full_mosey writes “
I am a little confused. I STFW and found a STANDBY AGM that has this in the specs.
Quote:
Can be used for more than 260 cycles at 100% discharge in
cycle service”Yeah, confusing, isn’t it?
Honestly, I would be very leery of the manufacturer overhyping or stretching the truth on this in order to gain sales. That 100% may actually be 20% DOD, in other words that battery will give X amount of life cycles using 100% of typical DOD (20%) for this type of battery.
Granted I am guessing on this a bit but I would really doubt that it would indeed not only survive a discharge to 10.8V (100% DOD) but give 260 cycles of that abuse. I could however expect 260 cycles at 20% DOD..
I found a nice description of how life cycles can be affected by how deep of a discharge the battery gets.
HERE“For a weekend camper, that is 260cycles/52weeks-per-year = 5 years of 100% discharge service.
Are you saying that if these AGMs are used at 30% discharge cycles that I would get less than 5 years of weekend service?”That would be correct IF the DOD is 20% for 260 cycles, the problem is the actual info may be “masked” by marketing double speak as you have found. From my own searching on this AGMs can have a range of 5%-60% DOD but typically 20%-50% DOD.
Many people seem to think AGMs are indestructible and should be used for ALL applications.
My gut feeling is that is not true, AGMs CAN be destroyed.
While AGMs can be an improvement for SOME applications they are often NOT ALWAYS the best choice for EVERY application.
With any battery, max life cycles depend on many conditions, how much DOD, how long the battery sits with a partial charge, what temperature and even how hard the battery is recharged at can make a dramatic difference with the life of a battery.
I get the feeling that people consider flooded batteries to be a hassle because they need some maintenance like water or cleaning the terminals. Watering can be made simple by adding a automatic water system or you can get caps which “recover” most of the boiled off water.
Properly sized battery bank for usage and charging conditions along with three stage charging reduces the water usage considerably.
As far as cleaning the terminals, I rarely need to clean battery terminals, I use a product called No-Alox, it is a light “grease” which is specifically designed for preventing corrosion of electrical terminations. Use it for all of my vehicles and any electrical connector which is exposed to outdoors, works like a charm…
If you want max life, then shallow discharges quickly followed by a full recharge (full recharge will be MORE Ahr than what was drawn) will do this for you FOR ANY BATTERY TYPE.
For some folks, they just like saying they have AGMs, I really don’t care if folks think I am in the stone age using flooded batteries. I got a lot more Ahr per $$ than what I would have gotten with AGMs and to me that’s what counts.
For the OP of this thread, I noticed that you mentioned in another thread that you don’t camp without shore power or boondock.
To me in spite of what many other posters have posted, it would be a complete waste of YOUR money to buy another AGM battery, period.
Your converter will supply 12V for lights, fridge, furnace while plugged into shore power.
While traveling your vehicle will supply 12V for those devices in your TC as long as it is plugged into the truck. The draw back however is if you stop for too long you may draw your truck battery down or if a relay is installed your TC won’t have power when engine in not running.
So, you could simply disconnect and remove the battery, insulate the wires and call it good or as I mentioned before you can by a special battery box which has a top cover that seals and a vent connection which vents via a hose to the outside.
VENTED BATTERY BOXThen you can get a low cost group 24 or group 27 flooded battery ($60-$70) which gives you some flexibility while you are traveling (40Ahr usable capacity). This allows you to stop anywhere for more than a hr or so and not worry about drawing your truck battery down.
You would still need to disconnect the battery during storage or since a group 24/27 battery is smaller take it with you and store at home periodically charging it.