Battery question
The only practical way to test an automatic battery charger is to attach it to a known good battery and see if it fully charges the battery. In addition you could put a voltmeter on the known good battery while it is charging and monitor the changes. Try it on your car or truck battery.
The microcontroller inside the battery tender expects a battery to be attached - it will not function if you attach anything else like a voltmeter or an ammeter.
Last edited by IronMick; Mar 11, 2011 at 09:05 PM.
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From: Minnesota
Well I would say that if you checked the output of your tender with a voltmeter, and it is putting out between 12 & 13 volts you could assume that it is working. Regardless of what amperage it is, it has to put out 12 volts or better or it won't charge your battery, plain and simple.
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Joined: Jul 2009
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From: Minnesota
I have not heard of this before now, but i suppose it could be true.
The only practical way to test an automatic battery charger is to attach it to a known good battery and see if it fully charges the battery. In addition you could put a voltmeter on the known good battery while it is charging and monitor the changes. Try it on your car or truck battery.
The microcontroller inside the battery tender expects a battery to be attached - it will not function if you attach anything else like a voltmeter or an ammeter.
The only practical way to test an automatic battery charger is to attach it to a known good battery and see if it fully charges the battery. In addition you could put a voltmeter on the known good battery while it is charging and monitor the changes. Try it on your car or truck battery.
The microcontroller inside the battery tender expects a battery to be attached - it will not function if you attach anything else like a voltmeter or an ammeter.
Mine is a battery tender, same as the OP. I tried the same procedure and nothing on either the voltmeter or the ammeter.
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Joined: Jul 2009
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From: Minnesota
. Obviously doesn't have the same circuitry as the ones you guys have, I've had it for many years.So it won't fire up even if you run the ammeter in line with one of the output leads and connect to battery?
I guess you could record battery open circuit voltage and then put the tender on it, then take another readng right away. Should be able to note an increase within a few minutes I would think with a digital meter anyway.
Last edited by Blackcherry Low; Mar 12, 2011 at 08:18 AM.
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From: Minnesota
I just checked the current flow on mine and it's been running on the battery all winter long. Disconnected from the battery, the charge voltage is at 12.77 and the battery on it's own is the same. Put the ammeter in line and it pulls 380 milliamps in the battery's current state.
They only cost 12 bucks from harbour freight and it's been working for many years. Not to mention that you can check it's operation quite easily. Might be worth the peace of mind know that it's working as opposed to the more expensive/sophisticated ones.
They only cost 12 bucks from harbour freight and it's been working for many years. Not to mention that you can check it's operation quite easily. Might be worth the peace of mind know that it's working as opposed to the more expensive/sophisticated ones.
Last edited by Blackcherry Low; Mar 12, 2011 at 09:53 AM.
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Joined: Jul 2009
Posts: 481
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From: Minnesota
Did you have your ammeter set up for milliamps? Also with all the meters I've owned, you don't typically have to move the leads to read milliamps. My meter didn't pick up anything until I switched it to mA.
Last edited by Blackcherry Low; Mar 12, 2011 at 09:02 AM.
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