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Why Sub c batteries used in battery packs for drills? Answered

Is this somehow related to discharge rate? I'm trying to replace existing sub c batteries, but their price is put me off. Can anyone provide some info? If use equal capacity aa, what the difference gonna be (once again discharge rate)?
I would  really appreciate any info about this.



6 years ago

Thank you reply guys.

My current battery pack contain 10 cells sub c 4/5 and rated 1.2 Ah. (it's Bosch 12V drill battery pack)

My question is what maximum current can Nicd and nimh batteries supply? From google, there is info that NiCd batteries can provide higher current than nimh, but there is absolutely no figures to confirm this.

the dewalt 18v nicad cordless is rated at 400w. P=VA 22 amps
dewalt 12v nicad 240w so 20 amps.
18v li ion drill 350w. 19.4 amps
20- 25 amp max current maybe from subc batts.

Each battery type can come in a range of Ah ratings. The Sub C NiCds seem to top out at 2Ah while the NiMh look to go from 3.8Ah to about 5Ah. It all depends on how long you want the batteries to last and how much you want to pay for them. It looks as though Bosch used a cheaper set of batteries to build the battery pack. So going from 1.2Ah to 2Ah batteries would be a nice improvement. But if your willing to spend $5 a battery for the NiMh rated at 5Ah then you can have a huge improvement. So do you want more power for about $20 or are you willing to go the extra mile and get more then twice the power for more then twice the price?

The Ah ratings i listed are the highest ratings i could find for sale online for each battery type. They could go higher then that but i doubt it. But advances in batteries are being made all the time. Though its safe to say NiCds have pretty much reached there limits and research has moved on to better options. So just get the highest Ah rated batteries you can find/afford.

You seem very knowledgeable so I will ask you this. I have a cordless tool set that uses a very unique design 18 volt battery pack. It is of the NECK design with 3 FLAT contacts around the NECK, FLAT to the rear. Inside are 1 sub c in the neck and 14 cells in the body, 5cells.4 cells, 5 cells stacked in a pack plus 1 equals 15. Do you know if I can buy a preassembled pack in this configuration? I have sean some with two cells for the neck. That pack will not work in my "BOX". If tis pre assembled pack is not available I might as well buy the packs from the vendor. Single cells I solder together is more $s than from the vendor. Any help welcome. reeltoreelguy@gmail.com

Buy the packs from the vendors or solder your own pack together.

Compair the mAh rating of the batteries. Typically the smaller the battery the lower the mAh it has so it will have less capacity then the larger batteries.

If we are comparing NiCd batteries then the sub C offer about 2000mAh while the AA only offer 700mAh. Now how much fast the AAs will loose there charge compared to the sub C will depend on how many amp the drill draws. But its safe to say the sub C will last more then twice as long as the AA.

I assume you don't live in the USA. Since i'm finding 10 packs of sub C batteries going for about $26. Unless your trying to upgrade the pack to NiMH. In which case you may need to upgrade the charger while your at it.

On the average, the smaller the battery (if the same chemistry / type) the less power and quicker the discharge rate.