NiMH vs. NiCAD question

[tcsenter]

I was looking to purchase a new 'proprietary' battery for my Panasonic 900MHz cordless and find out its nothing more than 3 conventional NiCAD "AA" batteries bundled in a plastic case with two electrodes along the side. Specs are:

[*]Panasonic Type 92
[*]3.6V
[*]600mAH
[*].6A
[*]2W

So I begin to think, instead of spending $20 on a new battery pack, can I just rebuild the current one with NiMH 1.2V "AA"?

DOH! I just found the answer to my own question...

"AA" format fits most electronic devices and are a direct replacement for Alkaline and NiCD batteries

"AA" 1700mAh Rechargeable NiMH Battery Cell with Solder Tabs. Now there is absolutely no reason to use NiCD batteries any more. The MAHA 1700 mAH NiMH batteries practically make them obsolete. You can use these new "AA" size NiMH batteries in all your Equipment that requires Battery Packs, such as Cordless Phones, or which use individual batteries such as Electric Shavers, etc....

These cells are designed for the Do-It-Yourselfer who knows how to make their own battery packs, or how to replace them in equipment that requires soldered in batteries. They do need to be soldered into packs before they can be used in most cases. Unless you have basis soldering skills, and battery pack knowledge, Do Not Purchase these Batteries. The very best choice for replacement of NiCD type rechargeable batteries for remote control operations applications. Their Super performance and light weight make them excellent for use in remote control planes, boats, cars, etc...

Woot!

 

[ApacheXMD]

um. except that the charging circuit for nimh is different from nicd. For a phone that's gonna be left on the base for extended periods of time, you might overcharge the nimh cells, blow them up, start a fire, sterilize yourself, or some other bad things might happen. Anyway it's generally not a good idea to charge nimh with a nicd charger. Nicd Cells are cheap too. Use those if you insist on making your own pack.

Not to mention that most battery packs use shorter length cells than consumer AAs. Make sure the cells you pick will fit in the phone

And to solder battery packs, you're gonna need a nice strong soldering iron, 100watts at least. You want to be able heat up the ends of the cell without heating up the whole cell which can damage them. So you need a HOT iron. And to connect those cells in series, get yourself some desoldering wick from Radio Shack. Those work well for making packs. RC hobby shops will sell you some shrink wrap to make it look nice. But electrical tape works just as well

-patchy

 

[tcsenter]

Well the folks at Thomas Distributing say these are direct replacements for NiCD in rechargeable environments. Charging should never be an issue.

600mAH vs. 1700mAH

If my phone's built-in charger can 'overcharge' a battery capable of more than twice the energy capacity as the battery its intended to charge, something is wrong. If anything, these batteries will be constantly undercharged.

 

[DonCrescas]

If this is possible, I would love to use this on my norelco shaver which has two crappy NiCd AA's soldered into it. But I believe tou are corerect about needing more than a basic 30W iron which might overheat the batteries and/or the charging circuit.

 

[WobbleWobble]

I've charged NiNH in an old NiCAD charger before no problem

 

[tcsenter]

I've done some amazing things with a 10 year-old generic Radio Shack 45W soldering iron that mere mortals couldn't contemplate with an expensive 100W model.

T-E-C-H-N-I-Q-U-E

 

[Thegonagle]

A cordless phone's slow charger will not overcharge the NiMH cells. The charger will need two to three times longer to fully charge the 1700 mAH cells vs. the 600 mAH NiCd cells, but that will be your biggest repercussion.

I say, if you can successfully fit new cells to the old pack, go for it!

 

[Ornery]

Went down this road recently. Current battery pack goes 3 weeks between charges. My battery pack.

 

[tcsenter]

Originally posted by: Ornery
Went down this road recently. Current battery pack goes 3 weeks between charges. My battery pack.

Awesome! I have a Panasonic KX-TC900D-W that I am very satisfied with after wasting money on General Electric and Southwest Bell garbage for several years.

I might trade-up to 2000mAH cells instead of 1700mAH. I planned to charge them fully in a dedicated charger before-hand. My phone base has a spare battery charger, too.

The trick with soldering batteries is to scuff-up the soldering tabs or contacts with some emery cloth, clean the contact with isopropyl alcohol, tin the iron liberally and press the tip to the joint for no more than three full seconds and roll-off. At least that's what I've done and it seems to produce a strong enough joint to withstand any reasonable use.

Also, don't 'twist' the copper wires into one, straighten the wires out and flatten them.

 

[0roo0roo]

nicds aren't useless.. for ultra high drain like rc cars, they are still better.

 

[Ornery]

The story I heard, on charging NiMH VS NiCAD, is that the NiMHs have to be topped off with a 'pulse' type charge. I'm stuck with the chargers that come with the phones, so I'll take what I can get out of them. Only a dollar a piece for each battery, so who cares?

Tight quarters in my battery compartments, so I had to solder strategically for fit.

I LOVE my 2 older model Panasonics (KX-TC1750B), but the 2 newer ones I got for my sons, (KX-TC1703B) aren't as nice. Batteries don't last as long, caller ID feature doesn't function as well, and the sound isn't as good on either end. I'll shop VERY carefully for any replacements for these phones.

 

[McCarthy]

I took a similar battery pack out of my GE phone. Got to looking, the 2/3 length "AA" nicad pack and AAA batteries looked close, trial fit one, AAA happened to fit the battery compartment perfectly. Two pieces of tinfoil later I now have a phone that can stay off the charger for three weeks at a time instead of a few days and gives me six or more hours of talk time instead of the one hour I got with fresh packs from Radio Shack. Been like this for most of a year now, no problems.

 

[tcsenter]

I'm wondering about my sister's older (and completely dead) NiMH laptop battery (Duracell DR202/DR36S type). I wonder if there aren't like a bunch of conventional "C" type battery cells in there or something. Only one way to find out!

 

[Ornery]

Yikes, that Lithium Ion is a whole different animal... and expensive!

 

[dman]

I built a homemade NiMH pack for my old vtech phone and charged it in the spare charger in the base (that also let the phone work if the power went out--nice feature, few phones have these days). That phone started acting up (just got old, clicking/static/etc) so I ended up replacing it. New phone I made sure had NiMH cells in the package.

If more people bought models only with NiMH cells they'd stop producing models with crappy NiCD packs that die and cost $15-20 to replace. but that would probably hurt their sales/profit margins so it really will require consumer demand. Get the word out.

 

[tcsenter]

Originally posted by: Ornery
Yikes, that Lithium Ion is a whole different animal... and expensive!

There are two versions of the DR202/DR36 Type package:

12V NiMH

10.8V Li-Ion

They are pretty much interchangable and share the exact same battery enclosure. My sister has the 12V NiMH.