Adding AGM to existing Trojan Flooded 12V

Solarbusting
Solarbusting Registered Users Posts: 1
after just buying a brand new Trojan SC200 12v flooded Battery for a 2010 Class C Motorhome I am thinking about adding an AGM battery - mostly because I don't have an addl. battery bay and probably would want to mount the battery "Maintenance free" underneath the chassis.

Setup:
- newer 2010 e-450 with onan 4000 generator
- charger: unknown brand - thinking about upgrading to a 60amp magnum or so to minimize generator run time
- 15A MPPT solar charger, currently set for flooded+equalize (which I could change…)

is it advisable at all to mix flooded and AGM?

Comments

  • Joe_B
    Joe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: Adding AGM to existing Trojan Flooded 12V
    is it advisable at all to mix flooded and AGM?

    The simple answer is no,, they have different charging parameters.
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Adding AGM to existing Trojan Flooded 12V

    Joe is right. They will not play well together and one, or both of them will suffer and be damaged as a result.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Adding AGM to existing Trojan Flooded 12V

    even if they were the same type of battery, it is not advisable to mix unlike battery capacities either. it should be the same battery and within about a year or so of age to each other if not abused or heavily used. my advice is another sc200 and find a way to properly mount them both together. do be sure that they are getting a proper charge too as trojan advises about a 10% charge rate for most of their flooded batteries, but there is some wiggle room to that.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Adding AGM to existing Trojan Flooded 12V
    niel wrote: »
    even if they were the same type of battery, it is not advisable to mix unlike battery capacities either. it should be the same battery and within about a year or so of age to each other if not abused or heavily used. my advice is another sc200 and find a way to properly mount them both together. do be sure that they are getting a proper charge too as trojan advises about a 10% charge rate for most of their flooded batteries, but there is some wiggle room to that.
    As you say, it's not even a good idea to mix batteries of the same type and capacity but of different ages. Their internal resistance changes over time and that affects the charging current as well.