Dry cell batteries

[Guest 000]

Nothing at all to do with boats.

 

What is the story with dry cell batteries? I have a few things on board and at home that use AA batteries so I thought to get some rechargeables to save a few dollars. I figured the Eveready lithium ones with an Eveready charger would be a good bet.

But,they are pretty pathetic.

A disposable AA will give 1.53 to 1.55 volts when new but I can't get the rechargeables to load up any more than 1.48 volts. It powers my wall clock at home for about 8 hours whereas the disposables last for months.

Is this normal with rechargeables?

[Battleship 100]

You probably dont want to hear, but I tried the rechargeable thing for a while but relented and go with the 40 pack from Bunnings now, about the same cost but way more convenient.

If they go flat no scrambling for a charger just grab another set, not very green mind you.

[Clipper 346]

Yes, they are usually 1.2(?), not 1.5?

 

I use rechargeable AA batteries in my 2 speed pucks and my handheld GPS and get what I think is pretty amazing life from them. I bought a stack of 'Powerex' NiMH batteries and thought they were so good I bought more. These are 2700mAh, the capacity is different among different batteries too.

[Clipper 346]

I've found there is no comparison between the big packs of rubbish batteries and decent rechargeables. I bought enough to always have a full spare set for every device, think only time I needed to swap was doing a 30 hour race.

[Clipper 346]

I got mine here, but don't recall them being that expensive!

 

http://www.recharged.co.nz

[Battleship 100]

They look pretty expensive to me.

For sailing more than a few days the big pack works best for me. Don't have to mess with chargers.

That said most devices I have are lithium Iron these days the AA and AAA's are mainly for back up and things like strobes. Where rechargeable are not much good as they slowly go flat whether they are used or not.  

[Guest 000]

Just checked the Eveready rechargeables. They are only 2450mA, not 2700mA. That's probably where I went wrong.

[Island Time 1,252]

ma-hrs is capacity,not voltage. Rechargeables are usually 1.2 volts rather than 1.5 in the disposable. Some devices are ok with that, some are not. By far the best life will be a disposable of good quality

[Clipper 346]

the AA and AAA's are mainly for back up and things like strobes. Where rechargeable are not much good as they slowly go flat whether they are used or not.

Agreed. I always make sure mine are charged just before a race, rather than after a race. My emergency gear (torches and strobes, handheld GPD do not have rechargeables.

 

But for often used devices, they are great.

[Black Panther 1,607]

When you say devices, what are you talking about??

[waikiore 410]

Used to use them in my Electron, but life was pathetic so just bought quality batteries and enjoyed the major difference 6-8 times the life. Compared to the cost of the grog we drank at Orakei Basin batteries were minor

[too_tall 15]

I have been using NiMH rechargables for many many years now. I never bothered with NiCd as they were of insufficient capacity.

 

What IT says about the voltage is true, however, and 1.2V is sometimes insufficient for particular devices. That being said, the NiMH sag far less than most cheaper dry cells under load.

 

I have a couple of Led Lenser lights which do not operate at all well with NiMH batteries, but are brilliant with Duracel or Energizer alkalines batteries.

[too_tall 15]

I've been using Eneloop Pro rechargeable for a while and found them great, by far the best I've ever had and I've tried a fair few. Hold charge very well when in storage and being hi capacity run for a long time. Charge them using a Watts Clever charger, slow but packs them chocker each time. Only 1.2V but never had any issues in the gear I use them in, most of which are multi battery applications i.e. 4 or more at a time.

 

That charger says it can recharge std batteries as well. Only a few times before the just won't again, up to 10 according to the paperwork. I tried some once, outside away from anything in case it went bad, and it seems the paperwork is right. Did 4 AA std Eveready Energiser, the silver ones, and they worked like new... and for about the same time frame I think. Haven't done it again since though.

I think that most of my batteries are either Enerloops, powerhaus or camelions. The first two are FAR better than the last one... I might have the same charger as you do KM, but I have never been brave enough to recharge a non rechargable.

 

I believe it wont be long before people start using LiIon batteries almost exclusively. The energy density of those vrs a NiMH are significantly better. My Led Lenser H14.2r has a pair of 18650's in it and they burn a very long time. Compared to fitting 4 NiMH AA's ( I think its 4? Cant remember ) the burn time is about 10 times greater, and probably still about 3 times greater than high quality alkaline batteries. In fact, the 18650 LiIon batteries appear to last about twice as long per rated w/h as the Duracels, which is quite surprising, but might be related to the fact its operating in constant current, and will really hammer a battery which has voltage/current fall off as it discharges.

[ScottiE 174]

I did put the charger in the middle of the back yard under a box when I did it, I just had to know

Whew- and to hear someone else does that kind of sh*t!