digital meters

[edmo]

I am looking for a parasitic drain on the starting battery with a digital meter and when I unhook the ground and span meter leads from battery neg. to neg. cable I get 95 on every meter range. So I don't know if it is 95 microamps, 95 mA or 950 mA. I tried another digital meter and got the same. Tried an analog meter that maxes at 150 mA and popped a fuse. Anybody know how to interpret these things for amps? volts and ohms is easy and consistent. And I do have the meter's red lead plugged into the 10A port.

 

[H20Rat]

Did you move the leads? Almost every meter I've used requires you to plug the leads into a different set of holes on the DMV. If you didn't do that and the meter requires it, the meter is probably now shot...

The other thing with measuring like that... It isn't good to do on any boats that have computers. MUCH better to troubleshoot at the fusebox instead.

 

[bruceb58]

If he left the leads in the Volt position he is still fine. Just needs to move to the amps position.

Using a DVM on a boat with a computer is fine. The only time a DVM puts out a voltage is in ohms mode and with modern meters, its a very tiny voltage.

To the OP, put the meter in the 10A range, move the leads so that they are in the correct spot, measure your current and snap a picture of the display and post it.

See the meter below? The 2 inputs on the left are where you plug in the positive lead to measure current.

 

[midcarolina]

I am looking for a parasitic drain on the starting battery with a digital meter and when I unhook the ground and span meter leads from battery neg. to neg. cable I get 95 on every meter range. So I don't know if it is 95 microamps, 95 mA or 950 mA. I tried another digital meter and got the same. Tried an analog meter that maxes at 150 mA and popped a fuse. Anybody know how to interpret these things for amps? volts and ohms is easy and consistent. And I do have the meter's red lead plugged into the 10A port.

The op stated that he did put the pos meter lead in the 10 amp socket of meter, It sounds like you are testing for current correctly, make sure you select the amp setting on your meter........ always check potential draw with highest setting, then once you determine the draw is less than the max allowed mA draw of the meter you can switch to MA to get a better reading. the only difference between the 10 amp scale and the MA scale ( as far as readings) is a decimal point and a little accuracy.

try this to verify meter operation.........grab a trailer marker light wire neg to neg term of battery then wire your meter leads in line with the positive wire.... when power is applied you will read the current draw.

 

[edmo]

My meter is just like Bruces only 10A port is unfused. Older boat w/o computer. Selecting amp range without load moves decimal point. I'm sitting here thinking that when testing the circuit it read .95 on every range, which prompted my post. I'm sure it's me and not the new meter. I'll keep at it. Pretty sure I have a drain on battery (tested OK at store after charging) and blew fuse on 150 mA analog meter. From what I've read anything above 50 mA or so indicates a problem. Thanks for the input. This is a great forum.

 

[midcarolina]

You can also go back to old school...... put a test light in series of neg batt term and neg wire......if light comes on there is a draw...then just eliminate one circuit at a time until test light goes out.....

 

[bruceb58]

Good luck seeing a 100mA draw through a test light.

I would use a meter for something like this. He has one. He just needs to understand how to use it.

I would experiment with something easy first. Pull a fuse for the bilge pump stick it in between the fuse terminals and turn it on. That's what a 1A or higher load looks like. He can compare that to what he saw before.

 

[glenn property of pam]

edmo if you are reading 0.95 amps in the 10amp range it will still read 0.95 amps in the 1amp range. So you have a 0.95amp draw or 950ma draw.

set to the 10 amp range and turn on a light the reading should go up to confirm the meter is reading correctly

 

[Pez Vela]

I'm no electrician so I had to make troubleshooting easy on myself. I purchased a clamp meter. I read the directions. I spoke to tech support on how to interpret the readings. I now feel reasonably competent. There are many choices for clamp style DVM's, but I chose the Blue Sea. It's all about having the right tools for the job, just like everything else.

 

[bruceb58]

A clamp meter that measures DC is going to be way over $100. He should be able to tackle this with what he already has. I am thinking the same as glen that he has a 950mA draw.

 

[midcarolina]

Good luck seeing a 100mA draw through a test light.

I would use a meter for something like this. He has one. He just needs to understand how to use it.

I would experiment with something easy first. Pull a fuse for the bilge pump stick it in between the fuse terminals and turn it on. That's what a 1A or higher load looks like. He can compare that to what he saw before.

If he is actually seeing .95 amp that is enough to light a tester.... a single lamp marker light pulls less than a amp..............

It's a simple boat electrical system......... NOT a modern vehicle with electronic everything

 

[bruceb58]

If he is actually seeing .95 amp that is enough to light a tester.... a single lamp marker light pulls less than a amp..............

It's a simple boat electrical system......... NOT a modern vehicle with electronic everything

He has a meter. All he needs to do is learn how to use it.

 

[sam am I]

LOL..........Here this might help, this guy is a bit freaky and less his water analogies which are "okay" I guess, he does a good clean job of explaining basics, meter setup/use and is thorough. Video quality, lighting, sound and editing is set up nice too!! AND, he uses flukes and tektronix's !! That's at least a "B" grade in my book at the get go.

The guy's work bench in his bedroom too!!..........Hmmmm, sleeps with his tools? Wow

I have no idea whats all been said above ^^^^ not reading it all, but Part 2A as I glanced at the post relates well here I think(Part 2 is mainly current clamps looks like) .......When in doubt, YouBoob!!

https://www.youtube.com/watch?v=ZBbg...list=PL4A0248A E2B0DF1A3

 

[edmo]

I learnt' how to use it now the next question. The positive connection to the battery had the main feed to the battery plus three other auxiliary wires to the console area. A 12 gauge orange wire was one of them and it went to the auxiliary switch on the console (has to be keyed on for bilge, livewell pump, lights, etc.). This was the one that had the amp draw. So, I went up to the console and tested continuity from where it connects to the switch back to the battery connector. Found a couple 100 ohms. Unscrewed the wire and tested continuity in just the wire and had the same resistance. Sooo, went back and saw a fuse in the line near the battery. Took the fuse holder out, cleaned out it and some kind of gunk that looked like it had seeped out from the metal-glass connection of the fuse. Put it all back together and no resistance.

Could something like that have caused an amp leak or maybe I made some bad connections when reading the meter along the way?. I know enough about DC circuits to really confuse myself most of the time.

 

[sam am I]

Ya might want to view all the video's.........."Series" and "parallel" resistance sections.

The "parasitic" you're after draining your batt. is a rouge parallel resistance to your normal loads. Your fuse issue just found, is series resistance to your loads that limits current. Series resistance would actually slow batt drain by limiting(or stops, if high enough...."an open") current to the normal given load/s. A drawing might help if your still stuck later but, I have to go catch fish now,.....GL

 

[bruceb58]

So, I went up to the console and tested continuity from where it connects to the switch back to the battery connector. Found a couple 100 ohms.

Keep your meter measuring current at the battery cables and remove wires one at a time at the console switch until you see the current drop to zero. You need to identify the exact path that is causing your current drain

Measuring the resistance is not telling you anything. By the way, measuring resistance in a circuit that has power applied to it will give you a false reading. Don't worry about measuring resistance at this point.

 

[glenn property of pam]

Yours is losing charge which means that some electricity is leaving via the positive and going to the negative when you don't want it to. The meter says that there is 0.95 amps leaving the positive when everything is switched off. It can only go back to the negative so its being used somewhere.
line resistance, load resistance is not a useful measurement as all positive wires after a switch should read ohms as that's the load before it goes to the negative terminal. Only resistance to hull or resistance on a item that is mean to be open will be helpful.

you found that one cable that goes to the console is pulling 0.95 amps you chased that to a switch. You say that the switch is only on when the key is on.
If its using 0.95 amps then either the statement that the key has to be on is wrong or there is a way where electricity can by pass the switch.
I would test the back of the bilge pump switch to see if it has 12v, I would also check if I had a radio where the memory is getting its power from. Disconnect wires and see if the amp draw goes to near zero and that is the device that is draining the battery. If one wire kills 6 things then go to where the one wire splits to 6 things then test then one at a time.
http://forums.iboats.com/forum/boat...ttery-that-goes-flat-in-a-short-time?t=583537

glad to see the pics are back on the forum

 

[midcarolina]

He has a meter. All he needs to do is learn how to use it.

So if it's not your preferred way it's the wrong way?

It is another option that the op or anyone else who may read this thread can use, and using the test light is especially helpful if someone is troubleshooting alone.....much easier to see the light than constantly picking up the meter.........

Some times it pays to keep things simple...........

 

[midcarolina]

I learnt' how to use it now the next question. The positive connection to the battery had the main feed to the battery plus three other auxiliary wires to the console area. A 12 gauge orange wire was one of them and it went to the auxiliary switch on the console (has to be keyed on for bilge, livewell pump, lights, etc.). This was the one that had the amp draw. So, I went up to the console and tested continuity from where it connects to the switch back to the battery connector. Found a couple 100 ohms. Unscrewed the wire and tested continuity in just the wire and had the same resistance. Sooo, went back and saw a fuse in the line near the battery. Took the fuse holder out, cleaned out it and some kind of gunk that looked like it had seeped out from the metal-glass connection of the fuse. Put it all back together and no resistance.

Could something like that have caused an amp leak or maybe I made some bad connections when reading the meter along the way?. I know enough about DC circuits to really confuse myself most of the time.

Double check that none of the aux switches have power with the key off........that would be some what odd to have to have the ignition hot to run the bilge pump or the anchor ( rear ) light, and certainly not the livewell pump

 

[bruceb58]

So if it's not your preferred way it's the wrong way?

It is another option that the op or anyone else who may read this thread can use, and using the test light is especially helpful if someone is troubleshooting alone.....much easier to see the light than constantly picking up the meter.........

Some times it pays to keep things simple...........

A meter will always work in all cases. A light would work if there was enough current to light the bulb.

Like I said, the OP has a meter. It's the better of the two tools.

Let's say he has 2 items that are drawing down his battery. One is an 800mA load and one is 100mA. He uses his test light to find the 800 yet gives up thinking he has solved his problem . With a meter, he will know he has to investigate more. I keep a Fluke meter in my boat at all times. I have needed to use it 17 miles off shore before.