Can batterys afect depth

[urge]

On an other forum, they are discussing getting etxtra depth out of a higher rated ah battery (2,900)

all being quel, (sensitivity setting the same) how can amp hours make a differance????

[Sean_Goddard]

UKDN perchance?? Because they have NO idea what they are talking about AT ALL there!!

But the answer is YES, on a PI where inability to draw sufficient current to reach peak power and thus magnetic field will cause depth loss, so unless you are running off a PP3 (9V battery) or AAA's then you shouldn't have problems. A 12V Pb Gel battery would give great results as the peak current can be 50A+.

On a VLF is may make a slight difference, but not so much that you would notice unless you are using a VERY high power Tx, and that would be very unlikely.

Generally though, there are FAR too many people spouting this sort of rubbish with regards to metal detectors, it just goes to show how many "know it alls" are involved in the hobby. SADLY most of them are dealers from my experience!

[KingJL]

On an other forum, they are discussing getting etxtra depth out of a higher rated ah battery (2,900)

all being quel, (sensitivity setting the same) how can amp hours make a differance????

I do not know the context of the discussion, but battery capacity can affect effective voltage/current. Some (not all) higher capacity (mah) have a lower internal resitance resulting in the capability of higher voltage/current under load due to lower loses.

Regards,
J. L. King

[urge]

To put it simple.

If you had a common detector, say a whites, working off 8 aa batterys. duracells or any aa battery for that matter.

with the detector sensitivity set at say 12 oclock.

now change the batterys to say a 2,900ah battery, still a aa. would you gain any depth. full stop

[Max]

To put it simple.

If you had a common detector, say a whites, working off 8 aa batterys. duracells or any aa battery for that matter.

with the detector sensitivity set at say 12 oclock.

now change the batterys to say a 2,900ah battery, still a aa. would you gain any depth. full stop

Hi,
I don't know exactly what are you looking for... but I can say that battery status could change a lot of things , expecially if your target detector is somehow driven into instability due to lack of power from supply source , and this happens quite frequently with common vlf detectors (and also PI for that matter).

Some older models were powered by much higher voltage source cause of drop of batteries during use , though an ad-hoc regulator employed, will lead to instability.

In more recent times you see rechargable battery packs like you wrote and then with most of them things are easy, also you have to consider that devices today are more efficient than some decades ago.

But, generally speaking, the battery status and battery drop rate curve is REALLY important in MD applications... any serious THr know this very well... that's why is always good idea having a ready charged battery pack handy to replace if needed.

You will notice that any detector that has a loud speaker/piezo will get you into troubles with not rock solid battery power... will drift , will give you false signals more often than with perfect state battery, will give you all the instability it can produce from weak power source.

In impulsive kind of TX, having more charge (so more peak current available) have direct implications on depth: more current at coil during tx phase, more the magnetic field strenght , more the SNR , more the depth on buried stuff. Plain logic.

Kind regards,
Max

[urge]

I thought my question was simple

if a set of AA batterys are new, or as in the case of recharables, fully charged, can one make give extra detph over an other (fully charged or new) batterys.

simple.

dont complecate it.

so for a detector needing 4 batterys, it has four fully charged or new batterys, if it needs 8 it has eight etc etc.

none are discharged or faulty or low in power.

Not interested in how long they will last, just if one make of batterys will make the detector work deeper when batterys are new.

Some one claims that they are getting extra depth simply because they have changed from dry cells (good quality) to extra high strengh 2900ah batterys.

I dont think it makes any differance

[gef12]

I AM THINKING YOU HAVE A VLF MACHINE
AS IN MOST MACHINES HAVE SOME SORT OF VOLTAGE REGULATION I THINK IT WOULD NOT MAKE AS MUCH DIFFERENCE.
IT MAY HAVE A SUEDO AFFECT ON THEIR MINDS ... "OH MORE BATTERY POWER I AM GETTING BETTER DEPTH".
IF THE BATTERIES ARE NEW AND FRESH YOUR DETECTOR PERFORMANCE WOULD BE 100 PERCENT BUT AS IN THE CASE THAT THEY START TO DIE OVER TIME WHEN IN USE THEIR PERFORMANCE DETERIORATES ..THEY CAN NOT KEEP UP WITH REGULATOR INPUT. BUT IF YOU HAVE A HIGHER CAPACITY BATTERY BANK THEN THEY WOULD DEFFINATLY LAST LONGER AT 100 PERCENT
HOPE THIS EXPLAINS.

[michael]

Hi, I think Max told all things, then what are you looking for?
there is one simple thing: the more amperes(capacity) the more lasting time.
then the more stability. with using other kind of batteries nothing will change. when you have your essential voltage you can use in 500 mA or even 100 Amp no difference. but with 100 Amp your detector will work stably so much longer.

of course the battery generation differs; in rechargeables SLA (sealed Acid) are much more better than NiCd, NiMh (Nickle Metal hydrate) better than SLA and LP(Lithium Polymeres) better than others. as from SLA to LP capacity rises and size decreases.
for your stability and keeping your MD power need full original voltage that your device uses. simple.

with using full voltage and Amps you only keep your MD in optimum capability and stability nothing more.
e.g. in one of my PIs which works with 18 v-1.3 Amp internal, when voltage drops to 17 v we immediately use external feeding (4.5 Amp) with external battery we work for hours without any disturbance.
in 17 v its' depth drops somehow and in 16 V becomes somehow unstable and gives false signals.

[Max]

I thought my question was simple

if a set of AA batterys are new, or as in the case of recharables, fully charged, can one make give extra detph over an other (fully charged or new) batterys.

simple.

dont complecate it.

so for a detector needing 4 batterys, it has four fully charged or new batterys, if it needs 8 it has eight etc etc.

none are discharged or faulty or low in power.

Not interested in how long they will last, just if one make of batterys will make the detector work deeper when batterys are new.

Some one claims that they are getting extra depth simply because they have changed from dry cells (good quality) to extra high strengh 2900ah batterys.

I dont think it makes any differance

Hi,
I told you already but maybe you didn't undestand me in previous post.

I don't complicate things: they are complicate.

I repeat it again using some examples. Ok , you have e.g. 4 batteries , but which kind ? dry cells ? zinc-carbon ? alkaline ? lithium ? or rechargable pack of e.g. NiMh or NiCd or SLA or gel-type or mercury or whatever ?

Why I ask you that ? Simple: each has different voltage per cell and different capacity rate per weight/size.

I wanna simplify our discussion then I will assume you are talking of dry cells , alkaline kind like AA duracell or energizer and 2900mha NiMh cells only.

Ok, let assume you need 12V, an 8V regulator inside your MD with 3volts dropout, 50ma average consumption of electronics and use the duracell stuff (AA / LR6) : actually you will have 1.5V nominal per cell, so multiply by 8 you got exactly 12V, minus 3volts of dropout and you will get 1V more than lower bound limit at input of regulator: that is, you will get your 8V inside detector with no danger of losing voltage on supply rail till your cells have a drop of 1/12= 0.083333333... volts each.

You can be sure that using this approach your detector that has an average current requirement of 50ma will last long and happy during your TH trip. Many hours... probably more than 8hours with no problems at all. Note that AA by duracell (fresh , brand-new, model "duracell-15A") are rated 2100mah with nominal 1.5v per cell.

OK knowing that you know you will have, ideally, 2100/50 = 42 hours energy ... BUT... AA alkaline cells have drop during discharge... and you cannot stay happy if your cells start to drop more than 0.08V each (about 80mV drop in our case)... so REALLY you will have something say 15-20hours really you can use them on device with no pain. Also, you must consider that each time something alerts you...more current is consumed there... and battery will last less time. So , say you will be happy for 8-10hours with duracell there and detector will run really cool/smooth in that interval of time.

NOW, suppose same detector, same stuff BUT NiMh batteries with nominal voltage at full charge of 1.2V and capacity of 2900mah.

OK, you'll get just 1.2 x 8 = 9.6V instead of 12V of above... but cells retain more charge/capacity so can last longer at same current rate discharge.

BUT MAN YOU HAVE 9.6V THIS TIME! AND YOUR REGULATOR HAS 3V DROP THERE...INSIDE MD... HOW THE HELL COULD IT WORK COOL THEN ?
Actually it will be totally unstable stuff... no matter of capacity... drop-out will make your life totally hard with that batteries on that MD!
You will not reach 8V internally... but maybe 6.7-6.8V and then your device will stay very HOT... very unstable and totally useless.

This is a clear example of how batteries can make your life worse... if you wanna just replace 4 x 4 cells or 8 x 8 without taking care about details.

What about if you use 10 NiMh instead of just 8 ? Things will radically change if so: you'll get again 1.2x10=12V and detector will stay happy, and this time for a longer run, cause you have 2900mah instead of 2100mah this time.

Same, with just 8 NiMh if your regulator instead of 3V dropout has just 1V: it will work just fine with 9.6V input voltage.

As you can see from the examples of above... are not only batteries that make the difference but how you use them: you cannot replace 1.5V cells for 1.2 ones always with same results cause much depends on electronics inside the MD box...

Returning to the impulsive TX stuff... you will gain power if can get more impulsive current drain from source batteries... SURE IT IS, THAT'S WHY PI ALWAYS USE HUGE BATTERIES (look at Eric Foster's designs... some run with average current of 0.5Ampere and several amps at each tx pulse).

So... the answer to your question we cannot give you if you don't know details of what are you doing...

If your friend told you that MD works better on a particular kind of batteries that's so cause electronics could take advantages from that change, just this. But understanding why is matter for those who watch stuff inside the box... not just battery blisters.

Hope you now understand this topic better than before.

Kind regards,
Max

[Sean_Goddard]

I think the simple answer is, that the INTERNAL resistance of the cell CAN have an effect, but on the whole, the manufacturers design their machine with this taken into account by their "recommended battery".

"Upping" the capacity from what the manufacturer recommends (assuming they knew what they were doing in the first place, and most would on a simple aspect of design such as this), then your answer is.....NO, any percieved depth gain is just that.

Google "Emperors new clothes" for an explanation of what I mean by this, and you will see a truism that applies to this like no other hobby I have ever been involved with (so much mis-information and pseudo-scientific terms it's laughable at times).

[Max]

I think the simple answer is, that the INTERNAL resistance of the cell CAN have an effect, but on the whole, the manufacturers design their machine with this taken into account by their "recommended battery".

"Upping" the capacity from what the manufacturer recommends (assuming they knew what they were doing in the first place, and most would on a simple aspect of design such as this), then your answer is.....NO, any percieved depth gain is just that.

Google "Emperors new clothes" for an explanation of what I mean by this, and you will see a truism that applies to this like no other hobby I have ever been involved with (so much mis-information and pseudo-scientific terms it's laughable at times).

Hi,
totally agree. Common people often look at battery blisters more than at what they have to look with care and serious attention... sure internal resistance is another good issue, expecially in the long run , but these are topics for refinite minds... not for blister examiners, I mean...

I think our unregistered friend will not understand this concept... and probably also all the others...

The misleading informations about MDs are something that always make me laugh much when realize what's the purpose of some ads direct to customers... sure the marketing guys are smart (not really... but lets assume they are...) enough to find new ways of selling the same 30years old technology using some good slogan, some lcd and led... and similar crap.

The fact is that confused minds are the best places where to sell stuff even defective... and that guys knows (at least this) very well... so nobody of them will never talk about real performances and facts but just pushing this or that trendy looking detail...also cause marketing guys have really no idea of what's inside an MD.

If people really understand what's inside their thousands dollars MDs probably half the world market of MDs will vanish like kinda of a fog... in a few days.

Kind regards,
Max

[ivconic]

Question is right. Mostly depends of design itself. Poor design without reagulation&stabilisation cicuitry will suffer from certain drifts in TX amplitude and possibly even frequency. Good designs will work in a "straight line" as long as battery exceed calculated limits.
Tesoro Golden Sabre has FET oriented amplitude stabilisation, also 7808 regulator.
Fisher CZ5,1265 and many others do have pretty interesting power supply regulation (see schematics).
Whites (older) have 78s40 oriented convertor with good stabilisation.
So...battery condition will or will not affect overall performances...but this depends mostly on md design,itself.
All other stories are just justifying mentioned above.
Since i dont like to much "philosophy", i am simply using 12V/1.3Ah accu with all my handmades, so far. Enough power,no drifts,unlimited recharging etc.etc....

Refering TGS; power drains at it is 40mA (silent) and 60mA (loud sound)....so; as long as battery supplies 11v (7808+3V(drop)) and at least 65mA...device will work in a "stright line"....
Simply as that!
Cheers!

[urge]

Hi And thanks for the complecated reply

I am not un-registered. I just forgot to sign in

In my feild of work (carpets and floors) I am very knowegable, even though Dyslexic.

I have not rushed out and bought new batterys, just because of claims (I know you never said I did)

But Why should I become an expert just to get the truth????

Thats why I am here, only ever posted a few questions, and am learing all the time.
we all start some were, some are more into it than others.

I have tried to ask a simple question, but maybe a link to the forum will expain what I mean

http://www.forumukdetectornet.co.uk/...p?f=37&t=77342

Yes a lot of them dont know what they are on about, BUT THEY do deserve to know, just because they aint studyied as much as you lot.

they are still people how DONT NEED to waist there money on what dont work.

So Please a simple yes or no to these batters making a differance

[Sean_Goddard]

Urge, sorry if I, or anyone else here insulted you, I can assure you, it was NOT intentional.

You must understand that the maketing of MD's is full of lies and made-up terms to sell, as Max says, 30 year old technology. I give you Tesoro!! I have NOTHING against them, GREAT machines, but they have NOT brought out a truly NEW design since the Silver Sabre.

I appreciate you know more about flooring than I do (GOOD on you) That's what YOU do, Electronics is what WE do , and dispelling the myths is ONE of the things we do best. As stated, it IS a complex subject, but NOT in the context that the average MD layman would understand the subtleties of the answers given (if that makes any sense).

Yes, I agree they DO need help, but I am not qualifed to give the kind of help THEY need, and to be honest having been booted off that forum FOUR TIMES for contradicting the LOSERS who are admin on previous technical points I REFUSE to help ANYONE who is connected with that forum (SORRY, nothing personal).

I'm not sure how to say differently what has already been written. What machine are they talking about please, and what batteries are they CURRENTLY using and do they PROPOSE? Tell us that we can say Y or N definately.

[Max]

Hi And thanks for the complecated reply

I am not un-registered. I just forgot to sign in

In my feild of work (carpets and floors) I am very knowegable, even though Dyslexic.

I have not rushed out and bought new batterys, just because of claims (I know you never said I did)

But Why should I become an expert just to get the truth????

Thats why I am here, only ever posted a few questions, and am learing all the time.
we all start some were, some are more into it than others.

I have tried to ask a simple question, but maybe a link to the forum will expain what I mean

http://www.forumukdetectornet.co.uk/...p?f=37&t=77342

Yes a lot of them dont know what they are on about, BUT THEY do deserve to know, just because they aint studyied as much as you lot.

they are still people how DONT NEED to waist there money on what dont work.

So Please a simple yes or no to these batters making a differance

Hi,
as Sean and Ivconic already wrote above... we cannot say Y or N in aswer to your question without knowing all the details required. Details MAKE the difference between an Y and an N about this topic of batteries and depth.

So, if you tell us you are using e.g. a Tesoro BandidoII and a pack of AA batteries on it and wanna know about NiMh advantages (if any) we'll sure answer your question with an Y or an N , and as well a good, detailed explaination of why it's Y or N.

Simple as that: you know scenario and you will know or predict behaviour; you don't know or cannot focus enough and any answer will be pure speculation.

Now... cause we are addicted to electronics and MD at very serious level (at least of interest, someone also cause of work issues) we cannot take part in speculations here like in other forums is often made by people having low understanding of what's inside the "box".

I have nothing against you... and also the thread could be interesting BUT only having real data to work on.

Any generic question about e.g. batteries and MDs or anything here, so without required details involved, is like asking "the sex of angels"... so anyone could write anything without any real meaning in the real world.

That's about like talking about philosophy maybe or theology...I don't know... but sure IS NOT electronics....and cause I'm not a bishop...

Ask us the electronic way and you will get all the answers you need.

Kind regards,
Max