We've got a musical hanging mobile for Charlie's crib, and the instructions state "do not use rechargeable batteries". Apparently, it's a safety thing. Anyone know what they're talking about?

Maybe more likely to leak or catch fire compared to alkalines and they just want to keep themselves covered? Unlikely that would happen but its all I can think of.

Could it be that rechargeable batteries only put out 1.2V rather then 1.5V? Might make the music slooower.

Duracell or Energizer or [insert popular brand here] are the parent of or aligned with that ma manufacturer or distributor?

Not a safety reason though.

Maybe the device has no shutoff and will drain rechargeable batteries down past viability.

Only if they're NiCads. Rechargeable alkalines are the normal 1.5--1.6 volts, as are the Lithium-Ion and NiMH batteries.

Somewhere on this bbs, probably more than 5 years ago, someone posted a wonderful tutorial about battery technology. Anybody know where it is?

tanstaafl.

http://empegbbs.com/ubbthreads.php?ubb=showflat&Number=183668

Searched for "+battery +rechargeable" older then 3 years with the preview on.

NiMH, which are the most common rechargeable batteries IME, are 1.2V as well.

It probably has to do with the current draw of the motor. It may overheat rechargeables while alkalines won't.

I asked a friend of mine this question once, and he claimed that NIMH had lower output resistance than alkalines. If a short were to occur more current could be output from NIMH, possibly causing a fire.

I can't think of any safety reasons that you wouldn't be able to use a rechargeable over a regular alkaline/whatever cell.

Most rechargeable batteries do have a lower internal resistance but if your product is shorting out anyway then you've got other issues.

The lower cell voltage shouldn't affect much either since the voltage of an alkaline battery will slow drop as well.

You get warnings about putting non-rechargable batteries into devices that are expecting rechargeable batteries but this isn't the case here.

Wow- that is a great thread!

I'm recently involving myself with some rather in-depth maintenance of NiMH batteries (primarily for my growing fleet of roombas, but also other cordless devices) and have been doing a lot of reading.
Some good sources:
Batteries In A Portable World
http://www.buchmann.ca/
and
Battery University
http://www.batteryuniversity.com/

Meanwhile, I'm seriously considering purchasing this Computerized Battery Analyzer.

Anyone into battery service that would care to comment?

That analyzer, while cheap, PC-based, and cool, is discharge only. That leaves me with having to charge my batteries somehow.

Further research has brought me to this series of charger/analyzers:
http://www.bantam301.20m.com/

I'm thinking seriously about the BC6 because:
1. it plugs into the wall
2. cheapest of 3 options
3. suits needs

The needs are to examine/rebuild/maintain battery packs for my Roombas (14.4V NiMH) and DeWalt tools (18V NiMH or NiCd).
I was thinking of doing intensive examinations 6 cells per trial in order to find the lagging cells in the batteries. Then attempt to revive the weaklings or, worst case, replace them.

(I realize this is quite a jump from the original topic on this thread, sorry)

Well, unless you disassemble/reassemble the actual battery packs (to access the individual cells), I don't see how this product can help with that.

The DeWalt chargers are rather famous for being very very good at what they do, which is charging (fast/slow/trickle) and maintaining pretty much any NiCD battery packs.

The best real improvement over the one that comes with the tool(s), is their fancier $100 15-minute quick charger. I have the older "Super Charger" model, and have no complaints.

Cheers

Hi Mark!
Yes- it is my full intention to open the battery cases. I think that my growing mountain of 'useless' packs are only on the pile due to one or two cells in each battery.
The search for battery/cell "reworking" (as opposed to simple recharging) started over at the Roomba board.
I was wondering if anyone in the illustrious empeg BBS community had any experiences or tips to offer.

I agree that the DeWalt charger does a great job of maintaining the battery packs, but in this case I'm going beyond maintenance into the realm of repair.

You can find a clone of it, except that it needs am external power supply on DealExtreme for US$ 50 shipped. I don't know if the quality is the same, though.

Stig

Ah, a worthy effort, then!

I generally would be less environmentally friendly, and simply replace all of the internal cells with new ones, but your approach is slightly more cost effective, and possibly much better for the planet.

Cheers

Holy Crap!
The prices on that site are unbelievable!

Thanks!

I know. I've spent quite a lot of money on that site the last two months. And it's all Mark's fault! Talking about it all the time...

Stig

For some odd reason the dealextreme site isn't opening for me tonight.

I did a bit more googling on the 'Mystery' charger and (among other things) found this informative thread at an RC board:
are they identical?

...interesting.

The Bantam stands alone as a dual-power unit and seems to have the highest (or most consistent) quality in design, build, and calibration.
Hmmmm... I need to decide if $100 more is worth it for NiMHs and NiCds.

Working fine here right now.

Yes- it's working for me, too.

Further research reveals loads of these chargers in the $50-100 range:
hobby site linkie

I've got a bit more reading to do before I make up my mind... good grief!

Yeah it was definitely broken this morning but it's back now.

I'm pretty certain I started buying stuff from there based on one of Mark's posts

I'm going to buy this one-
MAX E6 Digital Lipo Charger
It's not as cheap as the one from DealExtreme, but they only deal with PayPal and I don't like to share my bank account info with folks on the internet, so PayPal is out for me.

I also like how the Max E6 comes with a bunch of wires, temp sensor, and software.
I found a 12V 2.5A power supply in the garage that will get me started.

Another option and one that looks very enticing is this
Mega Power Infinity-960SR w/ Balancer 12S
Also a copy of a high-end charger, but able to balance 12 cells! Perfect for the roomba batteries, but $200 and I'd probably have to get an upgraded power supply.
If things go well enough with the Max E6 and I feel the need down the line for the fancy-shmancy stuff then I'll spend more money for the better equipment.

One thing that has me confused is that each of these 'cell balancing' chargers only talk about being able to balance Lithium-style batteries. They don't say that they can *only* balance lithium batteries, they *only* say that they can balance lithium batteries. Subtle.
It's my impression that lithiums are very sensitive to being unbalanced during charge or discharge and other chemistries not so much (certainly without the danger).
So- I'm assuming that the ability to balance lithium cells should extend to being able to balance other cells, too, but the documentation doesn't say this explicitly.

I'll keep you guys posted how this system works out with my battery projects.

You should just be able to pay with a credit card through PayPal.

I did that for a while when PayPal first started up, but there was a limit on how long you could continue to do the credit card thing without 'certifying' (or somesuch similar concept) your PayPal account by providing them with bank info.
I used PayPal up to that limit and then stopped.

Perhaps they've changed their ways. I'll have to go see.

edit:
Ok- they've changed the limits. Before it was only a few hundred dollars that you could send before they required 'verification'. Now it is $10k. The Personal (unverified) Account also has receiving and withdrawal limits of $500/mo.
Hmm...
I'm still happy with the charger I selected, but now I have lost my reason *not* to shop at DealExertion.com.

You don't even need an account. PayPal accepts credit cards from people who have no PayPal account.

On DealExtreme, you have to use the "Standard PayPal Checkout" and then PayPal's "Guest Checkout". It's not even as hard as that makes it seem, which is not very.

Thanks, Bitt!