ROP - Another battery option - 1/2D NiMh

Half sized NiMh 2600mA D cells are available at all-battery.com (and possibly other places I have not found) for $5 each or $4.60ea for five. Total of $28 for all six. I don't know what their shipping is.

For those that don't like Li-Ion and/or the AA battery carriers, you can make a stick of six 1/2D's for a 3D Mag or just load them loose. Easier to load and maybe higher current capacity than AA setups. Maybe. That is if similar capacity AA's are more current limited than their shorter and wider brethren.

They are tabbed though, so I don't know how stackable they would be loose. Anyone know how tabbed batteries handle being stacked up unsoldered??

Just thought I'd let people know. Seems like an easy option, and I have never thought I was getting enough out of my 6x Sanyo 2700 AA setup.

Any idea where else I could find 1/2 D NiMH batteries? I know they gotta come in more then 2600mA.

Those are NiCd's. Will six fit though? They're about 6 or 7 mm more than half a D size. Is there that much room for an extra 36 to 42mm in a 3D mag? This would be an easy battery path for the ROP if it works.

Actually I think you'll find that the battery stick for a Streamlight SL-20 or a Mag Charger is about the same length as the 3 D batteries. And those are made from 5 1/2D NiCD batteries.

Actually... I want to put 7 in my 4d ROP mag...

you can get 3500mah & 4000mah NIMH from www.batterieswholesale.com but you'll need one of fivemega's 37mm D cell extenders. Not bad - 3 1/2 D length with 1hr + on high and they can handle the 4 amps without an issue

I have used tabbed batteries. I usually cut the tabs down a bit and overlap them to form a "nipple". They work fine that way.

Bill

RickyT said:

Those are NiCd's. Will six fit though? They're about 6 or 7 mm more than half a D size. Is there that much room for an extra 36 to 42mm in a 3D mag? This would be an easy battery path for the ROP if it works.

Click to expand...

Good catch, I didn't see that length difference - silly me, I assumed half size meant half sized.

A 4D Mag may fit seven of them with the spring removed or shortened.
4 x 60 = 240, 7 x 37 = 259. You need to get another 19mm out of it, which you may be able to get by using the 2 x 18650 into 2C Mag method of removing the spring and removing some anodizing for the lower tab to contact. This may need a small magnet or other shim.

Too bad I don't have a 4D Mag.

This is just speculation because I don't know how these cells are rated. The site says "Rapidly charging at 1C rate and reliable cycle life up to 1000 times at 0.2C rate." That doesn't sound like a high discharge rated cell description.

One of the nice things about the ROP is that it's usually a 6 cell set up. We pay for that low voltage with high current. A proper ROP is going to draw 4.3 amps. At startup the surge may be ~ or > 10 amps (where's Andrew Wynn when I need him?) I wonder if these NiCad cells can handle that. I have some doubts.

If they can handle it with minimal/acceptable sag then it's likely 7 of them would flash a ROP bulb. Some have mentioned that for 7 cell ROP set ups should be relagated to AA NiMh. That sounds reasonable to me. In fact I've blown a ROP bulb with 7 little IB1400 2/3 A cells. Of course, they have a massive discharge capability for their size.