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stormmolly · 11-11-2016, 01:30 PM

I currently have a 12 volt battery which is now deader than a door nail. Research and recommendations are saying move to two six volt batteries. Any suggestions on brands? Opinions on making this switch are also invited as two batteries cost more than one

dons2346 · 11-11-2016, 01:31 PM

Trojan T105 or 125

bluepill · 11-11-2016, 01:40 PM

Quote:

Originally Posted by dons2346

Trojan T105 or 125

This^^

If you have the space for larger batteries and really need the capacity, go for it. Remember that the charging time is longer as you add amp. hour capacity.

wa8yxm · 11-11-2016, 04:34 PM

BEST (and most expensive) Trojan
Best bang for the BUCK, Sam's Club (If that is you have a membership)
What I am using now DEKA G-20's

As of when I got 'em (2013) Deka's were 100% Made in the USA from products sourced in the USA. not many can make that claim.

nothermark · 11-11-2016, 08:59 PM

It depends on what you have for an RV. If you have the room and weight carrying capacity then you can go to some big batteries like the T105. If you do not there are smaller batteries available that will fit.

If you have a choice between two 6 Volt in series or two 12 V in parallel in the same case size the 6 V will have more capacity.

My real point is that given unlimited space and deep pockets batteries like the T105 are probably the best choices in wet cells. Given the confined spaces and shallow pockets most of us have there are reasonable compromises that will get most folks through the night. That is why I have two 12 V group whatevers from Sam's Club. They make it through the night then the genset does it's job.

chboone · 11-11-2016, 09:27 PM

My local Costco has Interstate GC-2 6V for $83.99. I have six of them for about 2 years so far they have served me will. I agree Trojans are very good batteries. You need to decide if the difference in cost is worth it to you.

azchoco · 11-11-2016, 10:29 PM

I converted my 12v marine battery to two T105 Trojan batteries in series expecting a longer discharge time. I thought it doubled the amps. I understand all you double is the voltage not the amps (2 x 6 = 12). To double the amps, you need to put two 12v batteries in parallel which is still 12v. This delivers 12v with double the amps. T105's for me ran down fast for some reason. I charged them up with either my generator connected to my camper or with a 85 watt solar panel.

shovelhead86 · 11-12-2016, 06:01 AM

Quote:

Originally Posted by stormmolly

I currently have a 12 volt battery which is now deader than a door nail. Research and recommendations are saying move to two six volt batteries. Any suggestions on brands? Opinions on making this switch are also invited as two batteries cost more than one

My wife and I were just talking about this. Neither of us have ever seen a live door nail.
how would one determine if one was alive or dad?

I have had 2 12 volt deep cycle marine batteries in for about 5 years now. I know I will have to replace them soon but they are still working fine. We do not dry camp much. But we are fulltime so occasionally we do.

nothermark · 11-12-2016, 06:23 AM

Quote:

Originally Posted by azchoco

I converted my 12v marine battery to two T105 Trojan batteries in series expecting a longer discharge time. I thought it doubled the amps. I understand all you double is the voltage not the amps (2 x 6 = 12). To double the amps, you need to put two 12v batteries in parallel which is still 12v. This delivers 12v with double the amps. T105's for me ran down fast for some reason. I charged them up with either my generator connected to my camper or with a 85 watt solar panel.

The general theory is a 6 V or 3 cell battery has bigger individual cells than a 12 V battery or 6 cell battery in the same case size. Fewer separator walls so room for more plates.

The problem with all batteries is it takes time as well as available current to charge them. Most folks short cycle their generator run times compared to what the recommendations are to fully charge the battery.
When charging current is split between the battery and the other 12 VDC loads. If one significantly upsizes battery capacity without changing the converter then the run time has to be increased even more to put back the Amp/hours used. Part of how much more is what else is drawing power while charging. An 85 W panel puts out around 7 Amps so would take a long time to top off a T105 string. Maybe longer than you had good daylight.

chboone · 11-12-2016, 07:57 PM

Quote:

Originally Posted by azchoco

I converted my 12v marine battery to two T105 Trojan batteries in series expecting a longer discharge time. I thought it doubled the amps. I understand all you double is the voltage not the amps (2 x 6 = 12). To double the amps, you need to put two 12v batteries in parallel which is still 12v. This delivers 12v with double the amps. T105's for me ran down fast for some reason. I charged them up with either my generator connected to my camper or with a 85 watt solar panel.

Marine batteries are not True Deep Cycle Batteries and will never provide the same amount of amp hrs that a True Deep Cycle battery such the Trojans or any other Golf Cart battery will. Do you have your solar charge controller set to 14.8 V that is the spec Trojan requires for their batteries for bulk and absorption charging. float is 13.2 V. If your solar controller and battery charger have temperature compensation use it. How many hours do you run you generator to fully charge the batteries? I have 420 Amps of solar and have my controller set at 14.7 bulk and absorption and 13.2 float. I have interstate GC-2 6V batteries that's the reason for 14.7 V setting.

edatlanta · 11-14-2016, 03:48 AM

I converted my new in 8-2010 5'er from a single 12v battery to two T-105's within the first few weeks of full timing. I don't boondock a lot, but some at races, etc. With any wet cell battery don't forget to check the water (and distilled only) level. I check mine in the spring and again in the fall after summers on the Florida gulf coast. They both need water and about the same amount per cell. I have never had one low enough to expose the top of the plates, but have been close a time or two.

After a bit over 6 years of full time use the Trojan's are holding up well. I spent 5 days at Talladega a couple of weeks ago and only ran the generator a bit in the mornings for coffee and they held up well.

I did just add water to both a couple of days ago so I'm good until spring.

tmw188 · 11-14-2016, 04:14 AM

That seems like a pretty long interval to me. I check mine once a month, probably because they are maintained with a solar panel and easy to get to and fill using the ProFill system. I guess if you don't have them on a maintainer and your idle most of the time with no load that fill interval might work for you but I would check them a little more often.

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IC2 · 11-14-2016, 05:10 AM

The Trojan batteries are fine - but do you really need a couple of big ones such as those are taking up valuable storage space. If you do some to lots of dry camping, for sure those are the best way to go. If you are usually tethered to a CGs 120VAC service - an expense you really don't need as it entails not only the batteries but a box with a drain and separate out gas vent too. If the existing battery that has died is the usual stealership's Gr24 Interstate, you can move up to a G27, or 29 or 31. We moved to a Gr 31. It will do a complete set up - 4 slides, landing gear and rear stabilizers, and at have least enough 'life' left for lights and roof vents overnight plus a hookup the next morning and probably more if we wanted to try to go further.

Of course, this is only my opinion tho based on long term RV ownership

ewacowboy · 11-14-2016, 08:02 AM

Quote:

Originally Posted by stormmolly

I currently have a 12 volt battery which is now deader than a door nail. Research and recommendations are saying move to two six volt batteries. Any suggestions on brands? Opinions on making this switch are also invited as two batteries cost more than one

Your question doesn't give enough information. You need to make choices based on how you use your coach. If all you want is 12 volt power to extend the slides and drop the jacks before you connect to shore power, then a single 12 volt will work just fine. If you need power for a couple of days without hookups, then moving to multiple batteries will be your best benefit. Also, if you have solar or are considering solar, then the 6 volt option is a must.

As far as types....if you purchase wet cell batteries then you will need to maintain the water level periodically. You don't want the water level to run low as that will kill your batteries faster than anything. If you want to install them and forget them, then an AGM style is your best bet.