Rechargeable battery life

[skookum]

High,
Now all sorts of tests have been posted regarding different detectors and/or coils as to their potential depth achievements.
I personally think, that an evaluation of the different brands of rechargable batteries would be of equal if not greater importance, because this factor is actually the main thing that keeps your detector alive, no matter which/what make of detector you own.
I did not mention alkalines on purpose, because their "green" footprint is not as good as with rechargables.
So who has the time and funds, besides being willing, to make an honest ( non-biased ) test in this regard ????

HH
skookum

 

[TerraDigger]

It really depends on the individual batteries. Same mfg...same type...lasted anywhere from 6 mo's to several years. Honestly, its kind of a crapshoot with longevity. For AA's my preference is Sanyo Eneloop low self discharge......for 9v...Powermax 9.6v 230 mAH low self discharge (need to use their charger as most other mfg's units cannot properly charge a 9.6v battery)

 

[Critterhunter]

Using rechargeables with a lower voltage won't reduce detector performance. Detectors have a voltage regulater in them that only allow a fixed voltage to the circuit board. All the extra voltage above that in linear regulators (which I'm betting all detectors use) is just bled off by wasting it as heat expelled to the heat sink on top of the chip. That's why people have to be careful using this lithium batteries that have a higher voltage than regular AAs. You may fry the regulator. Regulators do have a built in thermal overload so if you're lucky it will work again after it cools down.

There are switching regulators that are much more efficient and do not waste away the excess voltage as heat. Instead, they control the excess voltage by pulsing power off and on at a very high rate to the device. Only problem with those is they are bigger, more expensive, and generate a lot of noise because of the pulsing...So they require a lot of extra noise cancelling electronics. In a detector circuit board noise must be kept at a very minimum, so I doubt any detectors use them for that reason alone.

I've found that a good nimh 2500ma or higher in capacity will outlast a regular non-rechargeable battery in terms of run time. Amazing what these things can do these days compared to the first rechargeables on the market that didn't even get a fourth of the run time as a regular battery.

 

[Thound]

Theres already been plenty of tests and comparisons done.Just look on the internet. I don't remember the names of the sites but I do know that I settled on Energizer Recharge and have had good luck. Sony eneloop good but expensive.Make sure you get a smart charger. HH

 

[WoofWoof]

There are many sites that have battery comparisons but the easiest is Amazon. Just look up rechargeable batteries and read the reviews. I use Sony Eneloop but it's very important to have a good charger. The La Crosse Technology BC-700 Alpha Power Battery Charger is a great investment & will save money over the long term.

 

[Critterhunter]

Hobby City has a lot of cheap chargers and batteries. Best prices I've ever found on that sort of stuff. They are big in the RC crowd because they sell this stuff as well as RC parts really cheap. For instance, I can get a lipo battery pack from them for like $8 to $15 that other sites want $40 or $50 if not more for.

 

[sheetal]

Rechargeable batteries have lower cost of use and environmental impact than disposal batteries. rechargeable batteries have higher initial cost, but can be recharged very cheaply and used many times.

 

[slingshot]

I have found that smaller ma capacity batteries last exactly half as long as the alkaline. I used the Tenergy 8.6 v. in my Compadre and got 10+ hours. Also, the battery test function isn't reliable, as my detector just suddenly quit working.

 

[Digger 45]

Best battery out there for me is the Sanyo Eneloop low self discharge. I use them in the Sand Shark and have been getting 50 to 60 hours out of a set of eight, where the book says 10 to 20 hours with regular batteries. The nice thing is they hold their charge, other rechargeable battery seem to be half dead when you need them.

 

[Critterhunter]

Yes, it's always important to top off a nimh or nicad day or so before you plan to use it if you can't top it off the very day you plan to. They self-discharge sitting on the shelf, and so over say a few weeks or months they'll have lost a good bit of their charge. That's probably why some people think rechargeables don't last as long as regular batteries. They'll let them sit on the shelf for weeks after charging them and then think they don't give lon run time when they die early in the detector. In every device I can think of that I've used 2500ma or higher nimhs in I actually got more run time than a regular battery. Things like my digital camera as well as my detectors.

Probably why the Sovereign has 10 cells in the rechargeable pack, so that it will still have enough voltage to run the machine after sitting for weeks or months. These days I run a 3 cell lipo in my machine to save weight. Smaller. Lighter. Longer run times. Re-charges in one hour or less and that's not pushing a lipo like it is for nimhs.

Be careful with some of those nimhs that are supposed to have low shelf discharge. I've read some bad reviews where some didn't hold their charge as well as were claimed, as well as some not really having the capacity that was advertised. Same deal with this zinc rechargeables. People like them because of the higher voltage than nimhs but the ones I've seen the specs on don't have nearly the cycle life of a good quality nimh. Also, there are nimhs said to be built for fast charge times. All the ones I've seen the specs on of those also have had much shorter cycle life spans than regular nimhs. Regular nimhs can be fast charged in an hour or less, it's just that it shortens their life spans. That makes me suspicious that the fast charge nimhs might mostly just be regular nimhs that they advertise as fast charging ones that they throw in with a fast charger. I haven't kept up on these details for a couple of years since I'm a lipo guy for the most part these days, so some of these things may have changed by now.

 

[TerraDigger]

I read about all of the rechargeable tests worth salt one can find on the Net...read hundreds of user reviews....and went with the Sanyo Eneloops for AA batteries. They just have the best performance/longevity (dependability) record. No problems with the eight of them I use.