Battery life effect on depth

[Paul Revere’s Ghost]

Greetings. I recently took my old Whites surfmaster pi out of mothballs. I’ve had it about 30 years. I used to write for all the treasure magazines and lived at the beach in and under the water. My question is, at what point of discharge do 1.5 v batteries effect the depth capacity of a PI coil? The owners manual says when the test sound is loud the batteries are good. When it’s soft replace them. But I don’t want to log miles of hunting at limited depth. Occasionally I’ll dig a pull tab or small rusty nail at 18”. But I changed out the batteries 3 hours ago and yesterday didn’t find anything deeper than about 6”. Strange. I don’t mind load testing batteries every hunt. Thank you for any assistance.

 

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[pepperj]

Greetings. I recently took my old Whites surfmaster pi out of mothballs. I’ve had it about 30 years. I used to write for all the treasure magazines and lived at the beach in and under the water. My question is, at what point of discharge do 1.5 v batteries effect the depth capacity of a PI coil? The owners manual says when the test sound is loud the batteries are good. When it’s soft replace them. But I don’t want to log miles of hunting at limited depth. Occasionally I’ll dig a pull tab or small rusty nail at 18”. But I changed out the batteries 3 hours ago and yesterday didn’t find anything deeper than about 6”. Strange. I don’t mind load testing batteries every hunt. Thank you for any assistance.

Query: were you digging the 18" targets pre/post of taking it out of the mothballs?

If post and after battery change I'd look at changing them out again and testing voltage.
1/3 the depth is a huge difference.

 

[Paul Revere’s Ghost]

Query: were you digging the 18" targets pre/post of taking it out of the mothballs?

If post and after battery change I'd look at changing them out again and testing voltage.
1/3 the depth is a huge difference.

Query: were you digging the 18" targets pre/post of taking it out of the mothballs?

If post and after battery change I'd look at changing them out again and testing voltage.
1/3 the depth is a huge difference.

Hmmm. Good question. I’m not sure if I’ve had any real deep digs since the swap. I’ve only detected a shallow cuts at two adjacent beaches for about 1 1/2 hours each. So I just tested the battery pack and it’s putting out 11.74 v. Seems normal for that amount of use. But maybe I’m not explaining my question right. What I’m wondering is, let’s call that .5% depleted cuz I’m not a math wizard. So now, is the depth depleted by .5% as well? Or will the machine keep performing at 100% depth until the power gets really low? Like 75% or something. The reason I’m asking is because if I’m going to be hunting above the surface line I know targets don’t sink very far. Ever. Unless there’s big wind erosion. So if I’m going to keep hunting the dry I’ll keep using the same batteries. But if I’m going in the water I want 100% regardless of the cost of batteries with gold at over $3K an ounce. Hope that makes sense. Thank you for your reply.

 

[Paul Revere’s Ghost]

Hmmm. Good question. I’m not sure if I’ve had any real deep digs since the swap. I’ve only detected a shallow cuts at two adjacent beaches for about 1 1/2 hours each. So I just tested the battery pack and it’s putting out 11.74 v. Seems normal for that amount of use. But maybe I’m not explaining my question right. What I’m wondering is, let’s call that .5% depleted cuz I’m not a math wizard. So now, is the depth depleted by .5% as well? Or will the machine keep performing at 100% depth until the power gets really low? Like 75% or something. The reason I’m asking is because if I’m going to be hunting above the surface line I know targets don’t sink very far. Ever. Unless there’s big wind erosion. So if I’m going to keep hunting the dry I’ll keep using the same batteries. But if I’m going in the water I want 100% regardless of the cost of batteries with gold at over $3K an ounce. Hope that makes sense. Thank you for your reply.

Oh sorry. And yes. 18 and 24” before and after mothballs. I chased a signal so deep once water kept oozing into the hole and washing the sides down. I finally stopped digging. My buddy asked if I was done with that spot and I said yes. After confirming a was sure, he jumped right in the hole over his duck boots with just a shovel and dug and dug and then detected what came out. Got the biggest Mens gold ring I’ve ever seen. Taught me to never give up way out at low tide.

 

[vpnavy]

I moved ya from HELP! over to BRANDS > WHITE's for more exposure.

NOTE: Forum HELP! contains guides tutorials on how to use the new TreasureNet.com software.

 

[achanceforgold]

Hmmm. Good question. I’m not sure if I’ve had any real deep digs since the swap. I’ve only detected a shallow cuts at two adjacent beaches for about 1 1/2 hours each. So I just tested the battery pack and it’s putting out 11.74 v. Seems normal for that amount of use. But maybe I’m not explaining my question right. What I’m wondering is, let’s call that .5% depleted cuz I’m not a math wizard. So now, is the depth depleted by .5% as well? Or will the machine keep performing at 100% depth until the power gets really low? Like 75% or something. The reason I’m asking is because if I’m going to be hunting above the surface line I know targets don’t sink very far. Ever. Unless there’s big wind erosion. So if I’m going to keep hunting the dry I’ll keep using the same batteries. But if I’m going in the water I want 100% regardless of the cost of batteries with gold at over $3K an ounce. Hope that makes sense. Thank you for your reply.

i don't know your metal detector.
But most electronic device have a cascade drop off below the recommended voltage.

A good comparison is a car battery. When it starts getting into the 11+volts range instead of 12+volts you will see performance drop.
I just ran into this on an industrial controller (a PLC) that was supposed to be supplied with 24vdc. the unit wouldn't boot up. It was only receiving 23.2 vdc.

So, i would recommend keeping fresh batteries. I know it gets expensive, but it should help your performance.
Have you looked at rechargeable batteries?

But as to a performance curve on your machine with voltage. Your metal detector supplier may have that available. I looked and was unable to find it on line.

Is this the unit that has a battery test button?

 

[Paul Revere’s Ghost]

i don't know your metal detector.
But most electronic device have a cascade drop off below the recommended voltage.

A good comparison is a car battery. When it starts getting into the 11+volts range instead of 12+volts you will see performance drop.
I just ran into this on an industrial controller (a PLC) that was supposed to be supplied with 24vdc. the unit wouldn't boot up. It was only receiving 23.2 vdc.

So, i would recommend keeping fresh batteries. I know it gets expensive, but it should help your performance.
Have you looked at rechargeable batteries?

But as to a performance curve on your machine with voltage. Your metal detector supplier may have that available. I looked and was unable to find it on line.

Is this the unit that has a battery test button?

 

[Paul Revere’s Ghost]

Thank you for that. I keep finding instances where voltage may or may not matter. Like the time I removed my cars gas tank to test the fuel pump. A 9 volt battery worked the pump on the floor in a bucket but didn’t create enough pressure to fire the injectors. Learning the hard way is my specialty. So the suns coming up and the beaches were full of people yesterday for the first time. Going to go there now and pay closer attention to depth. With that, I’ll keep the load tester in the treasure wagon and fresh batteries and change them respectively to the probability of finding deep gold where I’m hunting. RECHARGABLE batteries only put out 1.4v as opposed to 1.5 so I would have to use ten instead of 8, and there’s not enough room in the submersible box for that. Thank you so much. I believe my question is answered. Since the tide is full high right now I’ll rerun these slightly used batteries in the dry sand this morning. Have a blessed day.🙏 Life’s a beach. 🏖️