1AU - Universal Battery Charger & Rejuvenator

[Yaro1776]

1AU Bonus,

I have used the 1AU to successfully recharge many batteries and have found the NiCads to be obstinate at times in comparison to the NiMH's and LAB's. The NiCad batteries have some issues with charge memory and I have observed this a number of times. DeWalt cordless tools are popular due to price point, however they have battery issues that I have noted in several instances where the battery can only be charged to a certain voltage. Recently, I recharged two of these 12 volt units with 1 AU and was able to obtain a 9.5 volt and 11.5 volt recharge from an otherwise useless battery. Both batteries were subsequently cycled several times with no improvement in final voltage. My thought was that they were toast!

I was going to a trade show and tossed these batteries into the trunk of my vehicle where they experienced below 0 F temperatures overnight. For show and tell purposes I then used these batteries at the trade show with the 1AU. To my amazement both of the batteries took a charge to the expected voltage - stunned I watched the voltmeter climb to 13.5+ volts and both batteries finally were charged to 12 volts ( 12.35 v). I returned both of these batteries to the original party - have not heard back from them yet as to performance - I will follow up!

Check out w/Google Battery University - excellent info on all types of batteries. The NiCad and Lithium Ion sections are tres informative.

Yaro

[Aaron Murakami]

I think this battery is coming back to life!

Glad to hear it!

The 1amp draw on a 1.3 ah battery is a really big discharge rate for cycling. I know using them on a tool will draw quite a bit, but with the CBA, I'd enter a c20 or c10 rate at the most. You can draw on them harder for the first few, but after that, I'd really reduce the draw down current.

So 1.3ah battery, instead of an amp, I'd only draw 65ma (c20) or 130ma (c10). It will take a lot longer, but you will really see what the battery capacity is compared to the manufacturers spec.

What voltage are you taking the batteries down to?

[Gary Hammond]

Hi Aaron,

Thanks for the response. I'll switch to a c10 or c20 rate next time. I always use c20 for lead acid batteries, but just used the default value of the CBA III for the NiCads. I don't have any experience with NiCads so was a little unsure of the proper rate. I also don't know how much the drill pulls out of them in normal use.

What voltage are you taking the batteries down to?

Again, I just used the default value of the CBA III which is .9 volts/cell for NiCads. So that was 9 volts for the 10 cell/12.0 volt battery. And the default current draw for the CBA III is c1 or 1.3 amps for a 1.3 amp hr rated battery. I thought that was a bit too much for the condition the batteries were in, so I backed it off to 1.0 amp discharge.

[Aaron Murakami]

Hi Aaron,

Thanks for the response. I'll switch to a c10 or c20 rate next time. I always use c20 for lead acid batteries, but just used the default value of the CBA III for the NiCads. I don't have any experience with NiCads so was a little unsure of the proper rate. I also don't know how much the drill pulls out of them in normal use.



Again, I just used the default value of the CBA III which is .9 volts/cell for NiCads. So that was 9 volts for the 10 cell/12.0 volt battery. And the default current draw for the CBA III is c1 or 1.3 amps for a 1.3 amp hr rated battery. I thought that was a bit too much for the condition the batteries were in, so I backed it off to 1.0 amp discharge.

It will be interesting to see what you can get out of the battery with a lower draw like c10 or c20. Most of my tool batts are 18v. I can do some CBA IV tests on them, but I have it tied up on the Walmart garden batts right now.

[gabiX87]

Hi, I already have the 1AU and using it everyday. Everything is working fine. I had to put the charger into the basement because of quiet loud buzz/noise/rattle while charging. It's kinda hard to be with it in one room while in operation. Is it normal? How about your charger ?

Thank you

[Aaron Murakami]

Hi, I already have the 1AU and using it everyday. Everything is working fine. I had to put the charger into the basement because of quiet loud buzz/noise/rattle while charging. It's kinda hard to be with it in one room while in operation. Is it normal? How about your charger ?

Thank you

The bigger the battery and/or the higher the setting, the more noise.

As long as your batteries are within the rating for each particular setting, you're charger is fine.

[gabiX87]

Another question.

Can I charge two 12V power tool (or LABs) batteries in series as 24V on the 7 or 8 setting on the 1AU ?

EDIT: With identical Ah rating and chemistry , of course.