AGM battery charging

[seeverest]

I have a 2016 Rockwood HW316TH that came with a standard deep cycle battery. This battery is now junk. Can I replace the battery with an AGM and still use the internal charging system of the camper? Thanks

[babock]

You can still use the same charger. However, I suggest getting rid of the stock(most likely WFCO) charger and upgrade to a Progressive Dynamics.

[TitanMike]

Originally Posted by babock

You can still use the same charger. However, I suggest getting rid of the stock(most likely WFCO) charger and upgrade to a Progressive Dynamics.

If using a PD with Charge wizard it would be a good idea to avoid forcing a "Boost" charge and just let the charger control charge rate. AGM's don't like to be charged at high rates that generate hydrogen and Oxygen gases faster than it's internal design can convert back to water. Lost water in an AGM can't be replaced.

Surprisingly, Optima recommends a relatively low charge rate (10-15 amp) for their AGM's and I'm sure other AGM's are somewhat the same.

[seeverest]

Originally Posted by TitanMike

If using a PD with Charge wizard it would be a good idea to avoid forcing a "Boost" charge and just let the charger control charge rate. AGM's don't like to be charged at high rates that generate hydrogen and Oxygen gases faster than it's internal design can convert back to water. Lost water in an AGM can't be replaced.



Surprisingly, Optima recommends a relatively low charge rate (10-15 amp) for their AGM's and I'm sure other AGM's are somewhat the same.

Awesome thank you I will look into upgrading chargers.

[babock]

Originally Posted by TitanMike

If using a PD with Charge wizard it would be a good idea to avoid forcing a "Boost" charge and just let the charger control charge rate. AGM's don't like to be charged at high rates that generate hydrogen and Oxygen gases faster than it's internal design can convert back to water. Lost water in an AGM can't be replaced.

Surprisingly, Optima recommends a relatively low charge rate (10-15 amp) for their AGM's and I'm sure other AGM's are somewhat the same.

Actually it's the opposite. For my boat's Oddysey batteries I had to buy a charger with more current. Lifeline AGMs are just like Oddysey and require a 0.2C minimum current for their batteries and they encourage you to charge greater than that.

Page 20
http://2cw8eb1vmmgg3g5i7jzt6upo.wpen...cal-Manual.pdf

Speaking of Optima, that would be my very last choice of an AGM battery. Many better choices out there.

[pgandw]

Originally Posted by seeverest

Awesome thank you I will look into upgrading chargers.

You don't need to upgrade if your WFCO converter is working correctly. The most common problem with a WFCO converter is that it never shifts modes when it is supposed to.

According to factory specs, the WFCO is supposed to shift to trickle mode after 44 hours in normal mode with no significant change in load. Normal mode is 13.7V, trickle mode is 13.2V.

In both my Forest River A-frames, the WFCO would never go to trickle mode, even after 2 weeks in normal mode. Because of that, I replaced the WFCO 8735P converters with PD 4135 converters.

The WFCO 8735P does not have an easily replaceable converter module. Replacement means replacing the entire panel along with the converter.

The PD 4135 is pretty much a "drop-in" replacement. However, you have to move all the AC and DC circuits over to the new panel, and the circuit breakers and fuses. Depending on how much re-wiring you want to do (I didn't like the way FR did a lot of their wiring), replacing the converter is a 3-8 hour job.

I am glad I did the replacement. I don't have to worry about whether the converter is taking care of my batteries or not. Just check the battery water level every few months. And I fixed a lot of the wire nut strings while I was at it.

hope this helps
Fred W
2019 Flagstaff T21TBHW A-frame with 2 Costco Interstate GC-2 batteries

[babock]

The problem with WFCOs is that they don't spend much or any time in bulk mode and don't get up into the mid 14V ranges EVER. You are asking for long recharge times and sulfation because of that.

[Cypressloser]

Originally Posted by babock

The problem with WFCOs is that they don't spend much or any time in bulk mode and don't get up into the mid 14V ranges EVER. You are asking for long recharge times and sulfation because of that.

Correct!
When I had my Xantrex charger in for repairs last winter and had to use the WFCO for a few weeks the difference was very noticeable. AGM batteries reach a 100% SOC at 13 Volt unlike standard flooded lead acid batteries that are charged to 12.6 Volt.

I also suggest to the OP to invest in a charger capable of adjusting the rate of charge based on battery temperature.