newbie battery and electrical question

full_mosey wrote:

fttang wrote:

full_mosey wrote:


Two 100AH 12V AGMs from Sams Club will yield 200AHs for $360(2 x $180), or about half the cost.

AGMs do benefit from a charger that monitors the battery temperature. This precludes the use of inappropriate high Voltages which may harm the AGM.

Look at the Parallax Powermode charger for around $175.

HTH;
John

actually the lifeline is rated at 220ah each for ~$290,
but as i was browsing, i found the trojan t105 flooded deep cycle,
there are quite some good words about them, the best part is they are 225ah and $140 each.
since there isn't really a capacity or performance difference with agm and flooded, i may go with flooded after all.

for the charger part, i always thought agm needs special charger, since starting batteries are also flooded and not stage charged.
so you are saying if i get agm i can wire them to the starting battery simply using an isolator and let the alternator charge it, but if i get flooded i will need stage charger?

I believe the Lifeline you cite is a 6V battery at 220AHs. When combined into a 12V bank, you get 220AHs at a cost of double $300, or $600. The pair of 12Vs I cited will yield 200AHs for $360 which is nearly half the cost. Two T-105s will cost $280 which will save you only $80 on purchase cost. Be sure you understand completely the care and feeding of deep cycle T-105s. Other posters may wish to help you with the charging requirements for deep cycle flooded batteries.

AGMs are drop in replacements for starting batteries. Therefore, yes, AGMs can be charged by any regular alternator or automotive charger. Your T-105s may require special chargers with features for stirring the acid. Again, be sure you have this info beforehand so you can analyze the comparitive costs to buy and maintain deep cycle batteries.

If you plan to charge/use house and starting batteries in parallel, it will be better to consider an all AGM setup.

HTH;
John