We’ve been using “traction” batteries for years in our boats. Our experience is that these have the best ratio of cost/space/weight to USABLE amp hours available. The cells we use are typically guaranteed for 1500 80% cycles! In the marine field, assuming you equalize them periodically, they will last 15 to 20 years, and withstand a huge amount of punishment.
We’ve been buying these from Trojan Batteries for at least a decade. Now Trojan has sold this division, and the new owners are not interested in building the type of batteries which are useful to sailors. However, our friends at Trojan have put us in touch with SBS Batteries, and they are very much still in this business. For more information, visit their web site at http://www.sbsbattery.com . Or, in the US you can reach them at 262 703 5800, or by fax at 262 703 3073. The e-mail address is scottR@sbsbattery.com.
They have just made us a set of traction style batteries. We found them easy to deal with and very competitive on price.
To read an article about maintenance issues with traction batteries, click here.