2 chargers connected to one battery bank?

You can connect similar chargers in paralell but it sounds like the new charge is more advanced so it's probibly not a good idea. Your batterys might be in series-paralell , in which case you can charge each pair with each charger. The problem with that is that banks will not reach full charge at same time which is ok if you wait until both pair are at full charge. Otherwise the lesser charged pair will be unduely stressed under load. You should read for yourself what battery and charger manufactures say about quick charging depleted batteries. Throughing a 100 amp charge on a battery for secounds to replinish the power consumed by say starting an engine has a far different effect than throwing 100amps on a heavyly discharged battery. Esp repeatedly doing it.

Unless the charger is rated at a lower current output than the battery back requires, the battery state of charge (SOC) will determine the current it will accept. So adding chargers will only consume unnecessary energy and add complications.

Use your best charger as the default and reserve the other for a backup. Exercise the backup occasionally. That would be how I would do it.

I upgraded my real old single mode converter/charger to a WFCO 45AMP smart mode converter/charger only to find out I could never get my WFCO unit to go into smart mode charging.

Then I purchased a PD9260C 60AMP smart mode converter/charger but I mounted it stand alone closer to the battery bank. I decided to leave the WF8945 unit in its location in the bottom compartment of the WF series Power Distribution Panel.

I ran a 120VAC connection to the PD9260C from another circuit breaker in my panel.

I most of the time use the PD9260C by just flipping the circuit breaker for this unit and have the WF8945 converter turned off by flipping its circuit breaker.

I only have the brand new WF8945 converter around for back-up purpose. I only have one converter turned ON at a time however I don't think it would harm anything having both of them on. It just didn't seem like having two converter units ON at the same would be a good idea.

You can see where my two converters are installed in this floor plan drawing of my trailer...


This is a schematic diagram of my how my two converters are wired in my setup...


There is some posts on here where a B&D VEC1093DBD smart mode portable battery charger was being used along with the on-board trailer converter/charger to get to full 100% charge state on the batteries quicker.

Roy Ken

Given that smart chargers vary the voltage throughout the process, and that dumb ones do not, this suggests to me that having both a dumb and a smart charger on the job at the same time would be a bad idea. I can see the smart one throwing 13 volts at the other one that is putting out 12 volts, thus having the lower voltage unit force fed current backwards. Charging a battery charger is not what they were designed to do. I'd anticipate possible overheating and circuit damage.

So I'd say one or the other, mate, but never both.

You can have multiple chargers connected. No damage will occur at all. I've done this myself a number of times. Hopefully the charging king, BFL13, will chime in. You won't gain much by having the dumb charger connected though. They typically have very low charge rates anyways. Just use the Powermax.

Hi,

You can use both at once. You may have to experiment with the order--i.e. put on the smart charger first, and then add the dumb one or visa versa.

I've always thought that connecting two chargers would not work because:
One charger would see the higher voltage of the other and think the battery is already charged.

Hi hershey,

Never the less, it does work to have two chargers going at once. The charger with the lower voltage will "drop out" once the battery voltage rises to that set point.

hershey wrote:
I've always thought that connecting two chargers would not work because:
One charger would see the higher voltage of the other and think the battery is already charged.

It's going to depend on the chargers you use, whether or not they will work together. I"ve tried it with my smart charger and found that it uses the batteries voltage to determine the rate of charge so when I hook up another charger it reads the battery as being fully charged and just shuts down.

only problem I see with running two chargers is they may drop out of "boost" mode earlier thinking the batteries are near full, as it takes less amps to maintain a set voltage. Once the actual battery voltage climbs high enough, they will taper amperage to maintain it, then shift to float voltage. With the batteries say 80% charged you don't want the charger dropping to float mode because the amps going out of the charger got to low.