voltmeter/ammeter
 

voltmeter/ammeter  

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ke0pci
(@ke0pci)
Active Member Member
Joined: 10 months ago
Posts: 9
June 18, 2019 9:30 am  

In preparation for FD, I made a battery box, and when collecting parts for that build, I got a cheap voltmeter/ammeter.  It came in a poly bag with no schematics, no documentation (unless some of the chinese text on the bag was supposed to be documentation).  

The hook ups for the device are two bolts, thoughtfully marked "x1" and "x2".  No color code, no wires.

I wrote the source, asking if there is documentation, or more exactly "which is positive and which is ground" and they responded with just this image:

The way I have it wired, the display is not lighting up, so I might have already killed the thing.  If anyone has any hints, I'd like to hear them.  Worst case, this box won't have a voltmeter until I get a replacement after FD. 


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AB0L
 AB0L
(@3d0g)
Trusted Member Member
Joined: 11 months ago
Posts: 84
June 18, 2019 11:52 am  

That one is AC only, and needs 220V at that to work as an ammeter.

Here's the one I used for my box. Works well but slightly pessimistic by about 20mV, which isn't necessarily a bad thing in this use case.

https://www.ebay.com/itm/Mini-DC-100V-10A-Digital-Voltmeter-Ammeter-Blue-Red-LED-Volt-Amp-Meter-Gauge-US/281850122861

AB0L (Formerly N0KAI)
-----
Kenwood TM-V71A, Kenwood TS-590S, Motorola XPR4550, TYT MD-UV380, Kenwood TH-D7A, BTECH UV-5X3, µBITX V5 QRP


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ke0pci
(@ke0pci)
Active Member Member
Joined: 10 months ago
Posts: 9
June 18, 2019 11:59 am  

Jeff, 

That makes way more sense. I'll just have to guess at capacity through FD and replace the meter next week sometime.


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AB0L
 AB0L
(@3d0g)
Trusted Member Member
Joined: 11 months ago
Posts: 84
June 18, 2019 12:15 pm  

If it's a standard AGM deep-cycle, remaining capacity can be had from a voltage reading while under load if you've got a multimeter handy.

12.8+ 100%
12.6  75%
12.3  50%
12.0  25%
11.8  0%

 

AB0L (Formerly N0KAI)
-----
Kenwood TM-V71A, Kenwood TS-590S, Motorola XPR4550, TYT MD-UV380, Kenwood TH-D7A, BTECH UV-5X3, µBITX V5 QRP


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