosch 12V system. I will be getting a lot of use out of the new BAT420 and it will be my go-to battery for all of my demanding 12V tool applications. I would like to thank Bosch for the opportunity to test the new BAT420. It certainly met and exceeded my expectations for performance and runtime.

    Dan

    danpattison.com

    #72505
    Profile photo of Matt
    mattryyc
    Pro
    Calgary, Alberta

    Great review, thanks Dan. It seems like the 4.0 batteries really remedy the most common complaint of the OMT. I would love to see Bosch packaging these batteries with more of the 12v tools – especially the OMT. I have a number of Milwaukee 12v, part of my decision was a lack of fat pack batteries and low runtime complaints, I think Bosch are really stepping it up now with these batteries available.

    #72506
    Profile photo of Jason
    MKE_Voltage
    Moderator
    Saint Francis, WI

    Holy smokes Dan, that is a heck of a review! I love how long that battery allows the OMT to run. If I would have read your review before I purchased the Milwaukee OMT I would have 100% gone for the BTP 12V OMT with the upgraded battery.

    Thanks for doing all of this work for our benefit.

    #72508

    Nice review Dan. I’ve been curious if the 4.0 was worth the cost of admission and it looks like it is. I also suspected that there should be a slight power bump due to the higher ah rating.

    #72509
    Profile photo of Hong Woon
    rylim
    Pro
    Missouri City, Texas

    Hi, Dan.

    After I read through your review, I am really impressed with the run time of this battery in the monster ( Oscillating tool ).

    I curious about run time of this fresh new cycle battery compared to the plenty cycle of the 1.3 Ah. In my opinion, I think the run time of this battery will slightly drop after few cycle

    #72512
    Profile photo of Dan
    woodman_412
    Moderator

    Hong, the 1.3 Ah battery (BAT412) that I used in my tests is a fairly new battery that has only been cycled 5 or 6 times so it should still be an accurate reflection of the performance of each. You are right though that the run time may decline over time but based on my experience with my older 12V Bosch batteries I don’t think it will be very noticeable.

    Dan

    danpattison.com

    #72536
    Profile photo of Boyd
    Dabbs
    Moderator

    Super review as always Dan, That 4.0 is very impressive over the 1.3. And I don’t see any hinderance in the bigger size. Thanks for the review and pics

    #72544
    Profile photo of Hong Woon
    rylim
    Pro
    Missouri City, Texas

    Dan. Thanks You for your reply.

    I guess you must have a lot of 12V battery

    #72551
    Profile photo of Jeff
    jkirk
    Moderator
    halifax, nova scotia

    wow, i didnt think the run time would be so different, i thought it was supposed to be like 2x the 1.3 amp batteries.. i have yet to test my milwaukee 4 amp batteries actual run time compared to teh smaller ones

    #72554
    Profile photo of Chad
    ChadM
    Moderator
    East Palestine, Ohio

    Great review, Dan! How did your hand feel after the 54 minute 17 second sand-fest?

    I purchased my first 12 volt set recently(Milwaukee) and was really surprised by the amount of power that the system had…I was expecting a light duty tool and that was far from the case.

    Chad

    A Working Pro since 1993

    Member since 12/07/2013

    A Carpenter's Journal

    #72558
    Profile photo of Matthew
    MRenes
    Pro
    Vienna, Missouri

    Great review Dan. That is a heck of a lot more using time with the bigger battery.

    #72568
    Profile photo of Dan
    woodman_412
    Moderator

    Thanks guys.

    Great review, Dan! How did your hand feel after the 54 minute 17 second sand-fest?

    Chad, my hand actually felt fine after doing all the sanding. My neck was a little sore from looking down that long but my hand was fine. My trigger finger was a little sore though after driving all those screws for the impact driver test.

    Dan

    danpattison.com

    #72569

    Great review, Dan. Very impressive results. That is an amazing jump in performance.

    Orange County, CA

    #72575
    Profile photo of Sven
    svensshutters
    Pro
    Colorado Springs, CO

    Very nice review Dan. I am as impressed as everyone else here. What a huge difference.

    #73019
    Profile photo of Dirty
    DirtyWhiteBoy
    Pro
    Honolulu,, Hi.

    Great review Dan, Looks like I’ll need to up grade to the 4Ah batteries.

    Dirty

    A Working Pro since 1988!

    Member since January 26, 2013.

    #73158
    Profile photo of Dan
    woodman_412
    Moderator

    How many of you guys use Bosch 12V tools?

    Dan

    danpattison.com

    #73175

    How many of you guys use Bosch 12V tools?

    Guilty as charged.

    #73178
    Profile photo of Chad
    ChadM
    Moderator
    East Palestine, Ohio

    How many of you guys use Bosch 12V tools?

    None for me yet….

    Chad

    A Working Pro since 1993

    Member since 12/07/2013

    A Carpenter's Journal

    #73192
    Profile photo of Sven
    svensshutters
    Pro
    Colorado Springs, CO

    How many of you guys use Bosch 12V tools?

    Not yet, but soon. I need to create a 12V box for inside work.

    #73197
    Profile photo of Matt
    mattryyc
    Pro
    Calgary, Alberta

    How many of you guys use Bosch 12V tools?

    I don’t have any yet – that might change though. I have a few Milwaukee M12 and have really grown to like using the small form factor over the larger tool.

Viewing 20 posts - 1 through 20 (of 47 total)

You must login or register for the Pro Forum to reply to this topic.

queries. 0.999 seconds