Type of battery charger to buy

[Ho jo]

I didn't realize you had a fifth wheel.
My GC batteries have been in series parallel for 3 years.
what size is you battery compartment?
A friend of mine built his box with plywood.
and vented it with 1.5 pvc
I wouldn't consider metal for a battery box.

[chrisski]

I didn't realize you had a fifth wheel.
My GC batteries have been in series parallel for 3 years.
what size is you battery compartment?
A friend of mine built his box with plywood.
and vented it with 1.5 pvc
I wouldn't consider metal for a battery box.

I appreciate the size of the PVC pipe. I have no idea of how big to make this vent. If I go with lead acid batteries instead of AGM, I was thinking of using the current 2" hose that's already venting my single lead acid battery, by putting each of the four GC2 battery in a Battery box, drill a 2" hole in the top of the battery box, and joining the four hoses to vent out the single 2" outlet that is already drilled in the side of the RV. I will just be sure that hose runs up so any gasses won't pool in there. I might even use a 2" PVC pipe.

Luckily where I will put the battery and where the one battery I have now is not constrained by space. Basically the current battery compartment is in the large forward storage compartment that runs the width of the RV and under the bedroom, so probably 10 feet wide across the RV, 5 feet long, and three feet tall. If I feel I can properly vent flooded lead acid batteries there, that is where they will go.

[Ho jo]

I would also put a vent hole in the bottom of the box (piped down to the outside also) so fresh air can enter, as to not create a vaccuum as the gasses exit.

[Mike90250]

What I'd do to that fwd storage.
(Does it have a slide out tray or drawer ? )

I'd paint the sides and top with asphalt or pickup bed liner paint, Seal it real well, so it's airtight. (caulk it the week before)
Then simply use three or four, 2" round "Foundation Vent" from the hardware store, as high as possible, on either end they have bug screen and rain louvers on them
Hydrogen wants to get out, and a couple vents will do the job.
Even if you used AGM, you have to allow for venting hydrogen at their end of life.

Just turn the whole compartment into a battery box.

Put a sacrificial strip of 1/4" plywood covering the whole bottom to soak up any acid spills

[chrisski]

My NOCO Genius G4 4 charger, 4 amps, does not seem to be charging my newly delivered 229 AH at the 20 hour rate 6V batteries. When I signed for the batteries, there was no visible damage, the voltage was 6.1 Volts each, and they had enough water in them.

I hooked the charger up and read underneath 25%, and after 24 hours of charging read between 25% and 50%, and another 12 hours did not bring the batteries above the 50% mark.

I'm going to call the seller up on Monday, but is it common to have batteries delivered to you that need a deep charge from the start? I've always put my newly purchased 12 VDC RV battery on a .75 amp charger and it's topped overnight.

[Mike90250]

New Batteries often need a commissioning charge and a couple medium deep cycle to get the plates activated. I would read up on what's required for your models.

However, a slow trickle charge, on a new battery, won't hurt, even if the plates are still being formed. But when you start cycling them, be prepared to recharge in 24 hours

[chrisski]

New Batteries often need a commissioning charge and a couple medium deep cycle to get the plates activated. I would read up on what's required for your models.

However, a slow trickle charge, on a new battery, won't hurt, even if the plates are still being formed. But when you start cycling them, be prepared to recharge in 24 hours

I did find some recommendations from the manufacturer:

Max Current: 13% of C20
Absorption: Once Absorption voltage is reached, maintain: 7.35 VDC
Constant Current: Once at that voltage current falls to 1% - 3% C20 (2.3 Amps to 6.9 Amps), maintain a charge of 1% - 3% C20 (2.3 Amps to 6.9 Amps).
Float Charge: 6.75 Volts.

Most Chargers have an automated charging, so I don't know how close it is to that. I guess its off to the manufacturer to see if they can find a 30 amp 6V charger that follows that profile.

[chrisski]

I got a reply from the Battery Manufacturer and for my 225 AH at the 20 hour rate 6V Flooded Lead Acid Batteries, he recommended a NOCO Genius G26000 12V/24V 26 Amp Pro-Series Battery Charger and Maintainer. Since its a 12 Volt Charger, he said to wire the batteries in Series when Charging. He also said to charge on the AGM mode.

It's a 26 AMP charger, so that falls in the 23-30 amp recommended charge range, and I'll just have to trust his recommendation about going in series to charge and using the AGM mode.

I found it extremely difficult to find a charger that matched the 10% of the C20 rate. A lot of the 30 amp chargers I saw, those were boost modes, and the owners manual did not say how long they were activated for after you pressed the button, and others had the 30 amps on a timer, and others had the 30 amp mode available for 12 VDC, but not 6 VDC.

[Ho jo]

5 year warranty for $230.
I like the fact that it charges multiple voltages.
12 volt for now. Or if you decide to go 24 volts later you don't have to change chargers.
my Iota is half the price but only 2 year warranty. And 12 volt only.

[chrisski]

5 year warranty for $230.
I like the fact that it charges multiple voltages.
12 volt for now. Or if you decide to go 24 volts later you don't have to change chargers.
my Iota is half the price but only 2 year warranty. And 12 volt only.

This charger did not even show up on my Amazon searches, E-Bay Searches, or looking at the company websites; either that or it was buried on the 10th page, or I just browsed over it. The place I bought the batteries from could not recommend a charger, although they gave me three brands to check. Until the tech E-Mailed me this morning, I was looking at a Clore 6V/12V 2- amp charger, which missed the manufacture's 23 amp lower amp limit by 3 amps. Not sure how much of a difference that would have made.

I am really surprised that the battery manufacturers don't each carry a wall plug charger for batteries at their recommended charge rates. Out of all the manufacturer websites I went to when looking for batteries, I only saw VMaxx had chargers for their batteries, but not the larger ones, and 12V, not 6V. Interstate sold some, but not for large deep cycle batteries.

Depending on how this RV setup works when I build it, I've got an idea how I would get to 24 volts, so there is expansion. I'd string another couple strings of panel into the inverter, and then figure out how to run the 12 volts that the RV uses.

[Ho jo]

I used a a day green 20 amp 24-12 convertor.
won on ebay auction 5 bucks.
My 30 amp mppt controller was maxed with 500 watts @ 12 volts. (2 gc.)
I was able to add 500 more watts with the same controller@24. With 4 batteries in series. Double charging and capacity.

In my rv 12 volt loads are minimal 100-250 daily wh.
led lights, stove vent, water pump, fridge lp solenoid etc. 11 or12 peak amps.
The real power usage came from using the inverter. 32 led tv box fan.
inverter efficiency and tare losses being on 24-7. ~1 kwh daily.|

[chrisski]

I used a a day green 20 amp 24-12 convertor.
won on ebay auction 5 bucks.
My 30 amp mppt controller was maxed with 500 watts @ 12 volts. (2 gc.)
I was able to add 500 more watts with the same controller@24. With 4 batteries in series. Double charging and capacity.

In my rv 12 volt loads are minimal 100-250 daily wh.
led lights, stove vent, water pump, fridge lp solenoid etc. 11 or12 peak amps.
The real power usage came from using the inverter. 32 led tv box fan.
inverter efficiency and tare losses being on 24-7. ~1 kwh daily.|

Kind of interested in your LP consumption. On a cool day, about 70 F, with nights into the low 40’s, I used about 1 gallon of LP over three days, including heat and Fridge. Still trying to gauge how much LP we use on the trips. The Colder trips can be up to 1 gallon a day, where nightime temps dip below freezing, and that last one is just for heat.

[Ho jo]

Speaking from my limited freezing nightly consumption. In my 34 ft TT.
This varies with temp settings. So it's not a one size fits all. Usage will vary.
At 30f not opening out side doors my 35000 btu heater runs 5 minutes then off for 10. So a 33% duty cycle. Longer run time if its windy.
a gal of lp has ~91500 btu. So about 8 hours per gal.
The heater blower when running 10.5 amps 130 watts.

A 20 lp 4.7 gal tank at 60f nights 80f days
Worst case in my usage. will last 3 weeks for refrigerator less if fridge is full
more if adding Warm foods.
We don't hold the door open.

[chrisski]

I have the batteries hooked to the 4 amp charger, and I was surprised to hear them off gas as they get above 75% charged. I guess the hydrogen bubbling is not just theoretical. Certainly more than I expected. I will certainly make sure the venting system is good when I get them moved into the RV.

[Mike90250]

I have the batteries hooked to the 4 amp charger, and I was surprised to hear them off gas as they get above 75% charged. I guess the hydrogen bubbling is not just theoretical. Certainly more than I expected. I will certainly make sure the venting system is good when I get them moved into the RV.

If these are AGM batteries, I urge caution, as you should not be hearing them gas.

Well, maybe you will hear the gas bubbles as they charge, but the re-combiners should catalyze it back to distilled water, and drip back into the cells, Any venting gas is wrong.