Alternative: A rebuild for Trend Air Pro Battery Pack

[Ken Glass]

Hey All,
First I want to say I am a big fan of Trend's products and have the Air Pro Shield, and use it daily. Customer service at Trend is the best and has always given me more than I asked for. I have found though, that the replacement battery packs to be very expensive from $65-$80 at most places, and my last two Battery Packs didn't last much over a year. I decided to find an alternative to the price and found batteries with the same voltage and have approx the same rating for ah. The case of the 8 hours pack opens easily with tabs and after cutting away the hot glue on the battery pack I was able to see the wiring configuration. I duplicated that with a few soldering connections on the new Batteries found here. http://www.batteryjunction.com/tpeh-t43a3600p.html I used the existing leads and bought the new batteries with soldering tabs on them. It made it much easier to solder to the new batteries. It took about 30 minutes to replace batteries in two battery packs. I used flux on the tabs which made soldering a breeze. I just finished them yesterday and charged them for 12 hours so far. The new batteries fit perfectly in the existing pack, so there is need to change anything other than the batteries. Note: The replacement battery is not AA. It is a 4/3A and bigger than AA, so keep that in mind when searching for replacement batteries. This morning I tried both re-built packs in my Trend Air Pro and found that they seem to work very well. The true test will be after a long day of turning. I will post a tutorial later, if there is any interest. I bought 6 batteries with tabs and paid a total of $27 with shipping. That is enough to do two battery packs, which would have cost an average of $145. Disclaimer: This procedure is not approved by anyone and I don't assume any responsibility for those wishing to duplicate it. It was a personal test to find an alternative and so I don't endorse the process or even recommend it to anyone.

[Joe McMahon]

I would be interested in the tutorial. I do have another one here http://azwoodturners.org/100_-_Airsh...ttery_Pack.pdf

[Jim Burr]

Joe, I think the one you posted is only for the Airshield, not the Airshield Pro; they have different power requirements.

[John Coloccia]

I will give one warning here. It is easy to rebuild NiCd/NiMH battery backs. I've built and repaired many many many battery packs over the years. Before you work with, touch or look at NiCD batteries, REMOVE ANY JEWELRY FROM YOUR FINGERS, HANDS AND WRISTS.

NiCd batteries have an absolutely monstrous capacity for supplying large amounts of current in a very short periods of time, and a short across the leads with a piece of jewelry could easily land you in the hospital with some pretty serious burn injuries. When I was building packs, it was pretty common to use a piece or two of desoldering braid to bridge across the bottom of the pack (desoldering braid is heavy gauge, flat, solders easily and is convenient...everything you look for!). I accidentally shorted the pack while installing the connector on the end. I VAPORIZED the desoldering braid, leaving just a little stub soldered to each battery, a bunch of smoke and ash, and what was essentially a sunburn on the hand nearest the pack. That woke me up real quick!

So remove the jewelry, clean the area of stray metal parts, and just be aware that they don't behave anything like alkalines.

[Ken Glass]

The batteries in the Air Pro Shield are Nicol Metal Hydride not Ni-cad. There is a big difference.

[Jim Burr]

Ken, how long are your typical turning sessions...I run mine for 6 hours with no problem...just wondering.

[Jim Underwood]

Are the new batteries any smaller or lighter?

[Roger Hirlinger]

Ken, I'd love to see a quick tutorial. Both sets of batteries for my Airshield Pro have gone "toes up" and I have been delaying buying new ones due to the high price. I can barely get 30 minutes out of them before they start to give the low voltage alarm, and it's a really good day when I can spend less than 30 minutes sanding...

[Ken Glass]

Jim B,
I usually turn for at least 5-7 hours, but sometimes even eight hours. It really depends if I have to get a piece out to a Gallery or show. Typically the summer takes me away from the lathe as my other hobbies kick in.

Jim U,
The new batteries are the exact same size in length and width. They are also 1.2 Volts each which equates to 3.6 Volts for 3 of them in series. They are 3.8 Ah instead of 3.6 which is a good thing.

Roger,
I haven't the time this week to do the tutorial, but it is very easy to do as long as you follow the existing soldering connections you can't go wrong. I am sure there are other places to get the batteries, but the Battery Junction has great service and fast shipping too.

[Allen stagg]

Would also love to see a tutorial, just to be clear on how.

[Mark Levitski]

Ken, you offered and now you're gonna hafta do it (the tutorial) .

I too have two batteries for my Pro that are almost gone. I have very disappointed with their lifetime. They do not have enough hours on them to be doing that, and I take care to remove them from the charger when they are fully charged, and I run them down all the way before putting them back on.

I would like to see at least a rough guide of what you did.

Mark

[Ken Glass]

Hey All,
The test on my Air Pro rebuilt pack is progressing. so far 7 hours and still running fine. I charged the new pack for 12 hours and turned the hood on this morning and just got back and checked it and is running at full speed. I will post results as for how long it will run on 1 (one) charge.

[Roger Hirlinger]

Thanks for the update, Ken. I ordered the batteries yesterday from the source you linked. I'm looking forward to trying to rebuild my battery packs.

[Ken Glass]

Hey All,
Final Analysis: The rebuilt battery pack using the Battery Junction batteries I linked above with a 12 hour charge, lasted 9 hours before starting the beeping noise that we all have come to realize is the warning level for discharge. I didn't leave it on any longer, but my experience leads me to believe I had an hour or maybe an hour and a half left before it was discharged completely. I would recommend this re-build, if I had not already written a disclaimer in my first post.

[Ken Glass]

Hey All,
As a footnote, Trend always recommended removing the battery pack from the charger after 14 hours, which is considered a full charge. I personally put mine on a cheap Xmas timer and set the pins to charge for 14 hours and then shut-off. This way they can't overcharge, which is mostly recommended and by morning it is ready for a full day of turning.