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_-_Airshield_Battery_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.

[Ryan Baker]

My Trend pro batteries are still going pretty strong (they are starting to lose capacity just a bit at this point). I have always intended to rebuild them just as you did when they get bad enough. Thanks for posting your source.

[Ted Evans]

Really appreciate the info Ken, battery packs are a pet peeve of mine.

[Ken Glass]

Hey All,
I am sure you are bored to death with my posts by now, but I did wanted to give you a final update. The second Battery pack I rebuilt and charged for 12 hours was turned on at 7:15 am yesterday morning and when I shut it off last evening at 7:15 pm, it was still going strong and wasn't even beeping as of yet. That's 12 hours run time. All in all the rebuild seems to be a success and a very inexpensive alternative to buying a new pack.

[kurt sligh]

Hmmm, has anyone been able to create an entire battery pack? I'd like a second battery pack but don't want to buy their's if I can make one from scratch. I just got mine yesterday so I haven't really looked at how the battery pack was constructed.

[dan roscigno]

I know this is an old thread, and I apologize for reviving it :)

Does anyone have a source for the 70 degree c thermal fuse in the battery pack for the Airshield Pro?

Thanks,
Dan

[Jeffrey J Smith]

Dan: Try Goodman's in Florida or even Radio Shack - they're pretty commonly available at electronics parts outlets. Google is our friend.
Funny you should resurrect this old thread - last weekend I finally rebuilt one of my battery packs from the info that was posted here. I had bought all the parts for two battery packs almost a year ago and put off rebuilding until the batteries were obviously shot.
The rebuild went very smoothly, just mimicking what was done in the original with the new batteries. I reused the old fuse. The new/rebuilt pack seems to work great so far.

[Darryl Hansen]

Ditto on the Trend Customer Service. I would also like to see a tutorial. I believe the one mentioned in another post is for the older style Trend rather than the Pro. One of my packs does give the low voltage warning soon after turning it on but the fan will run for several hours before slowing down.

[Mark Levitski]

I too reused the old fuses when I rebuilt my two Trend batteries last year. I have had great results since then. Way better so far than the original batteries. Thanks Ken.

[Ken Glass]

Hey All,
I am glad everyone is having the same success I enjoyed when I posted this. I turned for 9 hours yesterday and my re-built packs worked well.....I also used the existing fuse for my re-build

[Ray Bell]

Ok, sorry, but I am confused (which isn't unusual) but Ken, is this for the original Trend, or the Airshield Pro? Thank you for posting this.

[Ken Glass]

Ray,
The re-build is for the Trend Pro not the original There are suggested re-builds for the original Trend Air shield in the archives. do a search and you will find them....

[Jim Underwood]

Ever post the tutorial?

[Ken Glass]

Jim,
I haven't because there seems to be a liability issue if I post a pictorial how to, even with this simple re-build. There will alway be someone who wants to sue you for something, just waiting around the bend. It is very straightforward. If you follow the existing wiring and solder all connections the same as the spent batteries are wired, there should be no problems. Remember, to use the same polarity as the existing batteries. The case is easy to open with a screw driver on the tabs and if in doubt, before you start, take a picture or two to be sure. Always be safe and remember I can't endorse this procedure...........but it works the same as the original.

[dan roscigno]

Thanks for the info on the thermal fuse folks (and for the original post, Ken). I will reuse the existing. I am also ordering some, Jeffrey was right, Radio Shack has replacements. The part number is NTE8070. If anyone needs one and does not have a Radio Shack nearby, there is a Radio Shack store that sells through Ebay, with shipping these are under $2.

Regarding polarity, the replacement batteries may not be marked. Look at the tabs, the positive terminal may be covered with a black cover. Also, on both the original batteries and the Tenergy replacement, the positive end of the battery has a white ring like so:
265874

The negative terminal has no white ring:
265875
Using rosin core solder and soldering paste makes things go quickly and helps get a good connection:
265876

Finally, I bought a Smart Charger:
265877

You may want to buy this first; I have read posts form three people saying that they had "dead" Trend battery packs, bought either this charger or a similar one, used this instead of the charger from Trend, and are happily using the Trend battery pack with no problems.

[Ray Bell]

Ken, thank for the reply. My Airshield is the Pro model, so this works well. I will print this out and use it when I get the second battery pack.

[Ron Rutter]

Thanks for the info on the thermal fuse folks (and for the original post, Ken). I will reuse the existing. I am also ordering some, Jeffrey was right, Radio Shack has replacements. The part number is NTE8070. If anyone needs one and does not have a Radio Shack nearby, there is a Radio Shack store that sells through Ebay, with shipping these are under $2.

Regarding polarity, the replacement batteries may not be marked. Look at the tabs, the positive terminal may be covered with a black cover. Also, on both the original batteries and the Tenergy replacement, the positive end of the battery has a white ring like so:
265874

The negative terminal has no white ring:
265875
Using rosin core solder and soldering paste makes things go quickly and helps get a good connection:
265876

Finally, I bought a Smart Charger:
265877

You may want to buy this first; I have read posts form three people saying that they had "dead" Trend battery packs, bought either this charger or a similar one, used this instead of the charger from Trend, and are happily using the Trend battery pack with no problems.

Dan / anyone. Can you buy batteries with the tabs already on as you show?? If so where? Tnx. Ron.

[dan roscigno]

Hi Ron,
Ken posted this one:
http://www.batteryjunction.com/tpeh-t43a3600p.html

Just make sure you choose the option to get the tabs. I ordered mine on eBay as battery junction was back ordered on the ones with the tabs.

[Mark Detrick]

I followed this thread and rebuilt the battery pack on the Airshield Pro, and I purchased a smart charger. If I connect the leads of the smart charger to the lead strips on the battery pack I am able to charge the batteries. However, I tried attaching the plug from the original charger onto the smart charger so that I can charge the battery pack while in the Airshield. For some reason this is not working for me. Has anyone had success using a smart charger to charge the batteries while in the Airshield?

[dan roscigno]

Mine charges fine in the mask, but I did see other people posting with the same problem as you. I am guessing that at some point they changed the circuit and the new circuit does not "see" the correct voltage or something. Somebody posted pictures of a home made cradle for the battery, basically a wood box with a couple of nails that will touch the strips on the battery pack while the battery is in the box.

[John King]

Batteries Plus will rebuild battery packs for a fee. If you are not into do-it-yourself, may want to give them a shot at rebuild. - John

[Jerry Toschlog]

I am glad someone revived this post! I just got a shield with other items in a CL deal. The thing is I do not have the battery pack to start with. Can someone tell me the voltage and MA needed in each pack. Thanks Jerry

[Jerry Toschlog]

wow! I just seen the PDF earlier in this thread ....