Proper way to test batteries
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OP
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firstbase
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I am an EE and batteries and DC have kicked my ass since college, give me networks or antennas any day, there is a reason Edison's DC lost out to Westinghouse"s AC, gave too many people a headache
Thanks, makes me feel a little less dumb. Supposedly (from PO) the only thing on the start battery was engines and generator. We shall see. I was going to check out any ghost draws the next time I am on the boat. I think, not sure, that even I can do that.
A 2.5 year old lightly used battery should be able to hold a charge for a month. Something out of whack has to be taking it down.
FF
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"there is a reason Edison's DC lost out to Westinghouse"s AC, gave too many people a headache'
AC was easy to transform to send a distance with modest osses.
Today DC is king of very long distance power transmission.
Over a million volts with buried cable.
https://new.siemens.com/global/en/p...ge-direct-current-transmission-solutions.html
'AC was easy to transform to send a distance with modest osses.
Today DC is king of very long distance power transmission.
Over a million volts with buried cable.
https://new.siemens.com/global/en/p...ge-direct-current-transmission-solutions.html
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Simi 60
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We had or have an interesting start batt issue.
Went into a fuel dock a week or two ago and when we went to leave we could barely get any crank from 2 x n150 @ 24v
We had a few hours earlier started and pulled up anchor but only motored for about 1nm so thought maybe it was not enough of a run to charge up.
Connected 60amp charger, spun up genset and we were away again, motored several hours , checked battery for increasing charge while underway and thought no more on it.
Yesterday I went to start and same story but this time I checked voltage, said 12.6 or close two in both, hooked up charger and it was instantly in float adding bugger all amps but this time it still wouldn't crank.
Batts reading 13+v
All connections on batt and starter motor are clean and tight.
Using a cheap battery tester shows the batteries are OK, not good but certainly no where near the bad sector.
I took out one of the batts and replaced it with one of the older spares and we were on our way again.
Test start this morning using the old replacement and still starting, strong as.
Could a bad cell cause the above issues?
Went into a fuel dock a week or two ago and when we went to leave we could barely get any crank from 2 x n150 @ 24v
We had a few hours earlier started and pulled up anchor but only motored for about 1nm so thought maybe it was not enough of a run to charge up.
Connected 60amp charger, spun up genset and we were away again, motored several hours , checked battery for increasing charge while underway and thought no more on it.
Yesterday I went to start and same story but this time I checked voltage, said 12.6 or close two in both, hooked up charger and it was instantly in float adding bugger all amps but this time it still wouldn't crank.
Batts reading 13+v
All connections on batt and starter motor are clean and tight.
Using a cheap battery tester shows the batteries are OK, not good but certainly no where near the bad sector.
I took out one of the batts and replaced it with one of the older spares and we were on our way again.
Test start this morning using the old replacement and still starting, strong as.
Could a bad cell cause the above issues?
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BruceK
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Maybe reinstall the battery that didn`t start the engine and see what happens. Could the connections at the batt have been the problem? If it fails again it must be the batt, but why,if it tests ok.
Simi 60
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I would have thought solenoid or starter would be click, not slow crank
Connections clean, cables shiney copper when peeling tape back.
Batts off boat now, dinghy in and waiting for a battery guy to turn up and test with a real load tester and a new pair.
From what I can guess they are 2013 vintage so past theoretical use by date
Connections clean, cables shiney copper when peeling tape back.
Batts off boat now, dinghy in and waiting for a battery guy to turn up and test with a real load tester and a new pair.
From what I can guess they are 2013 vintage so past theoretical use by date
Simi 60
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So this all relates back to a post I made a while ago about getting a false sense of security.
Our inverter charger has a trickle charger tap coming off of it specifically for the start batteries.
Voltage always showing around 12.6 to 13v
Cheap battery tester identical to the harbour freight one mentioned, showed them to be OK, not perfect but in the green when quite obviously they were not.
Anyway, batts are in, engine starts in a heartbeat and we are back out there on the wobbly stuff.
Our inverter charger has a trickle charger tap coming off of it specifically for the start batteries.
Voltage always showing around 12.6 to 13v
Cheap battery tester identical to the harbour freight one mentioned, showed them to be OK, not perfect but in the green when quite obviously they were not.
Anyway, batts are in, engine starts in a heartbeat and we are back out there on the wobbly stuff.
OP
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firstbase
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How did you load test them?
Simi 60
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I load tested them with the yum cha/eBay/harbour freight type tester as shown in post
The battery guy had a substantially beefier bit of kit that did similar I guess but he also had an analyser that said how many CCA it was vs how many CCA it actually is now
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