Which batteries for 2 cell incan?

[Leo]

Hi,

I'm using 2 AAA Uniross Hybrio low self discharge Ni-MH batteries (800mAh) on a PT Blast (a small 2 side by side AAA incan flashlight). This light is my EDC, and use it once in a while. After some usage the light will go from fairly bright to almost zero in seconds, with no prior warning. Thankfully this has happened at home, so it was a simple matter of replacing the batteries (and this already happened twice).

These batteries were fairly expensive, and I use them carefully, charging them with a standard Duracell Ni-MH charger (that takes 7 hours).

The empty cells read at 1.19 and 1.27 V, the full ones I've just replaced them with 1.35 and 1.34 V.

Which batteries do you recommend for infrequent usage for this flashlight? I'd like some advanced warning that the batteries are going to be depleted soon, because now they go from mostly bright to almost no light in seconds. Additionally, it feels like these batteries don't last as much as they should.

Thank you.

 

[wingnut86]

Alkalines would probably give you a declining output runtime, at least you would know when your light is going to die...

 

[mdocod]

Sounds like a combination of factors may be at work here:

1. The Hybrio cells aren't as "low-self-discharge" as one would hope them to be and you are loosing a lot of stored energy to self discharge.

2. The Hyrbio cells don't have the capacity that is claimed, perhaps far less, resulting in less than expected runtime.

3. NIMH cells naturally have a very sudden decline when they are depleted. So it's normal to see a very sudden dimming occur when you come up on the end of the available capacity, as it would turn out, this is a characteristic of MOST "good" chemistry types. Funny thing, if you want a gradual decline in output, you would want to revert back to what most would consider to be less desirable cell chemistry, like alkaline.

Some combination of the above is probably occurring here.

My suggestion would first be to get a good smart charger that could give you an idea of how the cells are performing. The problem with this suggestion, is that the charger will probably cost more than the cells, the flashlight, and your current charger combined, which begs the question, why bother. So if you have another use for a quality charger that is the direction that might be worth heading in.

Eric

 

[Mr Happy]

Some Uniross Hybrios are identical to Eneloops (I have a bunch of them). However it is hard to tell without a few close-up photos. (Eneloops are the best of the best.)

Fully charged cells should come off the charger at 1.45 V or more. Even charged cells that have been off the charger for a while should be 1.38 V or higher. A charged cell reading 1.35 V is a dead/damaged/crap cell (see next point).

When you run a light that uses two, three or more cells, you must (must must must) remove the cells for recharging before the light shows any noticeable dimming. Running NiMH in a two cell light until the bulb dims is the surest way to destroy your cells. Don't do that. Really.

Lastly you might need a better charger. Good chargers charge in 5 hours or less (it's too complicated to go into the reasons why). Duracell mostly makes good chargers, but you should avoid buying the bottom of the range models of any brand. Look for one that can charge 1, 2, 3 or 4 cells, and that takes from 1 - 5 hours to charge. If the charging current is shown it should be 300 mA or greater for AAA cells, 500 mA or greater for AA cells. (Higher is better, but avoid 15 minute chargers.)

 

[Leo]

Some Uniross Hybrios are identical to Eneloops (I have a bunch of them). However it is hard to tell without a few close-up photos. (Eneloops are the best of the best.)

Here are some pictures:

The bottom of the cells says: "Ni-MH - R03 / AAA / Micro - 800mAh - 1.2V Charging time: 7H-160mA"

Fully charged cells should come off the charger at 1.45 V or more. Even charged cells that have been off the charger for a while should be 1.38 V or higher. A charged cell reading 1.35 V is a dead/damaged/crap cell (see next point).

The cells had been charged some time ago (a month or two). I don't remember them reading that high off the charger ( but I don't usually check that).

When you run a light that uses two, three or more cells, you must (must must must) remove the cells for recharging before the light shows any noticeable dimming. Running NiMH in a two cell light until the bulb dims is the surest way to destroy your cells. Don't do that. Really.

Oops, I've done that a few times already.

Between this and all that mdocod said it seem to be a combination of not so great cells and poor usage from my part. I don't think I'll have the discipline required to check the cells and recharge them before the bulb dims, even with a smart charger. I haven't seen eneloops on stores here, but they would probably suffer the same fate as these ones so I think that I'll just use alkalines instead... I don't like this, but I would have spent less money and gotten a better service if I used alkaline batteries instead of the charger and NiMH batteries I bought.

Thank you for your informative replies.

 

[Mr Happy]

Here are some pictures:

OK, I don't think those particular cells are the Eneloop clones.

Oops, I've done that a few times already.

Don't feel too bad. I exaggerated a little there, but it doesn't do the cells any good and each time it happens the damage adds up.

Between this and all that mdocod said it seem to be a combination of not so great cells and poor usage from my part. I don't think I'll have the discipline required to check the cells and recharge them before the bulb dims, even with a smart charger. I haven't seen eneloops on stores here, but they would probably suffer the same fate as these ones so I think that I'll just use alkalines instead... I don't like this, but I would have spent less money and gotten a better service if I used alkaline batteries instead of the charger and NiMH batteries I bought.

I use rechargeable cells in lights. The bulb will start to get a bit yellow before it really dims and I just keep an eye out for that and put the batteries back on the charger as soon as I see it. If I know I will want to run the light for a while I will swap out the existing batteries for freshly charged ones.

Rechargeable batteries do work, but their different characteristics just take a bit of learning compared to alkalines.