Rechargable battery suggestions?

I'm very happy with my Rayovac 1 hour charger. NiMh AA batteries are very inexpensive and have a high capacity 1800mah. Or you can pay an arm and a leg for some 2100mah batteries. I've used NiMhs in my brinkman rebel, and streamlight 4aa 7 LED lights and they are nice and bright. You are going to have differing results in different lights though. I think my SL 4aa is actually getting a little too much juice from these batteries and I might have to put a resister to calm the current down a bit. When it comes down to it your probably going to find that you will want different battery types for different situations. Lights that need alot of voltage are not going to do well with NiMh's. If you are thinking of just storing the batteries for long periods of time, forget about NiMh's.

If you want a good supplier of NiMh AA batteries, www.bydusa.com has a pack of 24 AA 1800mah for 29.99. I've dealt with them a couple of times now and the are fast to get stuff out.

That sounds like a great deal. I've switched to NiMH AAs for my TV/VCR/etc. remote controls. The shelf life is a drag, but my Maha charger gets 'em charged quick enough for me. And since I have about a dozen remotes and only need the special functions of a particular remote once in a long while, it's OK to just keep a couple pairs charged and move 'em around as needed. (Isn't it interesting how every piece of consumer gear comes with a "universal" remote but none of them can learn 100% of each other's functions? pain...)

My Cobra FRS radios run on 4 AAAs. I switched to NiMH for them as well, a single charge keeps them running for a decent 12 hours or so, long enough for my purposes. We use them to stay coordinated at my car club meets, at the race track, etc. With the charger in the car, it's a simple matter to recharge them for the next day's driving.

In general, things that don't get used frequently, and whose use you can predict in advance, are fine for rechargeables. For me, flashlights, being "emergency use" items, where you can't predict when you're going to need them, I'd stick with long life primary Lithiums. Unless you're the kind of person who uses your flashlights every day, in which case rechargeables make more sense. With my digital camera, again NiMH is the only way to go. On a trip I take a universal power supply along and recharge all the batteries each night. (That's a lot of charging - 4 AAs in the camera, 2 AAs in my MD recorder, plus spares for swapping in during the day if needed...)

Originally posted by MSaxatilus:
They seem to have a short shelf-life once charged, don't give you the runtimes of alkalines (dismal actually), don't give you the power of alkalines and flat out don't seem to be worth the money.

However, those were old Eveready NiCads. My question now is that since I've really started to get into the flashlight thing again, I was wondering if the new NiMh rechargeables or alkaline rechargeable (Rayovac) are worth the money.

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<font size="2" face="Verdana, Arial">They still have the short shelf life after charging, in most circumstances you'll still get shorter runtimes, and the lower voltage might still be viewed as "less power".

Rechargeables whether NiCd or NiMH, serve their purpose, but they haven't the advantages of primary cells any more than primary cells have the advantage of rechargeables.

As for rechargeable alkalines, think of them as refreshable alkalines rather than rechargeable. They're still primary cells, and other than a longer runtime in an emergency situation (which renders them exhausted and useless), general use is barely on par with a sustainable voltage regulated charged capacitor circuit.

In the past I've had rechargeable batteries for flashlights, electronics etc. and have not had much luck. They seem to have a short shelf-life once charged, don't give you the runtimes of alkalines (dismal actually), don't give you the power of alkalines and flat out don't seem to be worth the money.

However, those were old Eveready NiCads. My question now is that since I've really started to get into the flashlight thing again, I was wondering if the new NiMh rechargeables or alkaline rechargeable (Rayovac) are worth the money.

I would basically use size AA and AAA the most for flashlights and I have a GPS unit and a Marine Radio that are pretty battery intensive, expecially with the fall striped bass migration in full swing now.

Any suggestions or should I stick to normal Alkalines and lithiums?

Personally, I do not believe in putting NiMh in remote controls. Most remote controls will run on couple years on regular alkalines.

I use rechargeable for all my high drain applications (digital camera, daily used flashlights) and stick with alkalines for low drain such as clocks, remotes, small pocket radio (NOT tape player)

- Vikas

I tried the Ray-O-Vak rechargeable Alks. They are okay for walkmans and such and did save some money. I did have some problems with them. The Alks would sometimes leak, were inconsistent and at only 20 recharge cycles, are relatively more expensive than the new NiMh cells.
I have now switched to the Ray-O-Vac NiMhs and have been very satisfied with their performance. The NiMh cells seem to last almost forever. I have not had any leak and of the 20 or more cells I own, I have not had one fail.

As weather to use rechargeable bats or not, consider how often you go through a set of batteries. If it is something you replace batteries once or twice a year you might just stick with the Alks. If it is a flashlight for your car, lithium is the way to go. If you find you self replacing the batteries often The rechargeables are the way to go.

A flashlight with a fresh charged set of NiMh cells will usually be brighter than one with 10% consumed Alkalines.

I normally use NiMH's in the lights I use most often for the longest run times. I also use them in my C cell and 5 to 12 D cell lantern applications where I am more prone to wanting to top-off batteries after a night of use.

I normally use NiCad D's and 1/2D's in the big 5+ cell flashlights in which I keep 10 to 20 watt bulbs. I don't want to have to recharge these things more than once every two months.

I use rechargeable AA alkalines in a Surge I use frequently so I can "refresh" the voltage back to 1.5 V per cell frequently for maximum brightness. A Surge with fresh alkalines will draw about 5.3 Volts compared to only 4.8 volts with NiMH's.

Similarly, I use rechargeable AAA alkalines in my ARC AAA so that I always have maximum output.

The rechargeable alkalines last a long time when recharged after shallow discharges at relatively high alkaline currents (up to .45 Amps for AAA and .55 Amps for AA's.)

the only rechargeable AA leakage I've had is when I've let them run down below 0.9 V per cell.
As Empath noted, the rechargeable alkalines don't refresh well from this low a charge, so I try to avoid going that low.

My emergency, infrequent useage, outdoor lights are typically lithium AA's and my indoor stashed around the house emergency lights are usually alkaline AA's.

I don't own a single alkaline D cell and I use alkaline C's only in my infrequently used Pelican Super Sabrelight.

Many of my maximum brightness per weight/volume toys and tools have CR123's in them. They are frequently used for relatively short run times.

I also have battery user-upper lights. 3 lights have JBechtoe 4.5-4.8V 4 LED clusters driven by 4 alkaline AA's run down to an average of 1.2V or less. My X5 and X5T finish CR123's at the moment, but I suspect that they will be challenged in this role by my 9P with a KL3.

MSaxatilus, as many have noted if you are using a device a lot or it goes through batteries a lot you will really like the newer NiMH cells. I would however get a good charger, it can make all the difference. I am now using the MAHA 401 and really like it, but the Rayovac 1-hour unit has got some good marks.

With my digital camera (Minolta D7) you get about 20 shots if your lucky with alkaline and I regularly get over 100 using even 1600mA Ni-MH's.

I personally like http://www.durashop.com/ for batteries and chargers, but again any good charger mentioned above and at least 1600mA will work.

I also stick with lithium AA's or alkaline in low drain devices or not often used devices, just so I don't have to charge them every other month.

Your decision will probably be based on the drain rate of your application--that is, how much current it uses. This figure is very low for remote controls and large for power tools.

Alkaline cells have a steep curve when you plot runtime vs drain current. They like lower drains and die quickly at high drains.

NiMH (and NiCd) have a much higer tolerance for high drain applications than do alkalines.

This is moderated, somewhat, by alkalines having a higher total capacity. An alkaline will typically be a little over 3 Ah which top of the line NiMH cells are just starting to push 2Ah. The trade off in lifetime between good cells of both types is probably around 100ma of drain--typically that's more than a CD player uses and less than a GPS.

So, the breakdown typically goes:
NiMH wins for:
Powertools
large flashlights
Radios that transmit (tranceivers)
medium flashlights
GPS
small flashlights (heavy use)
Alkaline wins for:
CD players
Radios that only receive (they may be able to transmit, but if you're just listening, that doesn't matter)
small slashlights (normal to light use)
Remote controls (IR type for consumer electronics)

So, stick to alkaline for the latter group and use NiMH for the former group.

Now, comes the Lithium AA cells. You can think of these as single use NiMH cells--as far as their current load properties go. They also have the aditional benefit--above and beyond both NiMH and alkaline--of having very good extreme temperature performance. Basically, if it gets near or below freezing, Li-Fe cells are your friends. Oh, they also self discharge slowest of all AA chemestries, so they're favored for emergency (it must work) kind of use.

I hope I didn't leave anything out.

Some Target stores have Rayovac NiMh 4-packs for $9.99 That's the best price for 1800 cells locally.

- Vikas

The older CD players use a lot of power(a pair of 600mah Ni-Cds is used up in 2 hours; 300ma).
The newer ones probably use less power.

I can attest to NiMh use in digital cameras. No compareson to alkaline or NiCads. TX

Originally posted by star882:
The older CD players use a lot of power(a pair of 600mah Ni-Cds is used up in 2 hours

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<font size="2" face="Verdana, Arial">Yeah, I remember those...not much fun, though the only option so I used them a lot anyway.

I have a Panasonic SL CT-470 2 AAA CD player now that I ran through several CDs and then went to recharge its 650mAh NiMH cells...well, they were hardly drained. wow.

AA alkaline batteries are rated at about 2800 maH with a 30 ma load (50 ohm per cell). At higher loads the rating drops almost in half(1500 @ 500 ma). NiMH batteries have a much better load capability, an 1800 mAh batt discharged at 100 ma would give 1800 mAh and at 500 ma, >1700 mAh, at 1800 ma 1600 mAh. Not quite linear but for practical purposes flat. above 2500 ma the curve drops due to self heating.

If you have a light load and light useage Alki's are ok but if you are going after the latest and greatest NiMH is it. For that must work when I really need it after it has sat around in the glove compartment for months, then Lithium is the only answer

NiCads are generally considered obsolete as you can find MiMH batteries with twice the mAh rating for >150% of the cost.

Some pretty graphs at:

http://www.duracell.com/oem/Primary/Alkaline/alkaline_manganese_data.asp

http://www.duracell.com/oem/Rechargeable/Nickel/nickel_metal_tech.asp

But of course for high power consumption devices, they still use NiCads... Just look at the MaxaBeam for example. They use multiple F size cells for their battery packs.. all NiCads... Higher voltage under large current draw.... more resistant to being over-drained... or overcharge...

Nerd:

To my knowledge, the only NiMH's designed for high current applications are the R/C Sub C cells that put out at least 1.1 V per cell for most of their capacity under a 20Amp drain.

Other premium NiMH batteries show curves suggesting that drains of 0.5C will not drop below 1.1 V output for most of the capacity. A drain of 1.3 C will often drop voltage to the neighborhood of 0.9V.

Flashlight OEM's also are inclined to use NiCads which are more difficult to destroy when left on extended trickle charges. Effective NiMH chargers are too expensive for most OEM's.

Flashlight OEM's also seem to be sensitive to the more rapid self discharge characteristics of NiMHs.

I pushed my GP1600 mah batts pretty hard the previous time... talking about 5 amp loads.... for around 3 mins.... the plastic wrap melted... the chemical leaked.... yuck..... when I pop in some Sanyo 1000 mah ni-cds for the same device... it went through everything more quicker......must be internal resistance

Guess it's a matter of how manufacturers control their products... nimhs specialized for high drain appliances don't have high capacity.... can't have best of both worlds... sad..

Well, compared to the old days:

1. Chargers are much better. Inexpensive, high quality Rayovac and Eveready chargers for NiMH's won't kill the battereies, the way almost all old nicad chargers would. The old chargers were 'dumb', and if the batteries were left in them, they'd wreck the batteries. The main reason batteries die is bad charging, and that was the rule rather than the exception in the old days.

2. NiMH's have a capacity close to that of Alkaline. Used to be, Nicad's were less than half, and the figure went down as they were damaged by charging.

3. Shelf life of NiMH's sucks. Figure 2 weeks without charge and you've lost half your capacity, depending on the battery. (2 days for surefire )

My experience with NiMH usually agrees with everyone else's but I've recently been amazed to find that the 4 AAAs in my Cobra FRS radios are still showing full charge, even though I used them continuously for a weekend, over a month ago, and haven't charged them since. Used them again for an hour just two nights ago, and they still showed full charge after that. Weird...

FWIW-I just checked my 4-AA GP (1100 mAh) Nimh -after not being charged for 4 months, and they still showed about a 60% charge..
So I operated one of my 500mA lights and the light stayed on for about 55 minutes before quitting.