Sovereign GT - rechargeable or alkaline batts

[looking4gold]

Hello all,

I'm a little confused about batteries for my Sovereign GT which just arrived today.

The source of this confusion is mainly a post I came across (not sure if it was this forum or another - but I can't find it now), where someone had modified a standard alkaline battery pack/holder so it could hold an extra two AA cells. The purpose of this was so he could use rechargeable NiMh batteries, since 10 x 1.2 V = 12 V.

The manual says nothing about using rechargeable NiMh batteries. It only mentions using "good quality" alkaline batteries.

I've tried using 8x 1.2 V NiMh batteries and the GT seems to work fine, but I was all set to modify the battery holder to hold 10 instead of 8 batteries. Since it works fine, I don't see the point now - or am I missing something? Is there a significant advantage to have an extra 2 batteries?

[Chef Geoff]

If you have the standard rechargeable pack with the machine you will probably find you won't use the AA pod. The Sovs can be a little temperamental with voltage (but strangely not all Sovs) in that they don't allow as much of a drop in power as the Explorers/Etrac. This could be because the Sovs have a preamp circuit in the coil which may draw more power.
I would give it a good test and see how many hours you are getting from 8 rechargeable batteries before doing anything drastic

[Val Beechey]

Treat yourself to 8 x 2000 Eneloop recharables. They don't suffer from memory probs and last almost forever. I use them in my Minelab Safari and get a goo 10 hours out of each charge.
You can buy a battery pod from Detecnicks for £21.00 post free and have a spare.

Val

[looking4gold]

Thanks for replies Geoff and Val.

I've already bought a bunch of NiMh rechargeables. I went for GP "ReCyko", which appears to be similar to Eneloop technology. The batteries are rated at 2050/2100 mAh, come fully charged, and claim to "last longer than alkalines" as well as to hold their charge when not used.

I've used standard GP NiMh batteries before, and they've served me well, so I thought these would be worth a shot. 18 x AA ReCyko cost me £28.95 including postage from flea bay, although I had to buy twice (from another online shop) since I neglected to allow for spares, so I now have (or will have when the last lot arrive) a total of 40!

On top of that I also got a Minelab NiMh 1000 mAh + charger (which I was not expecting!) together with the GT, so I can't see my partner or myself running out of power any time soon as long as the ReCykos are ok.

I actually bought a pack of Eneloops a few years back, but never formally tested them - they just went into my bag as backup spares (I'm a photographer with lots of bits of kit that take AA/AAA batts). I think I put a few of them in something a few weeks ago for the first time. I can't remember what though!

Anyway, I will see how I get on with the ReCykos and let the forum know.

[looking4gold]

I've left the Minelab NiMh battery pack recharging for 24 hrs now, and the green LED (which is supposed to fade/go off when the battery pack is fully charged) is still on. The manual says it should take between 12-14 hrs to fully charge, so I'm not sure what to do. Let it go for a bit longer and see if the green LED goes off?

[Chef Geoff]

LOL ummm some nicely cooked batteries you've got there
The light doesn't go out and the dimming is only slight so you may not even notice it. They go from flat to fully charged in 12 hours, So you've wasted 12 hours waiting for them, now get out there and find the gold

[looking4gold]

Ooops!

I wish the manual would have made that a bit more clear.

Thanks once again for the heads up Geoff.

I'm itching to get out there, but it'll probably have to wait till Monday at least now. Looks like my partner and I will be having to take turns on the GT thanks to the flea bay seller I mentioned in the other thread 

[Val Beechey]

You're not the only one to get caught out with that one. The way I tested mine was to pop it into the detector and look at the battery indicator.
Even when showing 3 stars it didn't seen to last very long as it's only the 1600. so I bought a spare Alkaline pod and some 2000 Eneloop batteries. I am so impressed with them I don't use the other one any more. As I said I get a good 10 hours out of them.

Val

[Chef Geoff]

Val your 1600 mAh should be lasting you well over a days detecting

[looking4gold]

Perhaps Val's 1600 mAh has developed a memory after not having been fully discharged before being recharged?

It's for that reason I like AA rechargeables and own a good quality recharging unit which has a "battery reconditioning" mode to revive batteries that have over the course of time developed a memory. It also has a "soft charging" mode that helps batteries live longer, although it takes longer for an empty battery to be fully charged.

[Val Beechey]

Geoff, that's why I don't use it and prefer the Eneloops. Do they suffer from this memory program thing ?? I know the Eneloops don't.

Looking4gold, sounds like you've got a charger similar to mine. It's one of Hubbies a Lipro Dual 6 that he had for his model aircraft batteries. I bought a tray (?) that takes 8 AA's and charge them all together. Even on a 0.5 amp charge it only takes a few hours. He used the excuse that I used it more than him to buy himself an even better one.

Val

[looking4gold]

Val, this is the charger I have:

http://www.mahaenergy.co.uk/products/battery-chargers/004-maha-c801d-8-cell-fast-charger

Quite expensive, but it's served me well over the years.

[Chef Geoff]

NiMH don't build up a memory, that's the older NiCad batteries.
There is no difference in active performance between Eneloop and any other NiMH battery, where they do score however is that they have a far lower "self discharge" rate, so if you charge them up and then put them away for a year, they would still have around 60% of their charge in them, normal NiMH batts will be flat after 6 months.
So if you detect regularly and always charge your kit the night before, save your money and buy normal but if you only go out once in a blue moon and on the spur of the moment then buy the Eneloop type 

[Val Beechey]

That looks like a stream line version of the one I've got. Much handier though. Still I wont look a gift horse in the mouth. It was volunteered (with an ulterior motive) and does a good job.

Geoff, I wonder if I was getting confused (again) . The NiMH pod seems to go to 1 star faster than the Eneloop. I've never pushed either to the limit though, I don't stay out long enough, usually about 3-4 hours, and always top-up after the second outing.
I know the Eneloops are s'posed to have a longer re-charge life as well as not suffering from the memory problem.

Val

[looking4gold]

I just came across this and thought if anyone is looking for cheap NiMh AA's, there is a good deal for eneloops here:

http://www.hotukdeals.com/deals/new-sanyo-eneloop-aa-x-16-pack-batteries-hr-16utga-rechargeable-up-1500-times-23-1510450

16 for £23.97 - but it is the old version (up to 1500 charges). Even so, I would have gladly taken advantage of this deal a week or two ago before I had bought my GP AAs!

The current version will take up to 1800 charges, and there is a new version that will take up to 2100 that should be here soon.

Apparently they are a little bit longer than most other AA's, so be warned that they may be a tight squeeze in some detectors.