Thread: How to Modify Respirator Helmet to Run off Direct DC

Just note that you can't charge NiMH cells with a NiCad charger (well, you can, but they are not so easy-going as NiCads) as they have different charging likes.

Originally Posted by Interwood

Just noticed some interesting NiMH 8000 mah D cells at Altronics too.
Interwood

They are the nipple type not the solder tag type.
DO NOT solder directly to the battery.

Jaycar have the solder tag type
http://www.jaycar.com.au/productView...T&SUBCATID=583

Originally Posted by Sprog

DO NOT solder directly to the battery.

That can be done quite safely and easily. Have done it many times and never had a problem.

Originally Posted by Vernonv

That can be done quite safely and easily. Have done it many times and never had a problem.

YET!

If that were the case then why would manufacturers produce a battery with solder tags and then the same thing but with nipples. According to your statement only the one type is required.

Obviously you are better informed than the battery manufacturers who state NOT to solder onto the battery nipples as it reduces battery life and could cause an explosion.

Originally Posted by Sprog

YET!

EVER!

If that were the case then why would manufacturers produce a battery with solder tags and then the same thing but with nipples. According to your statement only the one type is required.

Maybe you should ask them, but I'm guessing that it's quicker and easier for battery pack manufacturers to solder onto solder tabs than it is to solder onto nipples. But that doesn't mean it can't be done.

Obviously you are better informed than the battery manufacturers who state NOT to solder onto the battery nipples as it reduces battery life and could cause an explosion.

Well I've never seen such a warning, never had a battery explode (and have made many battery packs over the years) and lots of other people do it without problems.

I speak from experience.

Originally Posted by Vernonv

Well I've never seen such a warning, never had a battery explode (and have made many battery packs over the years) and lots of other people do it without problems.

I speak from experience.

Unsafe practices should not be encouraged in a public forum. You do as you like but do not encourage others to do the same as you.
Just because you have not had a problem YET, then it does not follow that it is perfectly safe to follow your example.

I speak from the manufacturers recommendations.

I've had experience soldering directly to batteries over the years, and the biggest problem I have had is joints that aren't joints because of the plating on the terminals.

Here's the technique:

1) Remove the plating on in the area you want to solder on. Sandpaper, file, dremel or even sandblaster, depending on what you have on hand. Just remove the plating!

2) Know how to solder, and don't use a tweeky little soldering iron designed for soldering 0.5mm pitch traces on a PCB. Use something that can dump a reasonable amount of heat, as the metal can suck heat away. (but put away that iron that you use for soldering guttering!!) 40-80 watts is about right.

3) Solder. If you can successfully solder two bits of wire together without conducted heat reducing their insulation to a runny mass, you should be skilled enough for a battery. If you can solder transistors without overheating them, consider yourself overqualified for a battery.

Please note that the radio control plane and car fraternity have been successfully soldering up their own battery packs for years; before that it was the handheld ham/CB radio community.

Batteries (even Li-ion) aren't going to explode from a few seconds contact with a soldering iron - they heat up more than that in the course of normal charging/heavy discharging cycles.

See also:

http://www.yankee-flyers.com/Articles/NiCadSolder.pdf (PDF file with nice pics)
Digital Camera Battery Pack photo - Paul Kline photos at pbase.com
Dissecting DeWalt 36V Packs (A123 Systems)
Soldering onto NiMH batteries? | Sci.Electronics.Basics | Electronics-Related.com
How can I make saddle pack batteries for my R/C car? I can not seem to get the solder to stick to the batteries. | Answerbag
Soldering wires to battery terminals - TechNFun.com
How to Build Your Own RC Car Battery | eHow.com
http://www.rc-soar.com/articles/batterypack/index.htm

Originally Posted by Sprog

Unsafe practices should not be encouraged in a public forum. You do as you like but do not encourage others to do the same as you.
Just because you have not had a problem YET, then it does not follow that it is perfectly safe to follow your example.

I speak from the manufacturers recommendations.

Don't know whether speaking from experience trumps speaking from the manufacturers recommendations.

Could I suggest that Sprog provides a link to those manufacturers' recommendations?

That way we can all compare experience to recommendations.

The method/tips Master Splinter outlined is exactly the way I do it.

One thing to note is that the battery does not heat up during the operation (if you prepare the surface correctly and solder quickly) - compare that the how hot a battery is just after it's been finished charging.

Coincidentally the last battery pack I did (earlier this year) was for a 6V powered respirator and instead of paying $300 for a proprietary Nicad 4000mAH battery I spent about $30 on a 9000mAH NiMH battery (made up of normal nippled C-cells) and a charger.

Those proclaiming something can't be done should probably stay out of the way of those doing it.

Originally Posted by Sprog

Jaycar have the solder tag type
D Size 9000mAH Rechargeable Battery - Solder Tag - Jaycar Electronics

Thanks Sprog.

I visited Jaycar and have decided to use a second battery pack, rather than repacking the Triton Power module at this stage (Cost being the determining factor for now). Alex's instructions and circuit diagram made conversing with the JayCar Salesperson very easy.

About $46 later for same battery used by Alex, Charger for same and switch.

I plan to use the Respirator with external battery power while I am using the Lathe. (Battery being located between Lathe and Grinder) Switching over to the Triton's failing batteries whenever I need to move away from the Lathe. Another battery under the workbench at the other end of the shed is a possibility for later (another $20).

The experimentation continues. Got to put it all together. Then I will be looking at what can be done with the existing NiCd's (if anything) next.