Battery Upgrade

[peirek]

First let me set the stage. We boondock 1-2 weeks a year. The rest of the time the trailer is plugged into shore power either in storage or at campground with hookups. We have one house GP27 wet cell battery in a rear storage compartment. The battery is in a sealed box and is vented bottom and top. The house battery is approximately 8' from charger (WFCO WF-8935AN-P) connected with 6AWG wire (I am estimating ~10' of wire). I have been taking a second deep cycle battery and connecting to front vehicle connector. This is approximately 20' from charger. I know this is not at all efficient and is mildly effective, but it has served us ok. We run the genny (Honda EU2000) for ~4 hours a day which gets the batteries back up but not fully charged.

I would like to add a second battery to the rear storage compartment but have to consider venting etc. I am leaning towards using two AGMs (6V or 12V?) so as to not worry about gassing and venting. The compartment is big enough to contain both batteries and it will still have a vent top and bottom.

I am looking for guidance on AGM batteries (6V or 12V) and brand. I have learned the Trojans are the best but are they needed for my situation (1-2 wks a year)? I suspect upgrades to the charger will be in order so would like opinions on that. I believe Progressive Dynamics is the preferred brand. I also believe the 14.8 is recommended for AGMs. Is the 6AWG sufficient for a 45A upgrade?

Thank you for your suggestions, directions, and opinions in advance.

[peirek]

wa8yxm wrote:
FIrst Wire Size.. Is determined by the maximum output of your converter. How many batteries does not matter. Converter size does. 6 AWG is about 30 amps.

The 35A charger is approximately matched to the wire.

Second: Battery/Converter size ratio affects recharge time in the BULK phase.
Understood

THird AGM batteries are VERY EXPENSIVE compaired to say a pair of GC-2 at Sam's or Costco (90 each ish)
Understood but I would need to deal with venting of the second battery which is no small issue.

Finally Your G-27's are MARINE/deep cycle more than likely really a starting battery you'd be better off with GOLF CAR (GC) batteries.

I mislead. I have GP24 battery, not 27. GC would be best. Do they make an AGM GC?

[peirek]

time2roll wrote:
Does the WFCO ever go above 14.0 volts? 250 watts solar and the existing battery(s) would do a lot better. Maybe even leave the generator at home.

Lifeline (AGM) specs say charge at 14.4 volts. Trojan T-105 (flooded) says 14.8 volts.
Match the voltage to the actual batteries you get for best results.
Either way you probably need to replace the WFCO if using the generator.

The WFCO does not go to 14.4. It has 3 modes:
Absorption mode: 13.6v
Bulk mode: 13.2v
Float mode: If it detects usage jumps to Bulk mode for 4 hours.

Agree with matching batteries to converter. Not terribly interested in installing solar, at least for now. We just don't boon dock enough and normally in pretty shady spots.

[pianotuna]

Hi,

How deep are your pockets?

I would add solar 400 to 600 watts.

If you do move to the "new" location for the battery bank, make sure it can support the weight. I had a support welded under my "second" battery bank and added a layer of 3/4 inch plywood.

[wa8yxm]

FIrst Wire Size.. Is determined by the maximum output of your converter. How many batteries does not matter. Converter size does. 6 AWG is about 30 amps.

Second: Battery/Converter size ration affects recharge time in the BULK phase.

THird AGM batteries are VERY EXPENSIVE compaired to say a pair of GC-2 at Sam's or Costco (90 each ish)

Finally Your G-27's are MARINE/deep cycle more than likely really a starting battery you'd be better off with GOLF CAR (GC) batteries.

[peirek]

2oldman wrote:
Lifeline batteries are excellent.

And further proof that there are other options beyond Trojan....

[time2roll]

Does the WFCO ever go above 14.0 volts? 250 watts solar and the existing battery(s) would do a lot better. Maybe even leave the generator at home.

Lifeline (AGM) specs say charge at 14.4 volts. Trojan T-105 (flooded) says 14.8 volts.
Match the voltage to the actual batteries you get for best results.
Either way you probably need to replace the WFCO if using the generator.

[peirek]

SoundGuy wrote:

peirek wrote:
I am looking for guidance on AGM batteries (6V or 12V) and brand. I have learned the Trojans are the best but are they needed for my situation (1-2 wks a year)? I suspect upgrades to the charger will be in order so would like opinions on that. I believe Progressive Dynamics is the preferred brand. I also believe the 14.8 is recommended for AGMs. Is the 6AWG sufficient for a 45A upgrade?

You've learned Trojans are "the best" eh? :R We too only dry camp infrequently and for my use a G31 Deka AGM serves my purposes fine. At times when I might want to power my 1000 watt PSW inverter I merely load support it with my truck and it works just fine for running our toaster & coffee maker, avoiding the need for a second battery I'd otherwise have no need for. East Penn is very specific about requiring temperature compensated charging but nominally their Deka brand AGMs want to see a 14.4 volt bulk charge voltage, no higher. You could replace your converter but I chose to simply turn my WFCO off and instead use a stand alone charger capable of the required 14.4 volt bulk charge voltage and located it next to the battery so voltage drop due to cable gauge is a non-issue.

Hey Soundguy thank you for your response. I think I misspoke. It seems a lot of opinions favor the Trojans but certainly not all. I'll leave it at that.

So you are using a single Deka G31 (I assume deep cycle) and have no issues boon docking for a week or two? How often and long do you run the genny?
I would prefer to not have an separate charger to carry along and manage but it is an option. I guess my preference is a simple plug and play.
Thanks for the note on the 14.4V maximum.

[SoundGuy]

peirek wrote:
I am looking for guidance on AGM batteries (6V or 12V) and brand. I have learned the Trojans are the best but are they needed for my situation (1-2 wks a year)? I suspect upgrades to the charger will be in order so would like opinions on that. I believe Progressive Dynamics is the preferred brand. I also believe the 14.8 is recommended for AGMs. Is the 6AWG sufficient for a 45A upgrade?

You've learned Trojans are "the best" eh? :R We too only dry camp infrequently and for my use a G31 Deka AGM serves my purposes fine. At times when I might want to power my 1000 watt PSW inverter I merely load support it with my truck and it works just fine for running our toaster & coffee maker, avoiding the need for a second battery I'd otherwise have no need for. East Penn is very specific about requiring temperature compensated charging but nominally their Deka brand AGMs want to see a 14.4 volt bulk charge voltage, no higher. You could replace your converter but I chose to simply turn my WFCO off and instead use a stand alone charger capable of the required 14.4 volt bulk charge voltage and located it next to the battery so voltage drop due to cable gauge is a non-issue.

[2oldman]

Lifeline batteries are excellent.

[Lwiddis]

Four hours of generator charging per day? That’s no fun. Consider solar..I’ve been floating for the last 4+ hours. No gasoline, no noise.