Need D size, 32650, 26650, 18650 or AAA, AA rechargable batteries with converter suggestions (India)

[nOne]

@Rexlion

My memory was off; the Centura D is 8Ah, not 10. All Eneloop (name brand) cells I’ve ever seen are rechargeable NiMH, and low self discharge to boot. I assume you are trying to get away from using disposable cells such as alkalines.

Tenergy Premium D 10000mAh NiMH Rechargeable Batteries, 4pk - Tenergy
Tenergy Centura D 8000mAh NiMH Rechargeable Batteries, 4pk - Tenergy
it is so much confusing, which to choose. Not only from this brand and others too.
EBL D Size Rechargeable Batteries D Cell 10000 mAh NiMH Battery (Multicolour) - 2 Counts : Amazon.in: Home Improvement
BONAI Rechargeable D Size Batteries 10000mAh 1.2V Ni-MH with High Capacity (4 Pack) : Amazon.in: Electronics
As per my application I don't think I need high discharge battery for Gas Geyser compared to existing Zinc–carbon (which lasts 70 days, daily 10 uses, 5 sec/use)

@xxo

For AAA and AA’s I like Fujitsu NiMH - these are the same as Japanese eneloops (Fujitsu makes eneloops in their factory). Eneloops are fine if you make sure that they are made in Japan and are not fakes (a lot of them are fake and some eneloops are now made in China). For C and D cells, low self discharge NiMH from Soshine work well, Tenergy centuras are OK too but have a little lower capacity. For Li-ion 14500, 18650, 21700 and 26650’s, I like protected Keeppower cells.

Fujitsu NiMH, interesting info. Thank you for sharing.
Original eneloop available here in India. I will buy that only.
Panasonic eneloop AAA Rechargeable Battery, Pack of 4 : Amazon.in: Electronics
Panasonic eneloop AAA800 mAh Battery - Panasonic : Flipkart.com
Panasonic eneloop AA Rechargeable Battery, Pack of 4 : Amazon.in: Electronics
Panasonic Eneloop AA 2000 mAH Battery - Panasonic : Flipkart.com
Panasonic eneloop Pro AA Ni-MH Rechargeable Battery with 2550 mAh Capacity - Pack of 4 - BK-3HCCE/4BN : Amazon.in: Electronics
Panasonic Eneloop Pro Battery - Panasonic : Flipkart.com

For c and d size: (D size batteries are 2200–12000 mAh as per Wiki)
You are suggesting this Soshine 11000 mAh
Soshine D/R20 Size Rechargeable Batteries NiMH 11000mAh - Soshine
Is this will be good or Tenergy premium, centura or EBL or bonai??

@Correllux

I think before you go any further you need to learn what requirements that device has. An email to the manufacturer or sales distributor might get you the information you need. First, you definitely need to know the acceptable voltage range of the power circuit. Some devices accept a range and can handle over-voltage to a small degree…some can’t and you risk blowing fuses or damaging the components. Whether the batteries are set up in series or parallel can give you a hint but not confirmation. Second, you need to know approximately how much current the device uses. If it isn’t a lot and if it can handle 4.2v then perhaps you could run a single lithium-ion cell in there although that may not be as much capacity as the two D-cells provide. If the device handles lower voltage ok, then a couple of the good quality NiMH D-cells might be your best option - the good ones have 9,000mAh or more and can handle typical current draw on boards without too much voltage sag. Those are around 1.45v off the charger and usually peter out around 1.0 to 1.1 volts. If the device gets unhappy with less than 1.3 or 1.2 volts then NiMH is probably not a good option, but you could just recharge them more frequently if they aren’t draining too quickly. I wouldn’t shop for cells before you know this basic important information about the device. They seem expensive enough (about $100 USD) that I wouldn’t want to risk damaging them. If there are fuses, sometimes those are surprisingly expensive, too, depending on what type and size.

Arc generator or gas lighter circuit, I checked with 5v 1A DC adapter which works good, but i fear about the voltage. So NiMH is good for it 1.2+1.2=2.4v compared regular 1.5+1.5=3v.
I tried 5v 1A charger worked, 5v 2A worked (fast gas lighter generation) it did not worked above that on 9v and on as I checked connecting direct wires with DC adapter.
I am sure that batteries are in series, as I can see the internal connections and +ve and -ve terminals of battery with naked eye, after removing the geyser cabinet.
I don't know how much current it draws, I think max 2A but not sure.
And about circuit protection, for gas geyser, generic and original lighting circuit is easily available locally so no worry. Also protections are provided which worked as well as I check voltage 9v (18 watt charger) it didn't worked and nothing happened to circuit or geyser. So all well.

Any suggestion for D cell NiMH other than these - Soshine, Tenergy premium, Tenergy centura, EBL, bonai.

18650 battery suggestions remaining. Some of them I selected Indian online store,
primary applications will be 3V-5V 3A diy arc generator, arc plasma gas lighter circuit, replacing very old Dell D530 laptop battery 6 li-ion cell, 11.1V, 56WH (year 2007) (Type M9014)
secondary applications diy power bank and some other stuffs.
3.7V 2600mAH Lithium Polymer (Li-Po) Battery - 18650 Model - Samsung
Li-Po Battery-3.7V/2600mAH-Model 18650-Samsung | Sharvielectronics: Best Online Electronic Products Bangalore
3.7V 2600mAH Lithium Polymer (Li-Po) Battery - 18650 Model - Samsung - componentstree
LG 18650 MJ1 3500mAh (3c) LI-ION BATTERY - Robu.in | Indian Online Store | RC Hobby | Robotics
Buy Original LG 3200mAh 10A 3.7 Volt Li ion Battery at Low Price
Buy Original SAMSUNG 3.7 v Li ion 2500mAh 18650 Battery In India
Buy SAMSUNG 18650 26J 2600mAh Li ion Battery Online | Robu.in
Buy Original LG 2600mAh B4 18650 Lithium Battery In India | Robu.in
Buy Original SAMSUNG 30Q 18650 3000mAh Battery In India
Buy Original LG 2600mAh M26 18650 Lithium Battery In India | Robu.in
Buy Original SONY VTC6 18650 3000mAh Li ion Battery In India | Robu
Buy Original Panasonic NCR18650B 3400mAh Li ion Battery In India
Buy Original Panasonic NCR18650B 3400mAh Li ion Battery In India

As I said in 1st post after watching YouTube comparison I selected LG MJ1 but there are more batteries available compared in this old video. So guidance needed.