Hello All,I just upgraded the single 12 volt battery on my hybrid travel trailer to dual US Battery 6 volts. I purchased a Boondocker "smart" converter/charger to install into the original Elixir 45 amp panel that is in the trailer. So I believe I have handled the "smart" charging needs of the new batteries, when they are installed on the trailer, and when plugged into shore power or when using my generator.My trailer is not stored in a location where I am comfortable leaving the batteries on the tongue. In the future, I will design, and build a locking system. But for now, I am removing them when I am not using the trailer, and storing them in my garage. So here is my question.....I am in need of a reasonably priced charger that will both charge, and maintain the 6 volt batteries while they are in storage. I would like to find something that kind of does its own thing, and doesn't require constant monitoring. It would also be nice if I could use the charger for my other vehicle batteries. So what would you guys recommend?I have looked at the NOCO genius G3500, the Deltran Battery Tender Plus, and the Schumacher Speed Charge.Any reviews of the aforementioned chargers or suggestions on something else would be great.Thanks,Jeff

2, 3 or 4 x http://www.homedepot.com/p/Grape-Solar-100-Watt-Polycrystalline-Solar-Panel-for-RV-s-Boats-and-12-Volt-Systems-GS-Star-100W/2042113651 x http://www.homedepot.com/p/Grape-Solar-40-Amp-PWM-Solar-Charge-Controller-with-Bluetooth-GS-PWM-40BT/2071008561 x http://www.homedepot.com/p/Southwire-50-ft-12-2-Stranded-Low-Voltage-Landscape-Lighting-Cord-55213442/301982435

I'm still using my VEC1093DBD Portable Black & Decker 40AMP Smart mode charger...I also have a smaller 10A smart mode charger I picked up from WALMART...Seems like they are wanting us to use the 14.8VDC model smart mode chargers now for the two 6V GC2 batteries in series... My on-board converter/charger is a PD9260C and it only puts out 14.4VDC in BOOST charging mode. I am also just now going to a 6V GC2 battery bank so may have to deal with some changes here myself later on...I have been running multiple 12V 85AH batteries in parallel since I purchased my OFF-ROAD trailer in 2008. Just last season the Interstate batteries started to fall off on performance and gave up the ghost... Not bad I reckon for many 50% to 90% charge cycles over the years... Just now building up a new battery bank and going to use two groups of two each 6V GC2 batteries in series to give e around a 440AH capacity battery bank. Most of my camping is OFF-ROAD back on a creekside spot somewhere or up on a close by MTN Ridge...I don't know if we can get away with using the 14.4VDC charger modes and just count on charging longer or not when charging the 6V GC2 batteries...Roy Ken

I recommend the 8 amp Battery Minder brand. The rest are good also but get 5 amps minimum.JMHO

jwstrout wrote:I have looked at the NOCO genius G3500, the Deltran Battery Tender Plus, and the Schumacher Speed Charge.If you're considering NOCO you should also take a look at CTEK Chargers. Since my built in WFCO 8955 converter never bulk charges at 14.4 volts (as it's supposed to do) I turned it off and instead use a CTEK Mulit US 7002 which does achieve a proper 14.4 volt bulk charge. During the winter I use it in my workshop to maintain the trailer battery ... not inexpensive, but works great. :B

I bought a NOCO 3 years ago - but it was worthless as a deep-cycle charger. It would not hold an absorb charge but instead immediately drop to float voltage once it reached 14.4V. My current autocraft gold "smart charger" does the same. For keeping a battery charged (maintenance) over time in your garage, most chargers will work fine but if you need to actually recharge the battery, getting one that actually holds a charge voltage is valuable.

Best Stand Alone Charger? | Good Sam Community

jwstrout
Explorer
Jun 20, 2017
After being disconnected for about 8 hours, readings at the battery terminals was 12.82. So it appears that the BT did its thing. When I checked electrolytes, all cells looked good. When I reconnected for float/maintenance, the red light on the BT came on again, indicating that it is charging. That has been the case for about 4 hours. So we will see how long it takes to go into float mode again.

I did get the Boondocker installed today, and made sure at least the converter portion was working. Seems good to go, but I won't get a chance to actually test it in the real world until the July 7th weekend, when my honey, and I take the trailer out again.

Thanks to all that helped, and I will let you guys know when the solar bug hits me.

Jeff
jwstrout
Explorer
Jun 18, 2017
Thanks for the information on static voltage. I will post results when I get a reading.

Jeff
MEXICOWANDERER
Explorer
Jun 18, 2017
Takes forever and three 29ths of February to charge a battery is a TRICKLE charger.

And yes, a disconnection after charging and waiting six hours is enough time to take a voltage reading. With today's 1.285 specific gravity batteries, I would believe the minimum static voltage would have to be 12.78 volts at 25c or the battery is not fully charged.
jwstrout
Explorer
Jun 18, 2017
The green light started flashing about 2 hours ago, indicating that the batteries are at 80% or better. I just pulled a reading of 14.5 volts at the BT terminal connectors. So it appears to be working. Once it goes into float mode, I will disconnect, let them sit, and test again. I figure I'll check electrolyte levels, then put the TB back on for float, and battery maintenance, until the next trip.

I also figured I'd check electrolyte levels once a week, when I drag the lawn mower out.

I haven't gotten to the Boondocker install yet. However, I am off tomorrow, and will get that done as well.

Just so you don't think I was ignoring what I am sure was sound, and knowledgeable advice, I somehow missed the 5 amp minimum suggestion until after I had already purchased, unpacked, and began using the BT.

Thanks again,

Jeff
time2roll
Nomad
Jun 18, 2017
jwstrout wrote:
Thanks for the information.......I am assuming these comments mean I should use my nifty new multi-meter to test the voltage,(after disconnecting, and letting the batteries sit for a couple of hours of course) and make sure that they are actually fully charged? As of right now, they have been on the BT for a little over 30 hours, and it still shows a red light, indicating that they are charging. Oh, and what does IIRC mean?

Go ahead and use the voltmeter while charging to see that you get 14.4+ before BT says full charge and drops to float. Trouble is a fully charged 200 amp/hour battery can burn off 1 amp to electrolysis as it reaches full charge. So the BT+ at 1.25 amps is going to be real slow at the end. This is why I recommended 5 amps minimum up above.

IIRC - If I Recall Correctly
jwstrout
Explorer
Jun 18, 2017
Thanks..........they are currently connected together, and being charged as if they are a 12 volt.

Jeff
wa8yxm
Explorer III
Jun 18, 2017
My advice is do not charge the six volt batteries. Charge the 12 volt batteries, same as you do when they are in the RV..

SAY WHAT

Hook them up on the bench exactly as they are in the RV, two 6v in series, making one 12v.. Then you can use a standard 12 volt battery maintainer on them Just as you would a 12 volt 4D battery.

Or you can use a Progressive Dynamics 9200 for storage the SMALLEST one will do, that's the best.
jwstrout
Explorer
Jun 18, 2017
"Keep an eye on the BT if the battery is low. IIRC if BT cannot hit 14.6 in ~72 hours it still drops to float. Near full charge should not be an issue."

"Boondocker tends to drop to normal mode (13.6) at 70 to 80 percent charged as it only holds boost voltage for 15 minutes after hitting the target. That is converter voltage not the battery."

Thanks for the information.......I am assuming these comments mean I should use my nifty new multi-meter to test the voltage,(after disconnecting, and letting the batteries sit for a couple of hours of course) and make sure that they are actually fully charged? As of right now, they have been on the BT for a little over 30 hours, and it still shows a red light, indicating that they are charging. Oh, and what does IIRC mean?

"Both of the chargers you are buying will not harm your batteries. Floating them at a constant lower voltage is the best care you can give them."

Thanks........that's what I really wanted to hear. I will also look into a solar system in the near future. But for now, I need to figure everything out what I have already purchased.

Jeff
westend
Explorer
Jun 18, 2017
Hopefully both of these devices will work. My life was a lot easier before I started hanging out on these forums, and trying to learn. Don't get me wrong, you guys are great, but sometimes ignorance is bliss....
No, it isn't, unless you consider "bliss" as having to replace batteries sooner than optimal. ;)

You may wish to consider adding a solar panel and charge controller or buying a power supply since there are reasons to get charging voltage to around 15 V, at times. That is considered an "equalization" procedure and, as batteries age, it will extend the capacity of your batteries. I don't know what US battery specifies as a routine charge voltage but the 6V batteries I've dealt with all liked a diet of 14.8 V or higher.

Both of the chargers you are buying will not harm your batteries. Floating them at a constant lower voltage is the best care you can give them.
time2roll
Nomad
Jun 18, 2017
Keep an eye on the BT if the battery is low. IIRC if BT cannot hit 14.6 in ~72 hours it still drops to float. Near full charge should not be an issue.

Boondocker tends to drop to normal mode (13.6) at 70 to 80 percent charged as it only holds boost voltage for 15 minutes after hitting the target. That is converter voltage not the battery.

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