The Trojans are supposed to be the better buy. I have the interstates for Costco and they require 15.3 volts at about 2-4 hours for an absorption charge
http://www.batteries-faq.com/activekb/questions.php?questionid=1.
The Trojans are 14.8 volts so if you don’t have the capability to vary the charge rate on your charger then you may want to get the Trojans.
My PowerMax Boondocker charger has a dial so I can pump in up to 15.3 volts constantly.
I think the next set of batteries will be Trojan T105s so I can reach an equalization charge rate.

Here’s a link to a lot of great information,
http://solarhomestead.com/energy-independence/batteries/

If you want to capture a lot of the information presented in links and other web pages I suggest a program called Snagit by Techsmith http://www.techsmith.com/snagit.html
I use it myself alot. What’s on a webpage today may not be there tomorrow so get it while you can.

• This reply was modified 9 years, 10 months ago by RBuzz.

RV HOUSE BATTERIES

Here’s the deal in my opinion. An RV may come equipped with or RV Joe will purchase a cheaper 12 Volt so called “RV/Marine” battery at Walmart, and while sure they will “work” they are at best a semi Deep Cycle NOT a full true Deep Cycle battery such as a 6 volt Golf Cart Battery (Trojan, Sams Club, Interstate, Costco) that has thicker plates and is designed to better withstand deep discharges before recharging AND IS SUPERIOR FOR DRY CAMPING. The cheaper so called “RV/Marine” semi deep cycle battery is sort of a hybrid (auto starting battery and deep cycle battery) since it must have BOTH the capacity to start a large 200 HP marine engine and then perhaps power a trolling motor the rest of the day.

Of course, two of the 6 volt Deep Cycle Golf cart batteries must be connected in series to attain the necessary 12 volts, so room for mounting two batteries must be taken into consideration.

When batteries are connected in series, the voltage is additive (6 + 6 = 12) while the available Amps or Amp Hours (a measure of stored energy) is NOT. If you need more stored energy, when batteries are connected in parallel, voltage is NOT additive, but Amps and Amp Hours (stored energy) IS additive.

True Deep Cycle Golf Cart batteries are rated for so many “Life Cycles” (discharge and recharge) so if they are kept better charged (Solar or Charger or Engines Alternator) you’re NOT using up a “Life Cycle”. Its best to NOT let a battery become discharged more then 50% of its rated capacity (I don’t like to go more then 30%), IE a fully charged 12.6 volt series pair of 225 Amp Hour Trojan T-105’s shouldn’t be used for more then 112.5 Amp Hours (around 12.0 volts for two in series) before its fully recharged. To extend battery life a so called “Smart Charger” which may have 3 or 4 stages (Bulk, Absorption, Float, 4th Equalize) is far superior to the old style cheap noisy humming buzzing high heat Converter/Chargers which function more like a constant 13.4 to 13.6 voltage source.

So, if you’re into serious long term dry camping I suggest you invest in true Deep Cycle Golf Cart batteries versus cheaper RV/Marine batteries and use a so called “Smart” 3/4 Stage Charger or Solar Panels with a “Smart” Solar Charge Controller to keep the batteries charged as best possible to extend their life by NOT using up too many of their finite number of “Life Cycles”

John T in Indiana
Retired Electrical Engineer
RV user over 40 years
29 Ft Class C
470 Rooftop mounted Solar Watts (Two 235 Watt, 24/30 volt panels in parallel)
Four Trojan T-105’s in Series/Parallel for 450 Amp Hours of stored energy
2000 Watt Pure Sine Wave (PSW) Inverter
4 KW Genset