Recommendations for Converter/Battery Charger?

E350 · 06-08-2013, 11:56 PM

I am using a BatteryMinder 12248 for "trickle" charging (it only goes up to 8 amps) my 250Ah UPG house battery.

But I also need a converter charger to bring my house battery back to full charge after a significant discharge.

My $2500 2500W Xantrex Prosine Inverter/Charger bit the dust, so I am looking for a good converter/battery charger only. (I never want to have an inverter/charger again. I want each to be separate so that they can be replaced separately when one or the other eventually dies.)

BroncoHauler's thread (thank you!) "Battery Charger 101" links to a tech thread which contains the following battery to charger size formula:

"How large of a charger should I have?

... So, what’s the optimum charger? The general rule of thumb is C/5, or
Capacity (in amp-hours) divided by 5. So an 80-amp charger is the
right size for a 400Ah battery bank (400/5=80)."

Applying that rule of thumb to my 250Ah house battery (250/5=50), it seems that my converter/charger should be at least 50 amps. But I wouldn't mind going up to 60 or even 75 amps (would I run the risk of frying my battery with an 80 amp charger?) so that I would have some extra charging capacity if I replace the current battery with a larger battery or multiple battery bank.

So any recommendations for a reliable, long lived converter/battery charger would be greatly appreciated.

E350 · 06-09-2013, 12:07 PM

Boy, nothing like throwing a thread party and having nobody attend...

So, after more reading it seems that a three phase charger is better than a converter/charger?
Apparently, the primary focus of converter/chargers is to convert AC to DC to run your appliances while on shore power and only secondarily do they charge your battery and not very well at that.

So, anybody have any experience with:

Samlex SEC-1250UL

or

Samlex SEC-1260A.

Interesting statement on the former:

"IF YOU ARE GOING TO DRIVE THIS CHARGER WITH A GENERATOR, YOU NEED 3 TIMES THE MAX AC DRAW LISTED FOR THE CHARGER AVAILABLE FROM THE GENERATOR. THIS HAS TO DO WITH THE SWITCHMODE NATURE OF THESE CHARGERS. CALL IF YOU NEED MORE INFO."

http://www.chargingchargers.com/charger ... 250UL.html

I had to pay $500 to redo the computer on my Auragen 5Kw genset because it was pulled over limit by my power hungry Prosine 2500 so I am concerned about the "switchmode" deal on the Samlex SEC-1250UL.

I will call these ChargingCharger.com guys and report back.

KTMRIDER · 06-09-2013, 05:31 PM

I am running a Xantrex TrueCharge charger. Allows me to charge both the house and van batteries as separate banks. It also self adjusts when using a generator and will flash the low/no AC fault if AC power isn't enough to charge.

Example is this weekend in Mammoth boondoking I had the Honda 2000 running and charging the batteries. When I turned on the microwave there wasn't enough juice to run the micro and charger so the red light came on and the the charger stopped charging automatically. I had the option of manually turning off the charger with the remote panel or reducing the charge %. Once I adjusted the charge % Down to 20% the generator could run the micro and charge.

When at home I have it hooked up on the Xantrex and on the road I use the Narional Luna dual charging system. I had to obviously wire it creatively with a marine switch. I also have a separate inverter for when I just want 110 but not use the generator. I can even run my house AC for short periods on just the inverter if needed. I also added an Automatic Tranfer Swtich for safety so nobody steps on each other.
Eric

E350 · 06-09-2013, 05:34 PM

Thank you very much for the reply. We skied Mammoth just last month, early May.

I looked at the TrueCharge2. But I am gun shy of Xantrex. How long have you had yours and what model? Finally what is National Luna Dual?

KTMRIDER · 06-09-2013, 06:21 PM

Quote:

Originally Posted by E350

Thank you very much for the reply. We skied Mammoth just last month, early May.

I looked at the TrueCharge2. But I am gun shy of Xantrex. How long have you had yours and what model? Finally what is National Luna Dual?

I had also heard poor things about certain previous Xantrex chargers when doing research. This one my original interior builder Derek from Colorado Camper Van had found and when I checked had decent reviews. I liked how it would charge the banks separately so I agreed and went for it. I have had it for several years and it has been very reliable. My inverter is also a rebaged Xantrex and has been reliable so far.

The National Luna kit (http://www.equipt1.com/companies/Bat...attery-systems) is just one of many dual charging systems designed to keep both the van and house batteries charged. This kit will monitor your van batteries after 5 minutes and decide if the van batteries are charged enough to allow it to connect and charge your house batteries as well. I like the monitor it provides so you can always keep an eye on both banks.

This is a great system if you actually read instructions and install it properly. CCV didn't bother with instructions and wired it his own way frying the boards in this system within 2 hours on my drive home from CO to CA. I point this out because there are other systems that have less electronics and are not as critical on the setup. Once I replaced the boards and rewired the system as per the instructions all has been well for several years.

I would also read up on Expedition Portal under the 12v Power Systems section on the different options. You can get a broader view of people using these types of systems in different configurations. I rewired my whole van last year myself as I was displeased and scared of the original builders so called wiring job, including the nice orange extension cord that was hacked and used for my power cord....

Eric

McZippie · 06-11-2013, 12:05 AM

I have a 40 amp samlex charger in our rig. Can't remember the model number but it's the older blue one. Had for 3 years now with no problems.

The spec on yellow model lists that it also has settings to work as a DC power supply.
That's an important feature so batteries don't over charge while under load.

I keep the settings on UPS/DC power supply all the time, and while at home charge the batteries with 3 stage battery maintainer/charger.

PearGrove · 05-18-2014, 10:57 PM

Ktmrider, did you find a good location to install National Luna's isolator-solenoid? I installed that system two years ago on my rig (2003 E350 V-10), and am unsatisfied with the location I chose: underneath the starter battery tray, inches away from the radiator. It was very difficult to access in that spot, so I wound up using only two of the four mounting screws. The system worked great for two years, but the screws eventually loosened, and then the isolator rattled for a month before I figured out what was rattling, and now it's not working. I'm planning on replacing the isolator with an identical part, because the National Luna system worked great for me until now, but I'm wondering if there's a better spot to install the isolator this time around.