Battery packs

[DirtAngler]

Does anyone use the rechargeable battery packs? Either the standard White's or the NiMH pack or do you just have a backup pack for the alkalines?

 

[norbyx]

I have the whites rechargable and they are quite good. I can make a 7 hour hunt without any problem. Now I also have a second pack (standard AA battery pack container) with some sanyo eneloop XX 2500 Mah rechargables. Those last forever.
Now I got all this batteries for my V3i mainly since the MXT is very conservative on batteries. But I use them on both obviously.

 

[Nancy-IL]

Personally I use the straight alkaline batteries. I think the rechargeable are heavier. Well, they are.....but not by much. I didn't think they held a good charge so they weren't in my machine very long. HH, Nancy

 

[Aarong81]

The rechargables will begin with less voltage and will not compare to the lifespan of Alkalines. There is another issue with the voltage difference but the forum has suffered enough debate about that, the lifespan difference is enough in itself to make up my mind but ONLY second to the 'other' reason.

I'd like to ask, does the rechargable packs have more cells in it than a standard 8 AA pack? I am only assuming it has 8 cells, therefor assuming it begins with less voltage than Alkalines.

 

[ga5150]

Ok, I'll bite. Could you point me to a link either here, or via PM so I can read up on this? I did a search for battery pack, rechargable batteries, etc; and didn't come up with much. I'm curious to learn about voltage debates.

Thanks,

Rodney

There is another issue with the voltage difference but the forum has suffered enough debate about that, the lifespan difference is enough in itself to make up my mind but ONLY second to the 'other' reason.

 

[Aarong81]

The debate is whether or not voltage below 10 volts causes chattering and loss of depth. I experience both when my MXT shows 10 volts or less, especially at 9 volts. The detector doesn't show 'Low Bat' until 8 volts so the average user would assume the battery is fine until it says otherwise. Heres one of the threads from awhile back, I'm sure there are others but the search only goes back 60 days or something like that. The thread started out about how fast the MXT consumes the batteries then begane comparing Alkalines with Rechargables, then into the voltage issue. Some say anything over 8 volts will perform the same as 12 volts. I can tell the difference just in the chattering alone when it increases with less voltage, the depth issue is a strong assumption since its hard to compare the one and only MXT you own with itself. Rechargables will get to 9 volts really quickly since they begin showing 10 volts which is higher than the math adds up to. Rechargables are 1.2 volts each X 8 = 9.6
http://www.findmall.com/read.php?25,1683286,1686984#msg-1686984

 

[gold_geologist2011]

I have a rechargable battery pack for sale if you would like it. I like the rechargable because it is cheaper in the long run. 8 batteries arent cheap these days...

 

[Critterhunter]

Many myths in this thread. First, nimh AAs weigh LESS than off the shelf non-recharge-ables. Second, 1.2V per cell for nimhs or nicads is MEANINGLESS , because even if a nimh has a lower starting voltage than an off the shelf regular battery, the truth is that a good high capacity nimh (or even nicad) cell will hold it's voltage higher throughout discharge than an off the shelf non-rechargeable. What that means is that at a certain point during the discharge of the pack, the nimh/nicad will have a higher voltage than a store bought non-rechargeable battery. A good high capacity nimh or nicad will "coast" across a discharge chart with yes...A lower starting voltage...But in fact somewhere during the drain they will maintain a higher voltage than a non-rechargeable during that drain. Now, that's somewhat reliant on the capacity of the cell. When shopping for nimhs shoot for at least 2500MA or higher in capacity. I've found nimhs that capacity or above actually will have LONGER run times than a good store bought non-rechargeable such as an Energizer (non-lithium typical cells...If you are going to buy non-rechargeables the lithium's are pricey, but worth it in savings due to longer run times and also they are a good bit lighter than a regular battery).

Finally, in terms of higher voltage giving you better performance or more depth. Again, a total falsehood. The fact is that modern detectors all use voltage regulators in order to stabilize "steady state" conditions of the circuit board. Meaning, they need a specific and constant voltage in order to perform within specifications. Further meaning...Doesn't matter what the voltage of the pack is so long as it's higher than the minimal input specs for the regulator. The output will still be say (for example) 9V, regardless of whether the pack is 10 volts or 12 volts. Now, there is a bit of a murky area in there, in which the amp draw of certain devices can cause the voltage to "sag" during peak power drain moments muddy the waters in terms of the current state of "charge" of a battery, but the reality is that in terms of metal detectors they are drawing WELL down into the milliamps in terms of amp draw. My machine averages about 50 milliamps of current draw at it's peak power demands. So minuscule that it's a non-issue when you are talking about the current delivering aspect of batteries...Rechargeable or not.

The fact is that even if the amp draw was overwhelming the battery and causing the voltage to sag temporarily, this would then trigger the LVC (low voltage cutoff) of the regulator, and so hence you'd then get a low voltage alarm from your machine. Sure, there is a fine line there when say the voltage could sag a bit while it's sounding off to the target, versus when it's not and thus the amp draw relaxes a bit and the voltage pops back up a hair. But that fine line, so unlikely due to the minuscule amp draw of a detector even when sounding off to a target (speaker output amp draw for instance)...And so unlikely due to the current delivering ability of AA batteries (rechargeable or not), even if it exists on machine X in situation Y...Is such a fine line to cross from total function to perhaps slight instability...That it's hardly anything to worry about, as you'd see the LVC sound off soon enough.

 

[Aarong81]

The weight is pretty simple and I didn't know of the myth. Alkaline AA batteries have a mass of roughly 23 g (0.81 oz), lithium AA batteries have a mass around 15 g (0.53 oz), and rechargeable NiMH batteries around 31 g (1.1 oz).

 

[Critterhunter]

I can tell you that my 2500ma Nimh AAs feel easily lighter when held in my hand as an 8 cell pack than 8AA non-rechargeables. For sure non-rechargeables that are even lighter are ones like the lithium Energizers. Those do cost more, but the longer run time easily makes up for the extra cost and the much reduced weight over regular AAs is a nice bonus. I'm pretty sure a while back I weighed my 8 AA nimhs, 8 regular AAs, along with my 3 cell lipo, just so I could post hard numbers on the weight savings of the lipo compared to the other two battery types. I'll see if I can dig that post up for you. If not, I'll weigh 8 2500ma nimhs and 8AAs and see where that stands to post.

Some people have the idea that nimh rechargeables are heavy due to the heavy stock rechargeable packs on some machines versus 8AAs in the regular alkaline holder. The fact is that some rechargeable packs can be made up of cells that are different than a standard AA (such as Sub-C cells), and so can be much heavier. Often these cells are designed for high amp draw applications (much higher than what is needed for the super low amp draw of metal detectors), and so are heavier and more robust then they need to be. A good example of this is Sub-A cells. Up until a few years ago they were the primary battery source for electric RC planes and cars, which can place high amp draw demands on them many times greater then you'd ever dream needed in metal detecting. My machine's stock rechargeable pack is using Sub-A nimhs and is a boat anchor that I never use.

 

[Critterhunter]

I started a thread on various rechargeable topics in the modifications forum. You can find it here...

http://www.findmall.com/read.php?22,1748161

 

[5900_XL-1]

I had an order of the XX Eneloops delivered here and intended to use then in the blue pack, but I read a general warning that they were thhicker and wouldn't fin in every application, so I refused delivery and returned mine, unopened. At 0.6" thickness per cell, I couldn't see any tolerence left to fit in 8, both width and height.

Did I make a mistake? Will the XX Eneloop batteries fit in the Whites blue pack? Thanks in advance. martin

I have the whites rechargable and they are quite good. I can make a 7 hour hunt without any problem. Now I also have a second pack (standard AA battery pack container) with some sanyo eneloop XX 2500 Mah rechargables. Those last forever.
Now I got all this batteries for my V3i mainly since the MXT is very conservative on batteries. But I use them on both obviously.

 

[Aarong81]

I had an order of the XX Eneloops delivered here and intended to use then in the blue pack, but I read a general warning that they were thhicker and wouldn't fin in every application, so I refused delivery and returned mine, unopened. At 0.6" thickness per cell, I couldn't see any tolerence left to fit in 8, both width and height.

Did I make a mistake? Will the XX Eneloop batteries fit in the Whites blue pack? Thanks in advance. martin

I have the whites rechargable and they are quite good. I can make a 7 hour hunt without any problem. Now I also have a second pack (standard AA battery pack container) with some sanyo eneloop XX 2500 Mah rechargables. Those last forever.
Now I got all this batteries for my V3i mainly since the MXT is very conservative on batteries. But I use them on both obviously.

Would the eneloop XX 2500 Mah be any different than any other AA rated at 2500 Mah? Seems that the capacity rating is spelled out pretty clear and should be equal. Whats the advantage to the eneloop XX?

 

[Critterhunter]

If the capacity is spelled 2500ma, 2500mah, or 2.500 amps (unlikely listed that way), it all equals the same thing. The higher the capacity the longer the run time. In modern AA nimhs I'd never buy any lower than 2500ma, and in fact would shoot for the highest capacity I could find at a reasonable price.

I've never really read up on the eneloops but I think they are just typical nimhs but claim low self-discharge on the shelf if I remember right.

Part of the reason why many claim they get low run times from nimhs or nicads is because they charge them and then let them sit on the shelf for weeks, which in turn causes them to self drain. There are various nimhs now with low self-discharge so they are still near full charge even months after charging.

You need to read up on those though because some low self-discharge nimhs don't hold up to their claims. I wouldn't mess with anything but low self-discharge nimhs these days in a detector unless you don't mind topping off a pack say every week or so between hunts to keep it ready to go. Some nimhs are worse than others at keeping their charge on the shelf, but the low self discharge ones (some of them anyway) are much better at holding the charge in storage.

I find 2500ma or higher AA nimhs give me longer run times than non-rechargeable AAs. Also, while a nimh may start out with a lower voltage than a non-rechargeable it will hold it's voltage higher longer, so sooner or later the non-rechargeable will be running at a lower voltage than the nimhs. Nimhs/nicads tend to flat line their voltage and hover near 1.2V for most of the discharge, where non-rechargeables will tend to drop their voltage more steadily as they drain.

I think those Enelopes are kind of pricey ain't they? If their main claim to fame is low self-discharge I'd check into the numerous other low-self discharge nimhs out these days. I think the enelopes were the first to make those claims, so I bet there are much cheaper options now a few years later. Just do your research and find out who's claims actually are true. Many independent guys who test batteries for fun in their free time who have some excellent research data on this stuff if you look around on the net.

 

[Delta Digger]

I had an order of the XX Eneloops delivered here and intended to use then in the blue pack, but I read a general warning that they were thhicker and wouldn't fin in every application, so I refused delivery and returned mine, unopened. At 0.6" thickness per cell, I couldn't see any tolerence left to fit in 8, both width and height.

Did I make a mistake? Will the XX Eneloop batteries fit in the Whites blue pack? Thanks in advance. martin

I have the whites rechargable and they are quite good. I can make a 7 hour hunt without any problem. Now I also have a second pack (standard AA battery pack container) with some sanyo eneloop XX 2500 Mah rechargables. Those last forever.
Now I got all this batteries for my V3i mainly since the MXT is very conservative on batteries. But I use them on both obviously.

Martin i use the Etrac eloops in my mxt and they fit perfectly inside the holder.

 

[Delta Digger]

I meant to say I use them in my mxt and they fit perfectly. The smart phone I'm on is not so smart.

 

[5900_XL-1]

Just to be absolutely certain we are both on the same page...you are saying that you use the Eneloop XX(the black ones) and they fit fine in the MXT battery pack? I assume the MXT and the V3i packs are identical. I really wanted to try the XX "big-boys" but couldn't chance being stuck with them if they didnt fit. martin

 

[Delta Digger]

I don't use the black ones. The white ones I use are 2000 Mah rechargables .

 

[grif]

I only use energizer ultimate lithium

 

[bigtim1973]

Well here is an answer to the 8 AA problem. You can go to youtube and type in 6 volt flashlight battery and take a look at how many AA batteries are in one 6 volt square flashlight battry..............................................36 of them!!!! Can you believe that? I did not until I found the video by chance one day. Take a look. That is what I am going to do from now on on batteries. Let me know your thoughts, Tim