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defrost's avatar
defrost
Explorer
Jul 14, 2020

Replacing Flooded Lead Acid with AGM - new charge converter?

Hi - looking for some advice/help. I am replacing my flooded lead acid batteries with new AGM batteries. The trailer is a 2018 Keystone Carbon 38'. Do I need to get a different charge converter to safely charge the AGMs or will the stock converter do the job without issue?
  • It would be helpful to know what model charger you have. Most relatively new ones have capability to switch battery type. In my opinion, most Wet cell chargers will not be unsafe to charge AGM types....but the slight different charge algorythems may shorten the life of the AGM batteries....
  • Is the concern with the existing converter that it would charge at too low of a voltage?
  • defrost wrote:
    Is the concern with the existing converter that it would charge at too low of a voltage?
    Yes. A low voltage slow charge will chronically undercharge an AGM and result in premature loss of capacity. WFCO is notorious for just charging at 13.6 even when described as a 3-stage converter. Still need to confirm what you have.
  • Lwiddis wrote:
    defrost will get back to us.

    Dug through the rig and found the converter hiding behind a panel, lots of fun :) It is a WFCP 75 Amp WF-9875. I am going to replace it with Progressive Dynamics PD9270V. Thanks for your help!
  • According to the product description of his current charger converter, it does have Bulk, Absorb, and Float stages of battery charging. It also has battery type selection for wet, AGM, and Gel type batteries. It appears that he does not need to replace his existing charge converter.
  • Ed_Gee wrote:
    According to the product description of his current charger converter, it does have Bulk, Absorb, and Float stages of battery charging. It also has battery type selection for wet, AGM, and Gel type batteries. It appears that he does not need to replace his existing charge converter.
    Maybe. There would be nothing wrong with giving WFCO a test run. First trip let the battery get down to 12.2 volts and fire up the generator. Voltage should steadily climb to 14.2+ volts over 20 to 60 minutes. Otherwise time for a converter swap. WFCO is notorious for just charging at 13.6 volts regardless of the description in the operating manual.

    I recommend this test for anyone that has a WFCO and charges the battery using a generator.
  • Ed_Gee wrote:
    According to the product description of his current charger converter, it does have Bulk, Absorb, and Float stages of battery charging. It also has battery type selection for wet, AGM, and Gel type batteries. It appears that he does not need to replace his existing charge converter.

    I'll agree that the documentation does say that. However, the WFCO is notorious for never going into bulk mode. He needs one that actually does what the documentation SAYS it does.

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