Rechargeable NiMH and voltage concern

[DirtShoveller]

Hello,

I've searched around the net and couldn't seem to find a concrete answer to my concern for using NiMH batteries with the AT Pro (or any detector I suppose). I asked Garret whether or not the 4.8v from using NiMH batteries vs. 6v from using alkalines would at all impact the performance of the machine, specifically depth. This is the answer I received:

Hi ,


All of the current model detectors are equipped with voltage regulators which allow the unit to work effectively until the voltage falls off too low, therefore depth performance will not be affected. Rechargeable batteries can be used but we recommend alkaline batteries.

Let me know if you have additional questions.



Thank you

Sue Wilson

Customer Service/Tech Support

Garrett Metal Detectors

I don't feel this completely answers my question. I understand the AT Pro is equipped with a voltage regulator, but what type of regulator is it? I'm not well educated in the world of regulators, and reading their wikipedia page shows there are many types of regulators. Some can regulate at more than one voltage. I should reply back to Sue with this question, but I thought I'd ask you all first. If nothing else I'll set up a test garden using both alkaline and NiMH batteries.

 

[John-Edmonton]

I have been using rechargeable batteries in Garrett metal detectors for 20 years, and I have never noticey any difference with performance with alkalines vs. NiMH other then the NiMH will drop bars sooner then alkalines. I always changes batteries after 2 or 3 bars drop, because I don't know exactly where the voltage regulator is set, but it has always been below my 2-3 bars.

 

[WV62]

I was just reading through my AT manual and on pages 48 and 49 I think they explain and answer pretty much all the battery questions. The internal voltage regulator is not explained because as a user we really don't need to know what it is doing to operate the detector. But bottom line all it does is only allow the right amount of voltage to operate the detector. So the detector runs on a voltage less than the output of the battery pack and when the battery output drops close or below what the detector needs, the batteries need to be change. The manual says change them at one bar showing on the battery level indicator. The manual also says it will maintain full performance until the batteries need changed. So if your detector is showing 2 or more bars you should be good to hunt.

Ron in WV

 

[DirtShoveller]

So than we can assume that the voltage regulator is set to less than 4.8v?

Why do you think alkaline batteries are still recommended by Garrett?

 

[WV62]

I think you are correct about the less than voltage and I think the alkaline recommendation from Garrett is all about the best battery life (longest run time). The manual states you can use rechargeable.

Just to add a little along the line of batteries, I have a recharger that is made to recharge alkaline type batteries, and I have been running all summer on the same bunch of batteries for all 3 of my detectors.

Ron in WV

 

[firstring]

I realize your main concern is whether or not 4.8 volts vs 6 volts hinders the performance of the AT Pro, specifically depth. I tend to generally hunt parks and schools, so for me depth is not that much of a concern. I will say I did go out one day and and the battery level hit the one bar. I basically forgot about it for the rest of the afternoon as the machine was still zeroing in on targets down to 8". I kind of like digging targets. When the voltage drops on my high end detector, look out - it goes fast and drops dead, no fun at all. Not so on the AT Pro. The end results are there, and that's my main concern. I don't believe there is a perfect machine, but I do think the engineers at Garretts got this bad boy figured out. Happy hunting to all.

 

[William-NM]

I've been using the low self-discharge (LSD) rechargeables for over 6 months and have been very pleased with their performance. I haven't seen any differnce in sensitivity. Take a look at the Sanyo Eneloops on Amazon or feebay, you'll love 'em.

 

[marcomo]

I'm with you, William, LSD rechargables are the way to go with the AT if you want to save money. I've been using them for about a year - there's no performance difference and the hour life is close to alkalines...even using a cheap little 4 battery AA recharger.

Besides Sanyo's Eneloops, Duracell and Energizer also make quality LSDs.

 

[chakra22]

Sounds good, What is the brand name of your recharger that is made to recharge alkaline type batteries

 

[rseasy1]

The voltage regulator that is referred to provides what is called clean voltage to the electronics with out any variance to the voltage via spikes or allowing low voltage to reach the electronics.
When the battery voltage falls down to a certain point the detector will shut down not actually caused by dead batterys but low voltage this is done to protect the electronics
as low or high voltage is not a good thing.
The regulator provides a clean constant voltage to the electronics no matter what state the battery charge is in.Providing there 's enough available voltage!
The difference using the 4.8 vs. the 6 volt would not have a peformance affect on the detector since a clean regulated voltage is used to operate the electronic part of the detector.(constant voltage)