Question about New Trojan Batteries

arf145

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Nov 4, 2010
484
Beneteau 331 Deale, MD
This winter I installed two new Trojan T-1275 12v batts in parallel for my house bank. The boat's on the hard, but I have plugged into shore power on a couple of boat work days and run my Sterling ProCharge Ultra charger (with temperature sensor) to bring the new batts up to full charge. When I get to the boat, my voltmeter shows the rested bank(no charging for days) is at 12.9 volts--I have nothing drawing on the bank. But when I turn on the charger, it stays in bulk mode the whole day, charging at 14.8v, with a draw of .8 amps or so. I have selected the flooded lead acid profile, and I assume the higher than 14.4 v (or whatever it is supposed to be) is because of the low temps, but why doesn't it ever go to float?
 
Sep 25, 2008
615
Morgan 415 Out Island Rogersville, AL
If you aren't willing to program the charging parameters in for the T1275s, use profile two under 'open lead acid' on your sterling charger--its a surprisingly good fit. The T1275s will be better behaved after they are broken in. Be sure to reboot the sterling once or twice after it first goes into float when charging depleted batteries to reset the sterling's egg timer to get your batteries to 100% charge. Mainsail told me to equalize my T1275s for an hour each week. Good luck.
 

arf145

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Nov 4, 2010
484
Beneteau 331 Deale, MD
Thanks for the info Snotter. I believe I had it on that profile at first because it fit Trojan's specs. But then I became alarmed at how long it had the batts at 14.9 so I switched to Gel or another lower voltage profile temporarily. I kind of wanted to see it go to float while I'm there to watch before I plug the boat in at the dock next week and leave it! So, is this just because the batts really haven't been used yet?
 
Sep 30, 2013
3,538
1988 Catalina 22 North Florida
I bought a Trojan 24TMX for our C22 earlier this year, and it did the same thing when I first charged it. It charged and charged and bubbled and bubbled way longer than it seemed like it should, til I got scared and quit charging it for a while. Wondered if it (or my charger) was defective. It's all good now though.

One amazing thing about that battery, it seems to take a charge off our 60 watt solar WAY faster than my old Duracell Ultra (Deka) ever did. So needless to say, I'm loving it so far.
 
Sep 25, 2008
615
Morgan 415 Out Island Rogersville, AL
My batteries required a massive charge when I got them. The batteries were fresh when delivered to the distributor. I had to order them a week or two before they were delivered to the distributor.
 
Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
Use the temp sensor, set the charger to charge at 14.8V absorption and 13.5V to 13.6V for float, and let the charger do what it does. The absorption cycle was determined by an internal algorithm that actually works quite well and better than most. Setting it to GEL or 14.4V will wind up chronically undercharging your batteries and lead to early failure.
 

arf145

.
Nov 4, 2010
484
Beneteau 331 Deale, MD
It charged and charged and bubbled and bubbled way longer than it seemed like it should, til I got scared and quit charging it for a while. Wondered if it (or my charger) was defective.
Exactly what mine were doing and exactly where I was in my thinking. Don't worry, Maine Sail, I wouldn't have left them at gel, I was just worried that something was wrong and I was cooking my expensive new batts! Anyway, reassured by Gene and MS that all was normal, I switched back to the appropriate Open Lead Acid #2 as Snotter suggested and after a spirited couple more hours at now 15.1v, the charger switched to float. Ahhhh! Thanks all.
 
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Likes: Gene Neill
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Use the temp sensor, set the charger to charge at 14.8V absorption and 13.5V to 13.6V for float, and let the charger do what it does. The absorption cycle was determined by an internal algorithm that actually works quite well and better than most. Setting it to GEL or 14.4V will wind up chronically undercharging your batteries and lead to early failure.
Would you recommend the same settings for Costco GC2 6V batteries? They're made/branded by Interstate and I couldn't get any charging voltage info from Interstate directly. I did find recommendations for Interstate GC-2s here (http://www.cleanenergybrands.com/sh...+Deep+Cycle+Batteries+Charging+Recommendation) of Absorption 15.3 (seems too high!), Bulk 14.46, Float 13.4, and Equilization 15.6.