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bzp's avatar
bzp
Explorer
Sep 12, 2018

Converter charger upgrade?

Hi everyone,
I have a 2004 Winnebago Journey motorhome and I recently upgraded my house batteries to three 12V AGM batteries. The new batteries work great but my current converter charger is not capable of charging them in a reasonable time. My current charger is a Parallax 13.6 VDC, 55 amp model 7455 that was original equipment on my coach. The charger seems to be working correctly but it appears to have two deficiencies:
1) It does not have adequate charging voltage (especially in the initial charging stage. 2) It automatically reduces charging current long before the batteries have a full charge.


I am considering buying one of the new 55 Amp multi-stage chargers that charge with high voltage initially and turn down as appropriate as the batteries reach full charge. I would like to use my current wiring which is 6 AWG and I believe the max rated current through that cable is 60 amps. Therefore, I think I am limited to no more than a 55 amp charger.


Am I on the right track for this do-it yourself project? Will the exisiting 12VDC components in my 2004 vintage coach handle 14.7 VDC during the high voltage charge stage? Should I bite the bullit and change out the wiring to allow a higher amp charger (my batteries can handle up to 190 amps)?


Your thoughts and Wisedom will be greatly appreciated.


BZP

11 Replies

  • I have done this before on a prior RV. You may want to consider upgrading the wiring if possible. Depending on the wire path it may be more difficult. I purchased a $50 60,000 psi wire crimping tool at Harbor Freight Tools. Yes you can simply install a 60 amp 3 (or 4) stage converter however depending on your usage you may be disappointed. I have a 90 amp version I installed in my cargo trailer. It sounds like a lot but it isn’t. 100 amps at 12 v is only 1200 watts. At 120 v that’s only 10 amps! I’m assuming that your coach doesn’t have any inverter. If it does or you plan on adding one a small converter won’t work.