Difference between 3500mah & 2Ah Ni-CD 18v Batteries for Bosch Drill

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3puttssuck

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#217732 10-Jul-2017 14:38

Whats is the difference between these 2 batteries?

Is one stronger than the other output wise?

http://www.trademe.co.nz/building-renovation/tools/power-tools/batteries-chargers/auction-1367646911.htm

http://www.trademe.co.nz/building-renovation/tools/power-tools/batteries-chargers/auction-1365085816.htm

TIA

timmmay

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#1818897 10-Jul-2017 14:45

One has more capacity, in that it will last longer between charges. Other than that they're both 18V so should work fine. I'd search for opinions on the brand before purchase.

3puttssuck

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#1818898 10-Jul-2017 14:48

timmmay:

One has more capacity, in that it will last longer between charges. Other than that they're both 18V so should work fine. I'd search for opinions on the brand before purchase.

Thanks, but which one has more capacity?

richms

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#1818899 10-Jul-2017 14:48

Nicd vs ni-mh cells.

Need to know the actual cells used to look at the data to see internal resistance to know either way which will have more power.

Often nicd ones do, but not always the case.

Richard rich.ms

kryptonjohn

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#1818922 10-Jul-2017 15:14

But 3500mAh NiMH is 3.5Ah vs the 2.0Ah NiCd so 75% more capacity.

Plus NiCd are awful - memory effects and toxic.

MikeAqua

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#1818928 10-Jul-2017 15:25

One is 3500mAh = 3.5Ahr

The other is 2Ah.

As they are both operating at 18V then the 3.5Ah has 75% more nominal capacity.

Actual capacity will depend on resistance as stated by others and has to measured.

Also battery management systems can limit discharge which affects usable capacity.

Mike

richms

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#1818931 10-Jul-2017 15:29

nimh has higher self discharge which means when you grab it off the shelf it may be flat.

And the dinosaur chargers dont turn off or maintain batteries so you cant leave them in there without cooking them. Nicd can be good to go months after charging them which may be more useful than a long run time. Memory effect is largly a non issue in drills. It is for things like cordless phones where they get the same cycling day after day and usually after the partial discharge get cooked in a crappy charger.

Richard rich.ms

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1101

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#1818956 10-Jul-2017 16:12

if you want it to last.....

You need to get one THAT MATCHES YOUR CHARGER , ie either Nicad or NiMh , whatever the charger was designed for

Dont use NiMH with a trickle or overnight or dumb charger, it wont last . Nicad is more resilient with 'dumb' chargers
Nicad & Nimh also have different charge cutout points if using a smart charger, so again batt has to match charger .

Also, expect rated capacity of generic batts to be a load of old BS .
And as stated above , if it has high internal resistance , voltage will drop under load (so will have less power)

In general, NICAD not so bothered if you discharge them right down to Zero. NIMH can be ruined if discharged down to zero
NICAD not so fussy with chargers , NIMH fussier with chargers(if you want it to last)

Have you priced up a genuine replacement part ?
Or even better , even a cheap Lithium based Drill instead , given the cost of those batts in your links .

richms

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#1818968 10-Jul-2017 16:29

Ive heard good things about the ozito power xchange ones at bunnings. Not bought because I am too invested in Ryobi and Milwaukee stuff but people I know with them are very happy for a sub $200 setup. The cheap ryobi set is a piece of junk drill in it, but gets you going on the system.

Richard rich.ms