Thinking about an HP-41CL

[Dieter]

(07-26-2016 05:37 AM)renif Wrote:  Probably an increased internal resistance explains the unexpected low charging current, which now is measured slightly higher at 2.4 mA (DC setting, cleaned plus pole).

That's still an extremely low current. If you insert a set of four completely empty batteries, how long does it take for a full charge?

(07-26-2016 05:37 AM)renif Wrote:  My budget plan grows by a set of rechargeable N cells

It doesn't have to grow that much: I just found an offer of a set that includes everything you need: four 500 mAh NiMH batteries, four N-AA adapters and finally a processor-controlled BC700 type charger with 200 mAh default charging current. Since your name sounds German I assume you will have no problem with akkushop.de. I think this is what we call a "Rundum-Sorglos-Paket" over here. ;-)

(07-26-2016 05:37 AM)renif Wrote:  and perhaps the battery shield.

I happened to get one of these with a used 41CV, but I always wondered what if might be good for. ;-)

Dieter

[smp]

(07-26-2016 12:07 PM)Dieter Wrote:  It doesn't have to grow that much: I just found an offer of a set that includes everything you need: four 500 mAh NiMH batteries, four N-AA adapters and finally a processor-controlled BC700 type charger with 200 mAh default charging current. Since your name sounds German I assume you will have no problem with akkushop.de. I think this is what we call a "Rundum-Sorglos-Paket" over here. ;-)

Wow. Too bad I apparently cannot place an order for this kit from here in the USA. This would be pretty much perfect for me.

Right now, I am trying to negotiate a purchase of a rechargeable battery pack from Scott Reynolds:
http://www.ebay.com/itm/122051596492?_tr...EBIDX%3AIT
He told me he normally sells just the rechargeable battery pack for $95. I am hoping to get a bit of a discount as a returning customer. He's currently determining if he has any battery packs available.

smp

[Dieter]

(07-26-2016 12:50 PM)smp Wrote:  Wow. Too bad I apparently cannot place an order for this kit from here in the USA. This would be pretty much perfect for me.

Hmmm... maybe you can email them and simply ask if they will ship to the US. Or you may have a friend or relative over here? The AC adapter can handle any voltage from 100 to 240 V, so all you'd need is a simple mechanical Euro-US-adapter.

But is this charger really not available outside of Europe? It's perfect for N cells as, unlike most others, it offers an relatively low current of 200 mA, AFAIK that's even the default setting. The original design seems to be by LaCrosse, but it is know under lots of different brands and names. Maybe you or someone else can find another charger with similar specs.

(07-26-2016 12:50 PM)smp Wrote:  Right now, I am trying to negotiate a purchase of a rechargeable battery pack

Do you know what kind of cells are used inside these refurbished battery packs? NiMH or NiCd? What capacity? You even seem to get the original 82120A box and the manual that came with it, so the capacity may be close to the original cells (below 100 mAh) – otherwise the charging times do not match the manual. If the electronics inside the pack have not been modified either, that is. ;-)

Dieter

[smp]

Hello all,

So, if I purchase this:

http://www.ebay.com/itm/361509141471?_tr...EBIDX%3AIT

And four of these:

http://www.ebay.com/itm/321911305438?_tr...EBIDX%3AIT

And I get some sort of N size to AA size adapters, or rig up something as others have done here, will that do the trick for me?

EDIT:

What about this much less expensive charger:

http://www.ebay.com/itm/141437175100?_tr...EBIDX%3AIT

Thanks very much, in advance, for your advice.

smp

[Dave Frederickson]

Hi smp,

These batteries are half the price: https://www.amazon.com/1-2V-500MAH-NIMH-...ref=sr_1_1?

I'm not familiar with the EBL charger, but it looks like it has fewer features. The BC-700 offers 3 charge/discharge currents as NiMH batteries should be charged at 0.5 - 1.0C. The BC-700 also offers Discharge, Test, and Refresh modes.

Personally, I like having better control and the Test and Refresh modes are nice to have.

Dave

[Gene]

Those do not have the top buttons on them. Will they work ok in the HP 41?

And note the $7.99 shipping on those half price batteries. :-)

[rprosperi]

(07-26-2016 11:29 PM)smp Wrote:  What about this much less expensive charger:

http://www.ebay.com/itm/141437175100?_tr...EBIDX%3AIT

I too am not familiar with that charger so can't say with certainty, but the BC-700 has been around for years and is well known with users here and reliable. I'd say it's worth the extra money, since you are looking for a quality, long-term solution that will work with several different battery types. This one is known to work with N/AA/AAA cells, and NiCD, NiMH, Eneloop, etc. types.

[smp]

(07-27-2016 12:03 AM)Dave Frederickson Wrote:  I'm not familiar with the EBL charger, but it looks like it has fewer features. The BC-700 offers 3 charge/discharge currents as NiMH batteries should be charged at 0.5 - 1.0C. The BC-700 also offers Discharge, Test, and Refresh modes.

Hi Dave and Bob,

Here are the details:

Code:

1. Input: 100-240V AC,50-60Hz.
2. Output: 1.2V DC 1200mA, AA 1200mA*1, AA 650mA*2, AA 300mA*3, AA 300mA*4
                                        AAA 650mA*1, AAA 300mA*2, AAA 150mA*4 
3. No Load Power Consumption: 1W MAX
4. Full Load Power Consumption: 5W MAX
5. Discharge: 300mA
6. Battery Charge Rate: >=98%

Compatible with:  AA/AAA NI-MH/NI-CD batteries

Maybe not as many features as the BC700, but is there anything critical missing?

Thanks,
smp

[Dave Frederickson]

(07-27-2016 12:29 AM)smp Wrote:  Maybe not as many features as the BC700, but is there anything critical missing?

Thanks,
smp

I think charge current control is important. As mentioned, NiMH batteries should be charged at 0.5 - 1.0C, so my 500mAH N-Cells get charged at 500 mA and my 800 mAH AAA Eneloops for my 71B get charged at 700 mA.

I don't know how the EBL charger determines battery size, so if you put one N-Cell in, is it going to charge at 1200 mA (> 2.0C !) or what?

Dave

[smp]

Thanks very much, guys, for all your observations and advice. It sounds like the BC-700 remains the best bet.

What about Gene's question about the batteries? Does it matter if they do not have a button on the top (plus side)?

smp

[Dave Frederickson]

In a 41 I don't think the button matters, as the 82120A also has flat contacts. In a clamshell, where two of the cells are stacked, you probably want a button top.

Dave

EDIT: See the one review for the batteries from Amazon, "Works as expected. Brought my HP41CX back to life."

[Dieter]

(07-26-2016 11:29 PM)smp Wrote:  So, if I purchase this:
...
And four of these:
...
And I get some sort of N size to AA size adapters, or rig up something as others have done here, will that do the trick for me?

Yes.

(07-26-2016 11:29 PM)smp Wrote:  What about this much less expensive charger:

The description says "only charge batteries of the same size, capacity and technology at the same time", so there probably is no individual charge control for every single cell. Well, what can you expect for 8 $...

But more important, the charging current looks a bit high for me. Fine for AA, but not for N cells. Reading the description I'm not completely sure, but it looks like you get 300 mA only with 3 or 4 cells, which I would consider somewhat high for an 500 mAh N battery. Especially if you do not know which kind of charge control the device uses – if any at all. Using N-AA adapters I would not count on the mentioned overheat protection.

Dieter

[Dieter]

(07-27-2016 01:15 AM)Dave Frederickson Wrote:  In a 41 I don't think the button matters, as the 82120A also has flat contacts. In a clamshell, where two of the cells are stacked, you probably want a button top.

The 41 may not care whether it gets flat or button top cells. But you charger will. ;-)

Dieter

[smp]

(07-27-2016 07:17 AM)Dieter Wrote:  The description says "only charge batteries of the same size, capacity and technology at the same time", so there probably is no individual charge control for every single cell. Well, what can you expect for 8 $...

But more important, the charging current looks a bit high for me. Fine for AA, but not for N cells. Reading the description I'm not completely sure, but it looks like you get 300 mA only with 3 or 4 cells, which I would consider somewhat high for an 500 mAh N battery. Especially if you do not know which kind of charge control the device uses – if any at all. Using N-AA adapters I would not count on the mentioned overheat protection.

Thanks very much, Dieter, for your thoughts on this. I am already convinced that the BC-700 is the right way to go. Now, I am trying to make sure that the batteries will be able to make proper contact with the charger.

Can anyone offer an alternate N size NiMH battery with a button top?

Thanks!
smp

[rprosperi]

(07-27-2016 10:55 AM)smp Wrote:  Can anyone offer an alternate N size NiMH battery with a button top?

I bought some here: http://www.interstatebatteries.com/Produ...ucts).aspx

They all appear to be made by the same mfr, though I'm not sure. Note that the shipping (in USA) seems to be a fixed price of $ 11.95 for ground, regardless of order size (12 pcs and 48 pcs orders were the same).

[Dave Frederickson]

(07-27-2016 07:20 AM)Dieter Wrote:  

(07-27-2016 01:15 AM)Dave Frederickson Wrote:  In a 41 I don't think the button matters, as the 82120A also has flat contacts. In a clamshell, where two of the cells are stacked, you probably want a button top.

The 41 may not care whether it gets flat or button top cells. But you charger will. ;-)

Dieter

Using the adapters above, the charger makes contact with the adapter, not the battery. The adapter has a "contact" installed which has a shaft about 1/8" in diameter that makes contact with the battery. So the adapter will work fine with either button or flat top cells.

Dave

[smp]

(07-27-2016 01:15 PM)rprosperi Wrote:  

(07-27-2016 10:55 AM)smp Wrote:  Can anyone offer an alternate N size NiMH battery with a button top?

I bought some here: http://www.interstatebatteries.com/Produ...ucts).aspx

Thanks a million, Bob! That looks great, and, hopefully, I can go to a local brick-and-mortar Interstate Batteries location to avoid shipping charges, too. At least, I'm glad to have another option.

smp

[smp]

(07-27-2016 02:17 PM)Dave Frederickson Wrote:  Using the adapters above, the charger makes contact with the adapter, not the battery. The adapter has a "contact" installed which has a shaft about 1/8" in diameter that makes contact with the battery. So the adapter will work fine with either button or flat top cells.

Thanks very much, Dave. I've not been having any luck with finding the N size to AA size adapters, so far. I've run into out-of-stock messages from specific vendors, and on eBay and Amazon, I seem to be able to find every-other-size to every-other-size *except* N size adapters. SIGH.

If anyone has a good pointer for me, I'd appreciate it.

smp

[Dave Frederickson]

(07-27-2016 02:26 PM)smp Wrote:  

(07-27-2016 02:17 PM)Dave Frederickson Wrote:  Using the adapters above, the charger makes contact with the adapter, not the battery. The adapter has a "contact" installed which has a shaft about 1/8" in diameter that makes contact with the battery. So the adapter will work fine with either button or flat top cells.

Thanks very much, Dave. I've not been having any luck with finding the N size to AA size adapters, so far. I've run into out-of-stock messages from specific vendors, and on eBay and Amazon, I seem to be able to find every-other-size to every-other-size *except* N size adapters. SIGH.

If anyone has a good pointer for me, I'd appreciate it.

smp

What's wrong with the Ogaz adapters, above? Bob emailed them as I suggested and they're making a new batch.

Dave

[smp]

(07-27-2016 03:15 PM)Dave Frederickson Wrote:  What's wrong with the Ogaz adapters, above? Bob emailed them as I suggested and they're making a new batch.

Hi Dave,

Nothing wrong with them at all. When I went to the web site, they said out-of-stock.

Did they indicate to you when about they will become available again?

Thanks,
smp