Nicd battery Ah calculation

[caphair]

So I found my old Craftsman 19.2v C3 battery for a 1/2” impact driver.

When this was “new” it performed terribly. Barely able to get more than 4 lug nuts off before dying. I always attributed it to the battery itself.

Now they have lithium ion equivalent replacements with 5-6Ah capacities. This made me curious about the capacity of the nicd.

Couldn't find any specs on this battery and the ones I do find are rated at 3.6Ah but the sticker on the battery says 29Wh. Doing the math (29/19.2) gives only 1.5Ah.

So am I missing something here or are the specs online misleading? The 1.5Ah would make sense why the tool barely performed

[televizora]

Re: Nicd battery Ah calculation

NiCd cells are notorious and famous for their memory effect and low capacities.
Typical NiCd cells have capacity of about 600-700mAh. Or less.
My first cordless drill was cheaper one and came with NiCd battery.
I don't even need to tell you how much better performed my second drill with LiIon battery. 10x better.
NiCd batteries are huge, while their actual capacity is miserable. Only most cheaper tools come with NiCd.
Or extremely old ones. You can either get rid of the NiCd and replace them with NiMh or LiIon, complemented with controller
You also cant just use any batteries. Power tools need batteries with high peak discharge rate.

[eccerr0r]

Re: Nicd battery Ah calculation

One thing that has gotten "better" is that battery management is now mandatory with lithium ion cells. You or the store probably mistreated the battery pack and killed it, but NiCd cells don't go up in smoke when mistreated, they just ... stop working very well. I also have a NiCd based drill that simply doesn't work all that well, it's actually quite difficult to maintain NiCd cells if you don't use it frequently.

1.3Ah NiCd cells are common for battery packs (sub-C-sized). I've seen 5AH "D" sized NiCd cells (used in old laptops).

[caphair]

Re: Nicd battery Ah calculation

I barely used it but the times that I did it seemed to lose any useable power quickly for an impact driver on 80 ft/lb lug nuts.

What’s the best way to store these? I’ve read conflicting info stating to fully discharge them before storing and others saying to fully charge them first

[stj]

Re: Nicd battery Ah calculation

NiCd is still used for emergency lighting,
i think it's because of the temperature range or cycle count being far better than NiMH.

but yes, capacity by weight/volume is crap.

[eccerr0r]

Re: Nicd battery Ah calculation

NiCd is pretty much obsolete these days due to RoHS.
It has very good cycle life, but the thing is, it needs to be cycled/used. I don't see a reason for using NiCd for emergency lighting, seems like the worst possible place to use them. SLA is one of the better options for emergency use, if it weren't so heavy per watt hour.

After thinking about this for a while, the mere act of storage is about the worst thing you can do with NiCd cells. For the end user, it's near impossible to store NiCd cells in the best possible situation: cold, disconnected and disconnected from each other. When you need to weld them together for high current draw, this ruins the need for them to be disconnected from each other for storage.

After thinking about a lot of battery technologies, it seems the best "fire and forget" state of charge you should leave batteries for storage is have them charged. For lead acid, 100% charged, but all other chemistries, 50% to 70% charged. Though storing NiCd cells at 5 to 10% is actually better, it's impossible to do this accurately, and having them charged is better.

NiMH, NiCd; pack - best to keep low charge in storage, err on higher state of charge - MUST recharge completely before using.
NiMH, NiCd; cells - flat during storage is OK, obvious to recharge before using.
Li-ion; pack or cells - keep 50% charged in storage - recharge to 50% if it goes low, OK to use right away when taking out of storage if it still have charge.
Lead-Acid - charge to 100% before storage and recharge to 100% every few months, OK to use right away.

[televizora]

Re: Nicd battery Ah calculation

It has very good cycle life, but the thing is, it needs to be cycled/used

Almost all of the NiCd batteries of my power tools died prematurely. LiIon are better in every way, especially if you occasionally use them,

[eccerr0r]

Re: Nicd battery Ah calculation

That's exactly the problem, an idle NiCd is more likely to get damaged. If it's used (and also properly balanced), it lasts longer. But NiCd never had battery management to help out with balancing and protection, this would have increased their usable lifetime significantly, alas, though plastic may melt, NiCd won't ignite if improperly treated.

Li-ion requires management else you may end up with flames. But indeed Li-ion tends to last longer if you don't use it...

[sam_sam_sam]

Re: Nicd battery Ah calculation

This made me curious about the capacity of the nicd.
1.5Ah would make sense why the tool barely performed

Here is where you can find some high quality Sanyo sub c batteries
But they are not cheap $5.00 a cell

https://www.osibatteries.com/sanyo-k...-nicad-battery

These are a little higher in cost when you can find them
They also have 3000 milliamperes hour batteries but would have do a lot of
Google searching to find better prices

http://store.batteriesamerica.com/hr...tterycell.aspx

But they are not cheap from $6.00 up to $7.00 a cell

I personally use the 2500 milliamperes hour batteries for the best results from eBay but I just looked an there are none for sale right now but from time to time you can find them on eBay

I have had very good results with 1800 milliamperes hour batteries if you can not find the 2500

Disclaimer

I have not bought anything from either websites stores so I can not tell you anything about how good there products and if they OEM are knock offs but the pictures look like are real products

All other batteries that are sold on eBay are crap to some what decent but it hit and miss and very hard tell what decent quality and what just plan crap

I hope this helps

[RJARRRPCGP]

Re: Nicd battery Ah calculation

When this was “new” it performed terribly. Barely able to get more than 4 lug nuts off before dying. I always attributed it to the battery itself.

Nicds are known for dying with high load, just like that!

[sam_sam_sam]

Re: Nicd battery Ah calculation

Nicds are known for dying with high load, just like that!

One problem is most of time they used Chinese made batteries which are most of time they are crap

( do not get me started about the quality problems that I have seen and know about )

That why before lithium ion batteries

I would buy Sanyo batteries and just use these batteries instead of the batteries that were in the packs

But even lithium ion batteries have there own problems if you over current them for too long that shortened there life and they will not last long

I have done this before and either one of two things happens either some of the cells go bad or the mosfets on the battery balancing protection board go bad

I have a Milwaukee 14 volt in pack gun that is only nicad batteries that I have used the 2500 milliamperes hour batteries I can use it a lot before having to charge it

They have more power and last longer

They are also most as good as the 2 amp hour lithium ion battery packs as far as how much power they will put out

One note they do not use the same type batteries in the 2 amp hour battery as do in the 4 amp hour battery version ( the 4 amp hour battery version has a higher current output rating than the 2 amp hour battery version

Now I would agree with you that a 4 amp hour lithium ion battery pack does not even compare in how much power output it has

[dmill89]

Re: Nicd battery Ah calculation

Here is where you can find some high quality Sanyo sub c batteries
But they are not cheap $5.00 a cell

https://www.osibatteries.com/sanyo-k...-nicad-battery

These are a little higher in cost when you can find them
They also have 3000 milliamperes hour batteries but would have do a lot of
Google searching to find better prices

http://store.batteriesamerica.com/hr...tterycell.aspx

But they are not cheap from $6.00 up to $7.00 a cell

I personally use the 2500 milliamperes hour batteries for the best results from eBay but I just looked an there are none for sale right now but from time to time you can find them on eBay

The problem is that for not much more (or possible less depending on what cells you use) than the cost of rebuilding the battery with "quality" cells you could just buy a newer more powerful tool that has Li-Ion batteries to begin with.

I believe the earlier (the ones that came with NiCads) Craftsman C3 1/2" impacts were rated at 200 ft/lbs. (the later/"premium" ones that came with Li-Ion batteries were rated at 300 ft/lbs.).

For $100 you can get the Ryobi 1/2" impact with 4.0 Ah Li-Ion battery rated at 300 ft/lbs.: https://www.homedepot.com/p/RYOBI-ON...261K/313581565

Or for $150 (list, though I've seen leftover inventory from Christmas marked down to $99 at my local Home Depot and picked one up myself for that price) you can get the Makita 1/2" impact with 3.0 Ah Li-Ion battery rated at 325 ft/lbs.: https://www.homedepot.com/p/Makita-1...04S1/313962631


So paying $80-$112 plus your time to fix an old less powerful tool doesn't make much sense, the only real logical options would be either to chance it with a cheap amazon/e-bay "Knock-off" battery (you might get lucky, you might not), or just "bite the bullet" and buy a new Li-Ion powered tool.

[stj]

Re: Nicd battery Ah calculation

dont forget that ikea sells a 4pack of rebranded 2400mAH eneloops for about €5

[televizora]

Re: Nicd battery Ah calculation

dont forget that ikea sells a 4pack of rebranded 2400mAH eneloops for about €5

Don't forget that you can't use "any" battery. For example, some years ago I tried to replace NiCd batteries in one of my cordless drills with LiIon. Used LiIon cells from old laptop batteries, after testing which are still good. But they were unable to provide the required current. You need batteries with high peak discharge current. And knowing that one good 18650 battery is about 8$...And I need 8 or more...
I bought another cordless drill that comes with LiIon battery and it is much more powerful. Not only this, but the spare batteries are cheaper than refurbishing/rebuilding the battery myself. Manufacturers got significant quantity discounts.

[stj]

Re: Nicd battery Ah calculation

eneloops can push some current - i have a datasheet.
also, because they are AA you can pair them up.

[eccerr0r]

Re: Nicd battery Ah calculation

Honestly I think there's a conspiracy against self battery packing (building your own packs)... well one thing is the balancing aspect (other is connectivity), but I doubt even cell sellers sell you balanced cells to begin with, you have to test yourself? And liability if something goes up in flames?

Sigh. So many things I have that could use new battery packs/cells...

[caphair]

Re: Nicd battery Ah calculation

The problem is that for not much more (or possible less depending on what cells you use) than the cost of rebuilding the battery with "quality" cells you could just buy a newer more powerful tool that has Li-Ion batteries to begin with.

I believe the earlier (the ones that came with NiCads) Craftsman C3 1/2" impacts were rated at 200 ft/lbs. (the later/"premium" ones that came with Li-Ion batteries were rated at 300 ft/lbs.).

For $100 you can get the Ryobi 1/2" impact with 4.0 Ah Li-Ion battery rated at 300 ft/lbs.: https://www.homedepot.com/p/RYOBI-ON...261K/313581565

Or for $150 (list, though I've seen leftover inventory from Christmas marked down to $99 at my local Home Depot and picked one up myself for that price) you can get the Makita 1/2" impact with 3.0 Ah Li-Ion battery rated at 325 ft/lbs.: https://www.homedepot.com/p/Makita-1...04S1/313962631


So paying $80-$112 plus your time to fix an old less powerful tool doesn't make much sense, the only real logical options would be either to chance it with a cheap amazon/e-bay "Knock-off" battery (you might get lucky, you might not), or just "bite the bullet" and buy a new Li-Ion powered tool.

I wonder if the newer 300 ft/lbs is attributed to the higher power available from li-ion battery or if it was actually redesigned? Might be tempted to just try a li-ion pack in there and see what happens

[eccerr0r]

Re: Nicd battery Ah calculation

Redesign. Torque of a impact wrench is disjoint from battery power, but total tool power is correlated with battery power.

[sam_sam_sam]

Re: Nicd battery Ah calculation

I wonder if the newer 300 ft/lbs is attributed to the higher power available from li-ion battery or if it was actually redesigned? Might be tempted to just try a li-ion pack in there and see what happens

The only way you are going to get the most benefit out this type of tool application is to use the 9 amp hour battery pack version ( the cost of this battery is about $150.00 each when they have a special buy )

One note is this

only use this at maximum load power for short periods time because you will trip the over current or temperature over load devices for the battery and or tool

Yes the battery has the power but the tool dose not have as much power as the

Milwaukee impact ( High Torque Impact Wrench 700 foot pounds gun ) does but you still have to get the most powerful battery that they make for the best performance ( in order to trigger the temperature or over current over loads you would have to abuse the intent of how to use this type of tool you do still have to use in short burst intervals not just holding the power button until the bolt comes free ) you can just do it longer periods of time before you trip the over load

This one has the power but if you are continuing using it for High Torque Impact application like removing rusted bolts you will run the battery down very quickly and 50% battery power available does not have the same power when fully charged

( one note this is very hard on the battery and the tool you will wear out the brushes very quickly depending on much you use it for high torque application )

The high amperage battery that they have is a 12 amp hour battery this battery runs around @199.00 when they have a special buy at Home Depot

I have used both tools and depending on what you are trying to do depending on which tool I would use

The Milwaukee impact gun has one draw back and it this yes it has the power with the highest amperage battery pack but with this setup the weight of the tool and the battery making removing a lot of bolts going to give you a work out it weight quite a bit

I hope this helps

[eccerr0r]

Re: Nicd battery Ah calculation

Sad, I only have a 250 ft*lb pneumatic impact wrench