Problems replacing 4D Batteries with Trojan T-145's

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Mike Dwyer
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Joined: Thu Nov 03, 2005 2:39 pm

Problems replacing 4D Batteries with Trojan T-145's

Post by Mike Dwyer »

I have a 2004 Catalina 350 sailboat #149, I replaced two 4D Nautilus batteries (180 Amp hour/12V each) with four Trojan T-145 6V batteries with two sets wired in series as my house battery (260 Amp Hour/12V pair). I have not been able to get the new batteries fully charged. My 120V charger is a Charles 30 AMP 5000 series, my on engine alternator is 50AMP, I ran the 120V charger 48 hours and got to 12.7V or so on the batteries but never showed the 13+V that the 4D batteries showed when fully charged.

Seems like the 30AMP charger should be able to get them there. I checked the charger voltage (unloaded) it was still at 14+V. After 48 hours the charger showed it was still putting out 5 AMP, with my 4D's after about 12 hours it would sit at just about 0 Amps maintaining charge. I will check the specific gravity of each battery this weekend but don't expect to see any issues as I just bought them last week. I wired the batteries as suggested on the Catalina website - 2 6V batteries in series (+ to -) , the 2 sets wired in parallel (+ to +, - to -)

Thoughts,?
Will the Charles 30AMP get the new batteries to fully charged?
Have others with 6V golf cart batteries seen this?
Mike Dwyer
"Nautilus"
C350 Hull 149
KenKrawford
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by KenKrawford »

Mike, I have much the same setup as you (T105's instead of T145's) and the same Charles charger. If you were able to charge your 4D's ok, then you'd have to suspect the new batteries. On the other hand, the charger should see that the voltage is still low and keep putting out a charge. Frequently I'll run my bank near or below 50% and the charger always has them recharged within 24 hours. I'll be curious to see what you measure for specific gravity. Keep us posted.
Ken Krawford
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C350 # 351
Lake Lanier, GA
wolfe10
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by wolfe10 »

Only two possibilities I can think of:

Bad battery or loose or poor connection between batteries and charger.

Poor connection= resistance. So the charger could be putting out 14, but you could be loosing a volt or more in poor connections.

Brett
Brett Wolfe
C350 #180
"Vindaloo"
Ft Myers FL
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by russp »

Hi Mike,
By coincidence, I have hull #150 and am based in southern Australia. Re batteries, I have been having a brawl with Volkswagen for past 3 weeks and have done a lot of research on the topic and have found out the following.
1) A lot of car mechanics haven't got a clue about batteries, one senior guy told me "it is a 12V battery, if it is over 12V it is fine!"
2) I always thought 6 x 2.2V cells in a 12V battery, so 13.2V in a fully charged battery, however appears not so -
3) There is heaps of info on net that suggests 12.6-12.8V is a battery charged to 100% (6 x 2.1V per cell), you may see a higher voltage immediately after charging, but let it rest for 24 hrs and you should see 12.6-12.8V across a fully charged, good condition battery (same for 2 x 6V in series)
4) As a battery ages this rest voltage falls so you won't see 12.6+V on a battery that won't recover to 100% charge (and it does vary with electrolyte density apparently, and not all manufacturers use same electrolyte density - maybe they find a little longer life if they run slightly more dilute? Who knows)
5) The battery gauge on Avalon shows 100% charge for over 12.6V, yellow zone from 12.2-12.6, and red zone for below 12.2 so aligns with above theory
6) If your battery charger is still putting 5A into the batteries it still thinks they aren't fully charged. Have you got a smart charger that backs off to a float voltage, and are you using the correct temperature compensation? Pushing 5A into a fully charged battery for any length of time will just slowly gas the battery and dry it out.
7) I don't buy the bad connection problem, that would make the battery charger see a higher battery voltage than actual and back the charge voltage off sooner, but you are still seeing 14.4V or so hence full charger output across the batteries.
8) The battery should "fill up" and accept no more charge by its internal voltage rising towards the charger voltage and stopping the current, yours doesn't seem to be doing this and is may be because there is a fault, or maybe a characteristic of the battery and needs a lower float voltage than your charger is giving it. I.e. an AGM battery setting only has 13.2V coming out of the battery charger when they are "full", 14.4V will keep "pushing" current into the full battery and eventually dry it out! Happens (personal experience) and very expensive.

Hope all of above is more help than hindrance,
Regards
Russ Peel :? :? :?
Russ Peel
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by wolfe10 »

Russ,

I guess my take is that if charge amps are down to 5 and voltage at the batteries is only up to 12.7, there IS a problem.

Could be a connection issue, a charger issue, or, a battery issue or even an inaccurate voltmeter.

Mike, have you confirmed voltage with a good digital voltmeter and checked that all connections are clean and tight?
Brett Wolfe
C350 #180
"Vindaloo"
Ft Myers FL
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by jbd3 »

I have 4 T145s for a couple of years now Balmer 80 amp alternator, Link system and external regulator. All works well in hull 394. I'd look at cell hydration and connections..
Mike Dwyer
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by Mike Dwyer »

Well good news, I think.
I checked all the cells (specific gravity good), installed all the correct 1/0 gauge cables (I had a couple of 4 Gauge before), and ran a 96 hour charge. The batteries got to 13.3 and were holding with about 1AMP from the charger. I ran an overnight test drawing 5AMP's (mostly the refrigerator), then recharged in the morning, took about 2 hours and back to 13.3 and holding.
So... I should have done all that from the beginning. The Trojan manual said an "initial charge" in the final battery configuration was required, also said the batteries peak performance is after they break in. An important point which I had not considered is the optimal charging current for flooded batteries is 10-13% of capacity, With my 520 AmpHours capacity that is 52-68AMPs from the charger. The 30 AMP charger will do it but take twice as long and not be the "optimal" charging current. The Charles 60AMP charger is about $800 (which I am not buying at the moment) so maybe I should have gone with the T-105 batteries at 450 AMP Hours, closer to the old 4D total of 360 AMP Hours and better suited for a 30AMP charger. Oh Well.
But wait... my boat neighbor has just installed two 220 Watt solar panels and says it tops off his batteries each morning by noon. He doesn't plug in his boat anymore. So lets see, rather than get a new charger I could add the solar cells........
Mike Dwyer
"Nautilus"
C350 Hull 149
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by wolfe10 »

The recommended charge rate of 10-15% of battery amp hr rating is pretty much a carry over from the old "STUPID" charger days.

The new 3 stage smart chargers, particularly those with battery temperature sense wire can safely charge at quite alot higher rates without battery damage. But, slower charge is easier on the batteries AND the right way to go if you have shore power.

The higher charge rates benefits come into play when you are running your generator ONLY to charge the batteries. For all other situations, the higher output chargers are a moot point.

Brett
Brett Wolfe
C350 #180
"Vindaloo"
Ft Myers FL
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Re: Problems replacing 4D Batteries with Trojan T-145's

Post by TBOT422 »

Mike,

r.e.
installed all the correct 1/0 gauge cables (I had a couple of 4 Gauge before)
Are you referring to the cable connecting the 2 6V batteries to each other? The Charles manual for the 30-amp charger recommends 8-10 AWG for the cable from the charger to the battery. It would seem to me that when switching from the 4D to a 6V bank, the short cable connecting the 2 6V batteries would be the only 'new' cable you were adding.

I am considering a similar change when my old 4D batteries finally give up.

Thanks
Gary & Janet
The Best of Times (Hull #422)
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