Deep Cycle batteries

[49erRam3500]

Bought a Wildcat 28RK in Feb 2009, retired and hit the road. Recently, I lost battery strength and then complete power in about 1 1/2 days of dry camping. When I got home, I took the batteries(Interstate) to Batteries Plus and had them tested (recharged while driving). They tested perfect for voltage and AMPS and had not lost any fluid. Do deep cycles lose their durability after 1 1/2 years? I used to be able to go 4 days before the battery status would begin to diminish.

Is it possible that there is another drain on the batteries? I only use the fridge, pump, and H20 heater with minmial lighting at night.

Any ideas?

49er RAM

[windrider]

Are you sure nothing else was on, like a light in a storage compartment? Maybe the radio left on. All batteries age and loose ability to maintain a charge, and supply current over time. When is the last time you dry camped for 4 days with them? Did you use about the same amount of water this time as last time? Of the things you mentioned, the pump is the big draw. Lot of questions still to answer. Also do you have 2 12 volt, or a pair of 6 volt, what is your configuration? And when do you plan on camping next? Hope you have a voltmeter and know how to read it, and I can offer you a few things to check.

[milzat]

A constant draw on the battery is the Propane Leak Detector.

You may want to think of addid a 2nd 12 volt battery in Parallel, or installing two quality 6 volt deep cycle batteries in Series.

Below is a link and video that may help.

DEEP CYCLE BATTERY FREQUENTLY ASKED QUESTIONS

YouTube - Deep Cycle Battery Tips

[49erRam3500]

Originally Posted by windrider

Are you sure nothing else was on, like a light in a storage compartment? Maybe the radio left on. All batteries age and loose ability to maintain a charge, and supply current over time. When is the last time you dry camped for 4 days with them? Did you use about the same amount of water this time as last time? Of the things you mentioned, the pump is the big draw. Lot of questions still to answer. Also do you have 2 12 volt, or a pair of 6 volt, what is your configuration? And when do you plan on camping next? Hope you have a voltmeter and know how to read it, and I can offer you a few things to check.

More details- My rig has 2 12V Interstate batteries. The propane detector is what alerted me to the battery failure. While the pump is the main draw, it is operating normally and we are frugal with the useage. The H20 pump is OFF at night as is the H2O heater. I checked for lights on in the cargo bay and security lights. All off. This problem first occurred after a four month storage period and repeated on another trip four weeks later.

I do have a multimeter. Is there a way to test for a draw on the system?

[milzat]

Originally Posted by 49erRam3500

I do have a multimeter. Is there a way to test for a draw on the system?

Battery Drain Parasitic Draw Testing

Check for battery drain video.

[windrider]

If the problem started after a 4 month storage, and the batteries had not been disconnected, then parasitic draw killed them, probably. They may have been discharged too far to recover. Were they charged by plugging the unit for at least 3 days before your trip? They would need a good, slow, 3 stage charge to recover, if they ever will. I don't know if your camper has a 3 stage charger or not. I'm going to assume the post above help, but if not, let us know, and we'll walk you through some checks with the meter.

[NWJeeper]

Originally Posted by 49erRam3500

More details- My rig has 2 12V Interstate batteries. The propane detector is what alerted me to the battery failure. While the pump is the main draw, it is operating normally and we are frugal with the usage. The H20 pump is OFF at night as is the H2O heater. I checked for lights on in the cargo bay and security lights. All off. This problem first occurred after a four month storage period and repeated on another trip four weeks later.

I do have a multimeter. Is there a way to test for a draw on the system?

First of all, your 12 volt batteries are not true deep cycle batteries, I don't know of any 12volt batteries that are. It has to do with their construction. You need a real good idea of what the amp hour rating of the batteries are. Most group 24 or 27 batteries run somewhere between 70 and 105 amp hours. Double the rating since you have two. This isn't very much.

To be able to see the draw on your system you really need a shunt which goes in line with the ground cable on your batteries and the frame of the RV. You can then use a amp meter to see exactly what is being used. I highly recommend that anyone who dry camps should get set up with a Trimetric 2025 battery monitor or other such system to keep close tabs on what is going on. It is a real eye opener as to how they are charging and discharging.

[camprat]

I have 4-6volt batteries & 110 watt solar panel setup for charging for the day time hour to cut back on generator time. We dry camp a lot at the lake, run fan all night. You may what to check on adding batteries. There are A lot more parasitic draw now with RV. When we got our Wildcat it to came with a little Interstate. WE just made it through the night running the furnace. The next day it was gone & the 6 volt were in place. the down side to 6 volts is finding room on TT to put them, for those with TT ,You may want to think about high capacity d/c 12volt. If you don't have a battery disconnect switch, take the cable off battery one will due, when in storage.

[windrider]

All this is good advice, and may be needed, but I think you are getting the cart before the horse. First of all, the problem has not been clearly defined, at least not that I can tell. Second, you can spend money, add batteries, solar panels, and other stuff, and go way over what the original poster my need or require. Last picky item, a shunt is usually a one ohm, 50 watt, resistor placed in line with the batteries in which you use a VOLTMETER to read the voltage across the shunt. Ohm's law will make the voltage reading equal to the amperage draw by using a 1 ohm resistor. ( 1 amp times 1 ohm equal 1 volt). Give the guy a chance to answer the questions in post number 3, then see if the problem can be determined. (90% of problem is in identifying the problem.)

[kbrown1075]

While we are on batteries, please note this from Wikipedia about Pulse Charging:
Pulse
Some chargers use pulse technology in which a pulse is fed to the battery. This DC pulse has a strictly controlled rise time, pulse width, pulse repetition rate (frequency) and amplitude. This technology is said to work with any size, voltage, capacity or chemistry of batteries, including automotive and valve-regulated batteries.[2] With pulse charging, high instantaneous voltages can be applied without overheating the battery. In a Lead-acid battery, this breaks down lead-sulfate crystals, thus greatly extending the battery service life.[3]
Several kinds of pulse charging are patented.[4][5][6] Others are open source hardware.[7]
Some chargers use pulses to check the current battery state when the charger is first connected, then use constant current charging during fast charging, then use pulse charging as a kind of trickle charging to maintain the charge.[8]
Some chargers use "negative pulse charging", also called "reflex charging" or "burp charging".[9] Such chargers use both positive and brief negative current pulses. Such chargers don't work any better than pulse chargers that only use positive pulses.[10][11

I hi lighted an area that talks about lead acid batteries. The pulse charge method can also bring back what is thought to be a "no good" battery. You can use the a small pulse charger with a regular trickle charger to help maintain clean plates in your battery.