Rechargeable Alkaline

[pobox1475]

The best piece of electronic gear I have seen are the rechargeable alkaline batteries from Rayovac. I have used them in D,C,AA and to a much lesser degree AAA. When fully toped off put out >1.5v and can be charged hundreds of times and thrive on frequent charging. The D's and C's have been used in portable satellite boom boxes for entire afternoon outings. I did however render a set of 6 D's nearly useless due to a parasitic drain in a radio as it drew power when switched off. I now take one cell out to break the circuit.

Positives:
1) High voltage output compared to NiCd & NiMH
2) Long life if used with care (see negative below)
3) Can be topped off so you know they are always ready to go

Negatives:
1) If allowed to completely discharge their usable life span is diminished (I use back up system and switch after 1/2 way usage)
2) Discontinued products and are harder to find. Similar cells marketed under GRANDCELL name that I have but not used enough to give an opinion.
3) Use specific charger technology, but will charge NiCd & NiMH as well.

 

[Mr Happy]

I have seen these cells -- Rayovac Renewal -- and their special charger in Fry's. However, they seem to have no advantage these days over the low self discharge variety of NiMH cell.

The Renewal cells are relatively expensive, have lower power output and poor voltage regulation like regular alkalines, need a special charger, take a long time to recharge, are only claimed to have a life of about 25 recharge cycles, and have their life reduced if they are fully discharged.

The low self discharge variety of NiMH cells like Eneloops cost only a little more, can be recharged up to 1000 times, can be charged quickly, have tremendous power output, have better voltage regulation, and also remain charged for months to a year or more.

I have often picked up and looked at the Renewals, but I just can't see an application where they would be a better choice.

 

[shadowjk]

Maybe they're good in some low drain but voltage sensitive applications... like, uh, certain cheap radios? As a bonus, if the device is very voltage sensitive and wont work with the 1.3-1.4V that a nimh gives you, you'll probably be recharging those alkalines way before they're empty, extending cycle life somewhat...

 

[Marduke]

You forgot the negatives of lower capacity and voltage sag under high load. This makes them not suitable for high drain devices.

 

[Lynx_Arc]

I had 4 AAA renewal cells back when NIMH were not available for sale and nicads chargers and nicads had memory issues. They are junk after about 25 uses because the capacity keeps declining and you don't realize it unless you are using them up quickly. I had them in a light I used up about once a month and over time it got to where every time I used it for 5 minutes it died. This light has a runtime of about 20 hours on new alkaline cells. Unless you must have that extra 0.1-0.25 volts to run things go with standard nimh for daily use and LSD for occasional use items. IMO you are better off skipping renewals and investing in NIMH + a few normal alkalines instead of throwing money at a charger cell combo.

 

[warlord]

If you're impressed by rechargeable alkaline cells maybe you should take a look at cells made with newer technology, Low Self-Discharge (LSD) cells.

 

[IMSabbel]

Maybe they're good in some low drain but voltage sensitive applications... like, uh, certain cheap radios? As a bonus, if the device is very voltage sensitive and wont work with the 1.3-1.4V that a nimh gives you, you'll probably be recharging those alkalines way before they're empty, extending cycle life somewhat...

Such a radio wouldnt work with alkalines either (leaving them 80% full).

 

[cave dave]

The rechargeable Alkalines are VERY prone to leaking. Even if unused. They often leaked in the package on the store shelfs. This can ruin your precious electronics. They also preform much worse than Nimh in flashlights. (they perform similar to partially used alks) I won't touch em again with a 10ft flashlight.


"In theory practice and theory are the same, but in practice they are not."

 

[pobox1475]

The rechargeable Alkalines are VERY prone to leaking. Even if unused.

Been using them for years without this issue. The recharge time is acceptable for me. I usually charge 3 D's in under 3 hours then let the other 3 charge over night. The radios used in (Sony, Audiovox & JVC) are far from a cheap classification and as stated operate utilizing FM, satellite or CD for up to 6 hours. They generally have cost me about 30% more than top shelf toss aways. The charger has been a good investment (have 2) and has given years of service and the versatility of being able to charge different types.

only claimed to have a life of about 25 recharge cycles, and have their life reduced if they are fully discharged.

True. But the 25 may be a little low, at least in my experiences. Even at 25 uses they are cost effective.

if the device is very voltage sensitive and wont work with the 1.3-1.4V that a nimh gives you, you'll probably be recharging those alkalines way before they're empty, extending cycle life somewhat...

This would explain my good experience. I generally don't let them run way down.

You forgot the negatives of lower capacity and voltage sag under high load. This makes them not suitable for high drain devices.

Don't have the to power anything higher draining than radios and voltage sag? Haven't or did not know I experienced it.

you should take a look at cells made with newer technology, Low Self-Discharge (LSD) cells.

I will. Eventually mine will need replacing even though I have plenty on hand now. They are good in some devices and not so good in others. It does take a little discipline to extract the most performance and longevity from them. This is a sacrifice I have been happy to live with. :twothumbs

 

[Robert15]

Everybody is on the NiMH LSD bandwagon these days. Rechargeable alkaline cells may still be better in one application, namely devices stored in a hot environment.

In my car flashlight in the summer, NiMH cells - even the LSD ones - would self-discharge due to the high temperature. I've used rechargeable alkalines in that light for years, and they stay charged for many months of non-use. (You do need to check for battery leakage with any stored light and catch any leakers early, but at least these cells don't discharge themselves.) The capacity of the rechargeable alkaline cells isn't great, but with an LED light the run time is still fine.

-- Robert

 

[Marduke]

Everybody is on the NiMH LSD bandwagon these days. Rechargeable alkaline cells may still be better in one application, namely devices stored in a hot environment.

In my car flashlight in the summer, NiMH cells - even the LSD ones - would self-discharge due to the high temperature. I've used rechargeable alkalines in that light for years, and they stay charged for many months of non-use. (You do need to check for battery leakage with any stored light and catch any leakers early, but at least these cells don't discharge themselves.) The capacity of the rechargeable alkaline cells isn't great, but with an LED light the run time is still fine.

-- Robert

Lithium primaries are king for flashlights in cars. They will not leak and are good for years. Any alkaline (primary or rechargable) will suffer greatly in any AA or AAA powered LED flashlight other than the 5mm style.

 

[Darkpower]

Gosh fellas, I see a lot of anti-RAM bigotry here.

I was an early adopter of the Ray-O-Vac RAMs (rechargeable alkaline manganese) 'Renewals' back in the mid to late 1990's and I still swear by them. I still have a quite a few of the Ray-O-Vacs and they all work. In fact, I had them fully charged in a junk drawer and rediscovered them last year and they were still holding their charge since the last time I moved house around 2001.

They have discontinued the "C" and "D" size, but the "AAA" and "AA" are still being made with improved chemistry by PureEnergy and Juice. I had never had one leaked unless it was charged in the wrong charger. I use the Pure Energy XL "AA" and they have improved chemistry that can be recharged 500 times with shallow discharge (1.3 volts per cell or above) and about 50-100 times if its is a deep discharge (below 1.0 volt per cell).

But like some people pointed out their unequivocal advantage is the shelf life of their charge, which can exceed 5 years. Perfect for low drain Radios because many portable Radios need the full 1.5 volts and many quit after the battery reaches 1.3 volts. This makes many MiMh practically useless unless the cells come right off the charger. Secondly many Portable Radios will run for 200 hrs on a set of alkalines which if you use it for 2 to 3 hours a day, 5 days a week like I do to listen to radio talk shows in my office in the afternoon, a set of batteries of fresh primaries will last 3 to 4 months or even several years if you are a rare occasional listener. With the RAMs, I can top-off the Alkalines as often as I want and have fresh batteries in the radio without having to toss out primaries. It's like having your cake and eating it. :twothumbs

The Eneloops are no match for the self-discharge rate.

The disadvantage of course is the fact that like regular alkalines they don't have the high current drain of NiMh nor the life of 1000 cycles. I still use NiMh exclusively for everyday use flashlights and lanterns and for my emergency hurricane preparedness; I plan on rechargeable NiMh, RAMs and primary Alkalines as my workhorse source of lighting energy during power outage.

But the thing about the RAMs, is that they are a perfect niche for applications that are very low drainage or infrequently used flashlights and devices. I have flashlights in the garage for example that get used maybe for a minute or two, perhaps once a month. In that case, a NiMh would self-discharge more than actually be drained by actual usage. So a RAM is a perfect candidate because it will hold that charge for 5 years and not only that, but you can top off the charge at anytime. Say for example you really need to use that infrequent flashlight in the garage after a year or two…and you run it for 15 to 30 minutes, well with the RAM you can top it back off, and have it ready to go again just like a fresh primary alkaline, and it can then sit there for another 2 or 3 years. That makes it better than a Primary Lithium or Primary Alkaline, in my opinion, because even if you use a Lithium, if you use your occassional emergency flashlight once or twice for 20 to 30 minutes during the course of three or four years, you no longer have a fresh set of Primary Lithiums in there. They will now be partially depleted Primaries. I have an obsession thing about having fresh primaries (fully charged) in my Emergency flashlights. With the RAMs, it's the best of both world, you can occassionally use it, then top-off the charge and keep it there again for years to come knowing full well its is fully charged. It's like having your cake and eating it.

 

[warlord]

Beat me to it. Yeah, lithium would be the ideal choice.

I still use regular NiMH, LSD NiMH, lithium primaries, lithium rechargables, and alkaline primaries. My alkaline rechargables got recycled many years ago because simply stated, they just plain sucked. I have a hard time believing that anyone could be missing out by not using rechargable alkalines.

 

[Eugene]

I bought a bunch of renewals starting in the 90's, had up to three chargers even. I got tired of replacing the chargers every few years as they were cheaply made and the batteries did only last around 25 top offs, which paid for themselves and if you had enough paid for the chargers too. but after one or two leaks and then difficulty finding replacement chargers and the new low self discharge holding their charge as long I gave up on them a couple years ago.
I found they needed a top off charge every 6 months to a year and Eneloops are doing just as well with the same 6 month to a year top off.

 

[aussiebob]

I bought a dozen or so alkaline rechargables a year or so ago and they were crap.
They had quater the runtime in same lights as good nimh and they stoped holding a charge after a week or two.

 

[lightforce2]

I bought 4 Grandcell RAM's a few years ago, they came with a charger that can also charge NIMH which was what I was really after.

Yes the RAM's still hold their charge after a couple of years of non use however the reason I'm not using them is because they have a very high amount of internal resistance that results in too much voltage drop under load, therefore defeating the benifit of the higher open voltage.

When it comes to rechargable AA's I intend staying with Eneloops. However the funny thing is I haven't thrown out the old RAM''s simply because I cant bring myself to throwing out a "full" battery that just maybe, maybe be of some unknown use some day

 

[LEDninja]

One more negative:
Rechargeable Alkalines leak, especially if they are more than 3 years old.

 

[lightforce2]

One more negative:
Rechargeable Alkalines leak, especially if they are more than 3 years old.

Thanks, perhaps I should get rid of them

 

[Eugene]

I didn't have too much leaking problems but it was because I topped them off once a quarter. Downside to that was I wore then out maintaining them.