Battery use

[savery]

My new battery never seems to have enough power to move the hitch or slides. I replaced the new units OEM as it had no power even after trickle charged for several hours. I replaced it with the same battery as the unit came with. Should the battery switch be left on when plugged into electric or off. Shouldn't the electric (or the vehicle when trailering) be charging the battery? Any way to check to see if a charge is going to the battery?

[Leisure Time Larry]

You need to check your RV battery with a voltmeter/multi-meter. What is the voltage of the battery in DC? It should be 12.0 volts or higher. Plug into electric power. Re-check the battery voltage while plugged in. What is it? It should be 13 volts or higher. If so, your battery is being charged when plugged in.

Typically, the battery switch needs to be on to charge the battery, but it just depends on how your RV is wired. Again, you need to experiment with testing voltage.

Does your tow vehicle charge your battery? Again, it depends on how your RV is wired. Test the voltage of the RV battery. Hook up your tow vehicle and trailer and start the tow vehicle. Check the voltage on the RV battery again. Did it go up? If so, yes it's charging.

Watch some YouTube. Get a meter. Do some testing. Good luck.

[Chuck v]

Check for clean connections and cables in good condition. Since the old and replacement batteries behaved in a similar manner, it may not be a voltge issue but a current carrying related issue. Lead Oxide is a clear oxidation often forming on battery terminals and clamps, and it is an insulator. Just brushing does not cut it -- literally! Use a knife or scraper to get down to a shiny surface when connecting. Inspect the cables themselves for any sign of overheating, such as stiffness near the terminal or discoloration...replace as needed.


Chuck

[THenne1713]

battery switch ON, and ONLY OFF FOR STORAGE WHEN NOT PLUGGED IN. TRICKLE charger MIGHT take 24+hours to charge, if battery was low enough. YES, should charge from TOW vehicle if wire thru (properly wired/ properly working) 6-pin or 7-pin harness. TESTING: AFTER CHARGING, DISCONNECTED, WAIT 30-MINUTES FOR FALSE HIGH SURFACE VOLTAGE TO DISSIPATE, charged Battery 100%= 12.6-12.7vdc, 50%+=12.0.-12.1vdc VERIFY CHARGING if voltage during charge is greater than 13.0 volts

[THenne1713]

Rereading/ Thinking further, I agree w/ Chuck v, BUT... issue may well also be at GROUND CONNECTIONS AT THE FRAME. 1) Follow/ remove, clean, reinstall NEG battery cable from battery, and 2) Ground cable at EACH device (Hitch jack, slide motors) and 3) Make sure WHITE WIRE CONNECTED/ CLEAN/SHINY at Hitch harness wiring, FOR PROPER OPERATION AND PROPER BATTERY CHARGING. Good Luck

[Chuck v]

Henry111,


Did you change the converter/charger to accommodate the AGM chemistry of the VMaxTanks? Most recommendations admonish against using flooded cell charging profiles (conventional lead acid 'wet' batteries) for either AGM or gel-cel batteries. Advanced float chargers, like those built into the Inverter controllers built by Magnum and others have program settings for this specific type of battery -- but the house battery charger built into the 12 volt converter typically won't have this feature. Your travel trailer most likely does not have a setting for AGM maintenance on its charger.


You typically find statements like the following:
Both AGM and gel batteries are naturally more stable and have much lower discharge rate than flooded cell batteries. They also have different needs from flooded cell batteries, and a charger configured for flooded cell batteries may burn out VRLA batteries, and cause them to die.


Basically, you can charge the batteries with the built-in converter, but be cautious about keeping them on trickle or float charge for a long duration as that is the condition that is at most risk.


Chuck