LSD batteries?

[metlarules]

I noticed alot of threads lately on LSD D cell batteries. My question is: Are we overlooking the obvious? Those Accupower cell are 24 bucks for 2.http://thomasdistributing.com/shop/...html?SP_id=&osCsid=2uqp7bh9c83o0km6dvollqt274 Nicad d's are 5 bucks apiece for 7mah cells.http://www.batteryjunction.com/r1ed-gd7000.html. You get 5cells for a grand total of 35000mah for the same price as 2cells total 20000mah. What exactly am I missing here? Nicads are the original lsd batteries and are more durable than nimh. Just my observation. I am looking forward to your replies.

 

[etc]

Nicads are obsolete. I too wonder why. But they are. I think maybe capacity has something to do with it.

 

[lctorana]

Yup, NiCads are obsolete.

Woo-hoo! Stock up!

 

[Sub_Umbra]

Yup, the NiCDs are obsolete -- I love them. I've got quite a few 7,000 mAH NiCD Ds and they are a great value for the money. By the time I need to move on to LSD D cells they should be mainstream but I won't be running out of NiCDs soon...

We actually use NiCD Ds, Cs and AAs in quite a few applications. They lose less of their capacity in the heat OR cold than their NiMH counterparts. NiCDs (and their chargers) have been around for over 100 years and they are pretty well thought out.

 

[bob_ninja]

You just found a pricing anomaly. It has to do with volume. C and/or sub-C format in NiCd has huge volume for old battery packs for power tools. They are now moving to Lithium chemistry but still make a lot of old NiCd based packs. I imagine that some packs also use D format. So there is probably a decent production volume for them as well.

On the NiMH side there is much less volume for C/sub-C/D formats. I know of a single pack for iRobot bots that use C/sub-C NiMH cells. Most common Energizer D cells are actually sub-C or AA packaged into a spacer.

So volume for NiMH Ds is so low that prices are much higher. Thus as you discovered NiCd Ds are a far better value than NiMH Ds. As for low production volume for NiMH Ds, I have no clue why.

I have plenty of children toys and few other gadgets using Ds that I would love to use NiMH in them. Instead I chose to get a bunch of cheap Eneloops and use D spacers:

Single D: 10Ah @ $24
Eneloops, 4pk @ $9, 2.6pk @ $24

Single D 10Ah @ $24
2.6pk of Eneloops, 2.6 * 8Ah = 21Ah @ $24

Again, no brainer. I have to change AAs more often, of course. But I don't care. I have more than enough spare Eneloops available. And D/C adapters I can reuse forever.

 

[metlarules]

As I see it the only advantage nimh has over nicad is ease of charging. Just drop it in the charger and top it off. Nicads like a complete discharge first. I guess I'll just keep enjoying my "obselete"nicads for the time being.

 

[Marduke]

And capacity. nicads have a much lower capacity.

 

[metlarules]

And capacity. nicads have a much lower capacity.

The capacity of nicad d cells are up to 7000mah. The capacity of most nimh d's is 10000mah. I can buy 5 nicads for 2 nimh. 35000mah for nicads
20000mah for nimh.Seems a good value to me. Yes,I'm a cheapskate.:nana:

 

[lctorana]

Yes, capacity.

In AAA size, the capacity gap between NiMH & NiCad is huge. Triple.

In AA, it's double.

Then as you go to bigger cells, the gap closes.

And when you factor in the lower self dischage of NiCads, the gap closes further.

And the price differential - puts NiCad ahead, IMHO.

And I woud trust NiCads to have a longer service life.

For some strange reason, Jaycar sell two 5Ah D cells, sie by side, for the same price. One Nicad, one NiMH. Why would anyone buy the NiMH one?

 

[MrAl]

Hi there,

NiCd's are also being phased out because of environmental issues. In the
future sometime we might see them only very rarely.

 

[jayflash]

Am I correct to think NiCd's lower internal resistance will narrow the gap of capacity rating compared to NiMH in very high drain use? For example will a 5Ah NiCd provide closer to that rating than a 10Ah NiMH cell at high drain? Might the NiCd provide 3 - 4Ah compared to maybe 5 - 7Ah for the NiMh?

 

[bob_ninja]

Am I correct to think NiCd's lower internal resistance will narrow the gap of capacity rating compared to NiMH in very high drain use? For example will a 5Ah NiCd provide closer to that rating than a 10Ah NiMH cell at high drain? Might the NiCd provide 3 - 4Ah compared to maybe 5 - 7Ah for the NiMh?

Yes. It depends on the application. For general electronics that need a modest current then the total energy supplied by NiMH is greater. However, for high drain apps, say a battery operated power tool that need 2C-4C and peak 6C (just making up numbers here) then NiCd provide more total energy.

Hence most older power packs for tools like drills and saws use NiCd.

 

[Unforgiven]

Note: [Commerce related posts removed]

 

[metlarules]

I take it that nicad would be a better choice for some of these hotwire mods than nimh. Correct?

 

[lctorana]

You're going to hate this answer, but it's "maybe yes and maybe no".

If it's AA cells you are talking about, then that's a definite NO. Eneloops or similar will do everything a Nicad will do with double the capacity qand even lower self-discharge.

If it's D cells you are working with, then possibly yes, but it depends on what NiMH & NiCad Ds you can get your hands on.

And so on. No single right answer. Life's like that sometimes.

 

[Sub_Umbra]

...If it's AA cells you are talking about, then that's a definite NO. Eneloops or similar will do everything a Nicad will do with double the capacity qand even lower self-discharge...

Emphasis Mine.

With the exception that an Eneloop will only do it half as many times as a NiCD.