LJD and others, Deep Cycle Battery Use

Yo, LJD and others, I know LJD has more experience then myself in the use of and charging Golf Cart Batteries so Im looking for experienced opinions. I have a new used RV and will be running four 6 volt Deep Cycle Flooded Golf Cart Batteries in series/paralell for my 12 volt coach power (lights, vent fans, inverter, etc). The RV has the run of the mill cheap not well regulated approx 30 amp 12 VAC/12 VDC Converter Charger WHICH I DONT WANT ANYWHERE NEAR MY NEW GOLF CART BATTERIES (it can overcharge and cook them).

I will be using a Xantrex Truecharge 2 40 amp smart three stage (Bulk/Absorption/Float plus Equalize when needed) regulated charger WHICH I WILL USE TO CHARGE AND MAINTAIN my batteries.

QUESTION

Of course, when I'm plugged into shore power I can use the cheapie converter/charger to power my internal 12 volt loads (Still NOT to charge my new golf cart batteries, ONLY the Xantrex will do that) buttttttttt that darn converter/charger is a noisy buzzing heat producing piece of crap.. Sooooooooooo if instead I keep all my 12 volt loads on the golf cart batteries 24/7 (NOT use the converter/charger at all) and all the time let the Xantrex keep them charged and floating as it automatically determines they need it, IS THAT GOING TO HARM THE LONGEVITY OF MY NEW BATTERIES.

For best battery life you think its best to keep the Xantrex on them 24/7 and use them to power my RV 12 volt loads all the time or use the buzzing cheapie converter/charger to power the RV (although the Xantrex will still be on them all the time I reckon, even if Im parked in an RV park for months at a time??)

My buddy has a Xantrex he keeps on his batteries all the time and if he looks at the charge monitor its just setting there in float maintenance mode but when he switches on lights and fans etc in the RV it jumps up to a few amps and his batteries are already 7 years old n still okay.

We do some extended dry camping in Utah and Colorado which is why I can carry up to 100 gallons of fresh water,,,,,,run 4 Golf Cart Batteries,,,,,,going to install 200 watt solar panel on the roof,,,,,of course an Onan 4KW if needed

My MAIN GOAL is to maximize the life of my golf cart batteries so whatcha think ????????

PS any idea how often I should run the Equalize procedure?? I havent read all the Xantrex instructions yet

John T

This is just confirming anyways what we Sparkies know and some insights for those lay people who are considering batteries and DC loads in general.
If I understand this correctly.You are switching the golf cart to parallel 12V . Then paralleling the golf car to the RV's 12V system.
Certainly using the Xantrex charger on the two combined golfcart and RV battery banks is the right thing to do.
Now if the golf cart and RV systems are connected for an extended period of time while not charging or supplying RV loads. The two battery banks will slow discharge each other.
It takes a bunch of solar panels to provide usable power for housing. As your RV is LP everything except for lights, water pump, stereo, Air conditioning and microwave. Excluding the AC load. The 200W panel isn't enough as it only makes usable power for 6 hours a day. 500W solar would not be too much.
The primary problem with batteries is when Bubba figures he has a DC load that requires 90 amp hour of capacity and purchases an 100 amp hour battery bank. Or poor Bubba purchases an all electric car with 100 miles of range to drive 90 mile trips.
In either case Bubba should have purchased 300amp hours worth of batteries. Or use his 100 mile range electric car for 30 mile trips.

Were it me I would probably remove the old converter, and use the new charger as stated after the word Sooooooooooo. I would use the batteries for some extended non charged operations every month or so such that they get to see some depletion and recharging. but not more than 50% of charge, and not necessarily when I could not expect to charge them soon. If there are 115vac operated components would you not need an inverter. Does the old converter provide that option. Jim

The golf cart is NEVER tied to or has anything to do with my RV (expect for towing it to the tractor shows like Florida Flywheelers twice in the winter). I ONLY meant I'm using deep cycle golf cart "type" of batteries in the RV, four in series paralell for 12 volts and I believe 460 AH at the 20 amp discharge rate.

After thirty years of RV use Im well aware 200 watts of solar isnt enough to run the RV loads constantly butttttttttttttttt during the day we hardly use any 12 volt power while the solar panel supplies at least some energy to my batteries, and then at night we use a small amount of lighting which by the end of the next day the solar has recovered most or all of what we used. Im talkin dry mountain camping at elevations with warm days n cool nights so theres litte electrical energy consumption (stove, water heater etc are LP gas).

Ol John T

While we're on the "battery" subject; is a 12-volt charger in a scooter with gel-cell batteries capable to charge my mower wet-cell battery?

When plugged into shore power theres no need for the Inverter (its only for 120 light duty like cell phone and computer and tv etc when Im dry camping), the shore power has its own AC distribution panel. Ima thinkin Im gonna disconnect the existing cheapie unregulated converter charger and use the golf cart batteris full time on the RV 12 volt loads and let the good quality 3 stage Xantrex keep the batteries wherever they need to be plus power loads when they are in use via the batteries.

John T

i think something has been left out of the equation...without shore power and no inverter...what do you plug the Xantrex into???
better carry plenty of fuel for that Onan.

When I purchased my 02 motorhome the guy said the battery is almost new. Well that wasen't the case. It may be new but I found out when a battery sits something happens inside, and the cells swell up. So I needed a new battery. I decided on two 6 volt golf cart batteries for my 12 V. Now you say you are installing four 6 V. batteries. John, what brand of batteries are you using. Are they all on the same side of the motorhome? I discovered these motorhomes are kind of like a boat. There is always something that needs to be fixed, or purchased. Stan

When dry camping which we do a lot of in Utah or Colorado etc. youre running off the energy stored in the batteries ONLY, theres no shore power in which to plug anything and theres no 120 VAC for the Xantrex battery charger either. However, once I install 200 watt solar panels and since we use very little 12 volts in the daytime and only a few lights at night, maybe charge up the cell phone and run the laptop, were fairly self sufficient a longgggggggggg time especially if I have 100 gallons of fresh water on board.

John T

I will purchase the batteries this week. Sams Club has an equivalent (forget the brand) to the Trojan T 105 and an EG2 I believe which has more capacity, maybe like a Trojan T 125?? Im going with the higher (higher then T 105) capacity unit and will shop and compare next week. I run 4 simply for more energy storage, my buddy has 6 in his RV and we have other friends that use 8 or even 10 woooooooo hooooooooooo

However, with the solar panels and my Onan Genny if needed and 100 gallons of fresh water, the first wife and I can dry camp 7 days fairly easy and by that time we need to find a place to dump the sewage and take on more fresh water, so for those parameters 4 golf cart batteries (around 460 amp hours of storage) is just fine

John T

First - about the AC to DC converter itself. Yeah . . many if not most are loud, buzz and I hate them. I recently yanked out my 30 amp charger/converter and installed an Iota 45 amp unit. It is ABSOLUTELY silent. A huge difference.
The DLS Iota is suited for up to 45 amps - running the DC power in the RV and/or charging the "house" RV batteries. I've got three RVs and all had built-in converters that buzzed something awful. Now I use the Iota. You could stick your ear to it and not hear anything.
There are also smaller and larger Iota models. You should buy the size that matches your battery bank size.

About the deep cycle batteries, life and charging? And automotive alternator cannot charge them properly. But it keeps the up well enough for those times when you are driving. But the peak voltage and charge rate is set wrong in an auto alternator. Whenever parked - you should have a charger hooked to them that is designed to charge them properly. I assume the Trace must be correct for it. A three stage charger is fine except it cannot give an "equalize" mode.

About the "Equalize" mode. Most companies used to it should be done at least once every 6 months. It over-volts the batteries and churns up the electrolyte and suspended minerals so it's more "equally" mixed and thusly enhances battery life. At least in theory. Some battery charger companies now are reluctant to mention it because the pricey AGM (absorbed glass mat) batteries are easily ruined by the "Equalize" process. Trojan now says to measure the electrolyte gravity after the battery is fully charged. If below a certain threshold - the battery must be "equalized." Info at the end of this post.

To equalize, a charger has to be big enough to bring a battery up to 15-16 volts. Not too difficult with one or two batteries - but when you've got 6,8, or 10 of them it takes a huge charger. My Trace charger/inverter can charge at 120 amps.

Equalizing (flooded/wet batteries ONLY) - this info from the Trojan battery company.

Equalizing is an overcharge performed on flooded/wet batteries after they have
been fully charged. Trojan recommends equalizing only when batteries have low
specific gravity, below 1.250 or wide ranging specific gravity, 0.030, after fully
charging a battery. Gel or AGM batteries should never be equalized.
• Confirm that the batteries are flooded/wet
• Check electrolyte level to make sure plates are covered with water before
charging
• Check that all vent caps are secured properly on the battery before charging
• Set charger to equalizing mode
• The batteries will gas (bubble) during the equalization process
• Measure the specific gravity every hour. Discontinue the equalization charge
when the gravity no longer rises
WARNING: Do not equalize gel or AGM batteries.

This info about automotive voltage regulators and why they cannot charge deep cycle batteries properly.

Car voltage regulators will not work well in deep cycle
applications. The regulator makes its decisions based
only on the system’s voltage. This is fine with the
average car battery which is cycled to less than 1% of
its capacity before being refilled. However, the deep
cycle battery is almost empty when it is recharged. The
car voltage regulator attempts to instantly bring the
system’s voltage to 14–15 Volts. A 12 Volt deep cycle
lead-acid battery will not reach a voltage of 14 Volts
until it is almost filled. The net result is that the car
regulator dumps the entire output of the alternator into
the batteries until they are full. This is almost always
too much energy too fast for a fully discharged battery.
To compound the problem, the car regulator’s voltage
limit is set too low for deep cycle service. This low
voltage limit means that the batteries are charged too
slowly when they are almost full, resulting in many
extra hours of generator operation to totally fill the
battery pack. Since the car regulator is set at about 14
Volts, we are unable to raise the system voltage up to
over 16 Volts for the essential equalizing charges.

Go here to read about the Iota DLS power-supply/battery chargers. Available in 15, 30, 45, 55, 75 and 90 amp.

I've got the DLS 45 and love it. It runs house DC power, gives three-stage normal charging and and "equalize-over-ride" mode.

http://www.iotaengineering.com/12vdc.htm

Thanks my Sparky friend, I'll go take a look see. My Xantrex Truecharge 2 has the Equalize feature so after six months or so I may give it a whirl. It also has the automatic 3 stage Bulk/Absorption/Float and is capable of charging deep cycle golf cart batteries.

Ive decided to disconnect the old existing cheapie noisy buzz box converter and have my RV ALWAYS fed from my 4 golf cart batteries and anytime Im plugged to shore power I will let the Xantrex keep the batteries charged and supply my modest (lights and a vent fan) 12 volt house loads. I can have the chevy alternator connected to the house batteries while driving but realize as you posted thats NOT the right way to charge my deep cycles.....

John T

When it comes to charging deep cycle batteries from an automotive alternator - there IS no cheap way to do it correctly - that I know of.

There are "battery to battery" chargers made for that specific purpose but they are very pricey. Used mostly for marine use. The charger hooks to the starting battery - and converts that into a voltage and charge sequence that goes to the RV battery (or battery bank). Basically - it's just a 12 volt deep-cycle battery charger with a 12 VDC input instead of 120 VAC. Last one I looked at was over $400 and not worth it for an RV with a few deep cycle batteries.