Continuing my quest to learn everything I can about batteries and charging...Moved on from the group 24 Interstate, may mess with it more later. Also put the hydrometer with the floating balls where it belongs - under the rear dual. Then I tossed Pinocchio (the EZ-Red) and got a real hydrometer. The batteries - two brand new Trojan T-105s, fully charged. SG in all six cells was 1.275 - 1.280, temp 70F. Put them in series and applied a 12A load for 6 hours bringing the SOC down to about 60-65% and measured the SG at about 1.205. Then separated them to charge individually. The charger I currently have is a Schumacher SC-10030A which is 30A and can do 6V/12V. Bulk charging began at about 6.5V and rose over the next few hours to about 7.1V and then stayed there for a while. So far so good. Trojan says absorption should be at 7.4V so my concern was that it would never get that high, since that seems to be the most common problem. Boy was I was surprised when the next time I looked, the voltage was 8.1V! Even their recommended equalization charge is only 7.75V, so I turned it off but first got this video: T-105 videoI have read here that some bubbling is good, but you don't want it to be a "rolling boil." Rather than try to guess which I have, I posted the video to see what you guys think. I still plan to go full manual in the future with a Megawatt or Meanwell. In the mean time however, the Schumacher is what I have and I wanted to give it a chance to see how it performs. Like I said, I figured if anything it wouldn't ever get high enough, I sure wasn't expecting 8.1! Next, I'll try switching it to 12V and charging them both together in series. My overall goal is to take really good care of these batteries so they will last me a long time. I don't want my battery vendor sending me free calendars!

I have a mega and a mean well. Do it right the first time and get the mean well. Get the model that has a range of something like 13.5 to 17. It will give you the ability to equalize and let the converter do the float. OR just use a progressive dynamics converter for the basics and go solar. :)

rjxj wrote:I have a mega and a mean well. Do it right the first time and get the mean well. Get the model that has a range of something like 13.5 to 17. It will give you the ability to equalize and let the converter do the float. OR just use a progressive dynamics converter for the basics and go solar. :)Good to know, thanks! As far as PD and solar, all of this is happening in my garage now. I plan to always store and charge them in the garage as well.

I hope that you are not thinking about removing the battery and storing it in your garage between trips. That is not a requirement for long battery life. Certainly do not overcharge them, as melted battery plates are worse for battery life than a little build up on the plates. I try not to charge mine over 40 amps to avoid warming up the battery. (that is with 4 golf cart batteries). I have solar, and if you are indicating that your whole RV will be in the garage, that is fine, and will keep the batteries in great shape if the factory converter stays plugged in all the time while in storage. Just check the battery water level every 4-6 weeks, until you can determine how quickly you will need to add water to them. At my work, the golf carts are serviced about every 8 weeks, and the 8 batteries use about 1 gallon of water for each golf cart. We have 5 golf carts at the large retirement center where I work.I have a motorhome with 4 batteries, 415 watt solar system, and I lived full time in it from 2005 - 2013. I have hydrocaps, so rarely need to refill the batteries. It changes the leaving hydrogen and oxygen from the battery gas back into water. If you become interested in solar power, click on my name, then 'view posts' put solar in the search line, and I have described my solar system install many times over the past 3 months. Even have pictures of the mounts that I made, and link to my favorite low cost solar panel supplier.Your RV will consume 35 amp hours daily to run just the CO meter, propane detector and refrigerator. Your old group 24 battery is only about 65 amp hours, so will run empty in a couple of days even without running ANY lights. The Trojan's are rated at 220 amp hours, and will serve you well. But after 4 days will require a lot of charging. This is where solar really helps. Even a pair of 140 watt panels will do a wonderful job. One to make up for the 35 amp hours used my the RV, and another to make power to use watching TV, run the furnace, ect.I figure that each of my 120 watt solar panels makes about 35 AH daily.My first set of trojan batteries lasted 13 years! Good luck,Fred.

The shumacher chargers seem to have the highest voltage of them all,....over 16 volts on my larger one, and well over 15 volts on the smallest maintainer ones.I try to avoid using the big 16v one, as no battery needs over 15 volts.If you want long battery life, and very little water consumption, connect to a PD converter, and forget it. If you got suckered into the hi voltage boxes, and believing you have to babysit and sleep w/ your batteries, good luck. 13 yrs out of a pair of batteries ??? Very possible, but you can bet they have never been fried w/ hi voltage boxes that were never designed to be battery chargers.

T-105 data sheet shows a charge voltage of a pair of 6V's should be 14.8 V. Float is 13.2 V and Equalize is 15.5 V.

Charging voltage for T-105s | Good Sam Community

33 Replies

Golden_HVAC
Explorer
Oct 27, 2015
I hope that you are not thinking about removing the battery and storing it in your garage between trips. That is not a requirement for long battery life. Certainly do not overcharge them, as melted battery plates are worse for battery life than a little build up on the plates. I try not to charge mine over 40 amps to avoid warming up the battery. (that is with 4 golf cart batteries).

I have solar, and if you are indicating that your whole RV will be in the garage, that is fine, and will keep the batteries in great shape if the factory converter stays plugged in all the time while in storage. Just check the battery water level every 4-6 weeks, until you can determine how quickly you will need to add water to them. At my work, the golf carts are serviced about every 8 weeks, and the 8 batteries use about 1 gallon of water for each golf cart. We have 5 golf carts at the large retirement center where I work.

I have a motorhome with 4 batteries, 415 watt solar system, and I lived full time in it from 2005 - 2013. I have hydrocaps, so rarely need to refill the batteries. It changes the leaving hydrogen and oxygen from the battery gas back into water.

If you become interested in solar power, click on my name, then 'view posts' put solar in the search line, and I have described my solar system install many times over the past 3 months. Even have pictures of the mounts that I made, and link to my favorite low cost solar panel supplier.

Your RV will consume 35 amp hours daily to run just the CO meter, propane detector and refrigerator. Your old group 24 battery is only about 65 amp hours, so will run empty in a couple of days even without running ANY lights. The Trojan's are rated at 220 amp hours, and will serve you well. But after 4 days will require a lot of charging. This is where solar really helps. Even a pair of 140 watt panels will do a wonderful job. One to make up for the 35 amp hours used my the RV, and another to make power to use watching TV, run the furnace, ect.

I figure that each of my 120 watt solar panels makes about 35 AH daily.

My first set of trojan batteries lasted 13 years!

Good luck,

Fred.
RDMueller
Explorer
Oct 27, 2015
rjxj wrote:
I have a mega and a mean well. Do it right the first time and get the mean well. Get the model that has a range of something like 13.5 to 17. It will give you the ability to equalize and let the converter do the float. OR just use a progressive dynamics converter for the basics and go solar. :)

Good to know, thanks! As far as PD and solar, all of this is happening in my garage now. I plan to always store and charge them in the garage as well.
azrving
Explorer
Oct 27, 2015
I have a mega and a mean well. Do it right the first time and get the mean well. Get the model that has a range of something like 13.5 to 17. It will give you the ability to equalize and let the converter do the float. OR just use a progressive dynamics converter for the basics and go solar. :)

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Charging voltage for T-105s

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