Best Stand Alone Charger?

[jwstrout]

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

[jwstrout]

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]

Thanks for the information on static voltage. I will post results when I get a reading.

Jeff

[MEXICOWANDERER]

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]

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]

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]

Thanks..........they are currently connected together, and being charged as if they are a 12 volt.

Jeff

[wa8yxm]

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]

"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]

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]

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.

[jwstrout]

According to specs, the Battery Tender Plus runs 14.6 for "absorption", and 13.3 for "float". The Boondocker runs 14.6 for "boost", 13.6 for normal, and 13.2 for "float".

I am not worried about speed on the Battery Tender Plus. When the batteries aren't on the trailer, and it is hooked up in the garage, it will have days to do its thing. I am more worried that it is capable of fully charging, then maintaining, and not causing damage.

The Boondocker needs to be as quick as possible, since it will be powered by my generator while camping. But besides a little speed, the requirements are pretty much the same. Capable of fully charging, then maintaining, and not causing any damage.

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....

Jeff

[westend]

The Battery Tender Plus will be great for maintaining your batteries. If that Boondocker gets up to 14.8 V, it will be a winner, too.

FWIW, I've recently started using a low amperage 12 V power supply I had laying around to maintain my loose batteries. My loose batteries are auto style but the power supply would do a good job charging deep cycle batteries. The OC Voltage is around 15V. Depending on SOC of the batteries, it takes a couple of days to put a full charge into them and operation is completely manual. Previously, I had used a 12V wall transformer. That works, also, but has a lower OC voltage and doesn't push as many amps.

[RJsfishin]

The battery Tender plus is one of the best choices you could have made. Mine is as old as dirt, and still never misses a lick. And it is the only charger out of 3 different brands that has not failed.
Over a 10 yr period, I have had 4 Schumacher chargers, fail in hot weather.

[MEXICOWANDERER]

OXYMORON OF THE YEAR perhaps of the century

Portable Fast Battery Charger.

Love it. A battery charger that takes 14 hours to bring a battery to 75% state of charge. California approved.