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Old 02-11-2018, 15:06   #16
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Re: Rapid voltage drop under small loads with new Trajan T-105

Are you positive that your load is only drawing 8A?
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Old 02-11-2018, 20:46   #17
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Re: Rapid voltage drop under small loads with new Trajan T-105

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I talked to Trojan today and they suggested it might take 50 full cycles for the batteries to deliver their full capacity. They said capacity might be as low as 80% of rated capacity upon leaving the factory.

And the dealer didn't know about this?
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Old 04-11-2018, 03:31   #18
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Re: Rapid voltage drop under small loads with new Trajan T-105

Hmm besides... 4 x 105Ah = 405 Ah
8A x 12 hrs = 96 Ah
50% Discharge should be 12,2V = 202,5 Ah
Assuming you should have 12,4V on 100Ah
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Old 04-11-2018, 07:45   #19
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Re: Rapid voltage drop under small loads with new Trajan T-105

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And the dealer didn't know about this?
Very few people know this, even among the professionals.

It is the owner's job to commission charge their bank properly, just like breaking in a new engine.

Very few bother, nor notice the capacity increase that naturally happens later anyway.

Most just say crazy to pay close attention to such details, see comments like that here all the time.

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Old 04-11-2018, 07:53   #20
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Re: Rapid voltage drop under small loads with new Trajan T-105

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Originally Posted by moseriw View Post
Hmm besides... 4 x 105Ah = 405 Ah
8A x 12 hrs = 96 Ah
50% Discharge should be 12,2V = 202,5 Ah
Assuming you should have 12,4V on 100Ah
Where did you get 105AH?
T-105s are 225AH @6V tge 20-hour rate is standard for apples to apples comparison.

A pair serial'd to get to 12V is still 225AH.

Only paralleling increases the AH capacity.

So 4 batts in 2P2S configuration yields 450AH @12V.

8A load over 7 hours of course is 56AH, or 12.5% DoD.

And no idea where that 12.4V vs 12.2V is from, what it is supposed to mean?
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Old 05-11-2018, 06:32   #21
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Re: Rapid voltage drop under small loads with new Trajan T-105

yes, I am positive about the current draw.
After 2-3 slow, full (or nearly full since V was only at 14.5 with the CTEK charger) recharges and one deep discharge, it appears that the batteries are behaving much closer to specs. They seem to be maintaining voltage under load much longer than the first batch. I'm in the process of procuring a power supply to perform equalization as I noted some (small) difference in SG between cells after full recharge.
Thanks all for the feedback.

Cheers,
Julien
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Old 05-11-2018, 07:08   #22
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Re: Rapid voltage drop under small loads with new Trajan T-105

It will be important for longevity that you get them to 100% Full as quickly and often as possible.

98-99% Full is **not** "almost as good"

Charger should be able to put out temperature-corrected 14.8-15V, and your ammeter verifying it is holding that V until amps taper to 2A or below, however long that takes, aka .005C endAmps.

Let SG go a bit over spec, no harm occasionally.

Do this at least 3-4 times a week in regular cycling usage, ideally your various charge sources set to do this automatically.

As well of course as 'step zero' before following Trojan's equalizing protocol, at least once a month if possible.

And this is just part of the routine care; when you can, try to follow the "commissioning charge" protocol above, gentle but deep discharge immediately followed by a Full but gentle recharge.

At the end of a gentle ~50 cycles, you should have a full capacity, great platform for many years of reliability.
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Old 05-11-2018, 10:15   #23
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Re: Rapid voltage drop under small loads with new Trajan T-105

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Originally Posted by BluJu View Post
yes, I am positive about the current draw.
After 2-3 slow, full (or nearly full since V was only at 14.5 with the CTEK charger) recharges and one deep discharge, it appears that the batteries are behaving much closer to specs. They seem to be maintaining voltage under load much longer than the first batch. I'm in the process of procuring a power supply to perform equalization as I noted some (small) difference in SG between cells after full recharge.
Thanks all for the feedback.

Cheers,
Julien

Any luck checking the specific gravity of your cells when you think they are fully charged?
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Old 05-11-2018, 12:46   #24
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Re: Rapid voltage drop under small loads with new Trajan T-105

Quote:
Originally Posted by BluJu View Post
yes, I am positive about the current draw.
After 2-3 slow, full (or nearly full since V was only at 14.5 with the CTEK charger) recharges and one deep discharge, it appears that the batteries are behaving much closer to specs. They seem to be maintaining voltage under load much longer than the first batch. I'm in the process of procuring a power supply to perform equalization as I noted some (small) difference in SG between cells after full recharge.
Thanks all for the feedback.

Cheers,
Julien
How does a power supply equalize batteries wired together?
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Old 05-11-2018, 13:08   #25
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Re: Rapid voltage drop under small loads with new Trajan T-105

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How does a power supply equalize batteries wired together?
He likely means a variable bench top type power supply with a voltage dial and a current dial. I use them in the field all the time when decommissioning boats for winter storage. This is a 0-30V, 0-30A model equalizing a Trojan flooded battery before winter storage. I usually EQ each battery individually but you could do the whole bank.


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