Redundant Battery Charger Configuration

[BorisM]

Originally Posted by Bmatlock00

Install a led volt meter and if she sees the voltage slowly start to rise after plugging in the charger then the charger is working. If you're really that worried about the charger failing, then buy a second charger, if the first charger fails then plug the back up charger in.

There got to be a sophisticated way of doing it. It is hard to imagine I am the only one with this crazy idea.

[BorisM]

So, this is what I found so far.



One of my chargers is 10A the other one is 15A, so if I connect both of the them I get 25A 48V output. Am I correctly reading it? My charger amperage is not the same? Do i get 30A or 20A?

[cgtech]

The pic looks correct for your needs. From what you have described, you would have a max of 25a charge current. Have you taken into consideration that your redundant system may actually cause the problem you are trying to avoid? If both chargers are plugged into outlets serviced by the same circuit breaker in your electrical panel, and the load of 2 chargers trips the breaker during the night, your "fix" has become the "problem". Not trying to be rude, but if your wife is gonna rely on a golf cart for everyday transportation, she should be knowledgeable in the operation of the charging & use, to a degree that she could tell if something is amiss.

[BorisM]

Originally Posted by cgtech

The pic looks correct for your needs. From what you have described, you would have a max of 25a charge current. Have you taken into consideration that your redundant system may actually cause the problem you are trying to avoid? If both chargers are plugged into outlets serviced by the same circuit breaker in your electrical panel, and the load of 2 chargers trips the breaker during the night, your "fix" has become the "problem".

That did cross my mind, and I haven't figured out a solution yet.

[Sergio]

Don't try it as it is not going to work with your chargers...

Those IOTA chargers are specialized chargers designed to work as a "network" and use a single controller.

If you read further on the same place you got that picture from, You will see the following:

While smart chargers deliver clear charging benefits, multi-charger applications
can present challenges to chargers with built-in smart charge control technology.
In this case, the charge controller manages the individual charger when the purpose
of the series or parallel configuration is for the chargers to work together
for total increased output voltage or increased amps. Chargers with built-in controllers
can interfere with each other in their various charge stages of bulk, absorption,
float, and equalization and the batteries may not reach full charge. In
operations where auxiliary battery power is mission critical, chargers with built-in
controllers can contribute to decreased battery performance and battery life.

The only solution for your redundancy would be to invest in 2 IOTA chargers and an External Smart Charge Controller.

[Sergio]

I hate to leave this thread on a negative note, so here is one idea:

Instead of trying to use 2 chargers in parallel for redundancy, what about using them sequentially?

The second charger should be the one with a "float" mode, or it can just be a "float" charger.

You will need:

a) A smart power strip with a Master, a controlled and a always ON outlet. This is just one example:

Amazon.com: Monster Power Digital PowerCenter MDP 500 - 6 outlets, 1080 joule rating

Amazon.com: Monster Power Digital PowerCenter MDP 500 - 6 outlets, 1080 joule rating

b) A SPDT 120v relay like this one:

Supco 90382 General Purpose Fan Relay, 18 A Load Current, 120 V Coil Voltage, Normally Open and Normally Closed Contacts

Supco 90382 General Purpose Fan Relay, 18 A Load Current, 120 V Coil Voltage, Normally Open and Normally Closed Contacts

c) 2-short power extension cords of different colors that will be cut and spliced.


The idea would be to plug the "primary" charger to the master outlet of the power strip.


Run the "hot" wire of one of the power cords through the N/C contacts of the relay.

Cut the other power cord and run the end with the plug to the relay coil terminals.

Plug the "second" charger to the female end of the power cord that runs through the relay N/C contacts.

Plug the power cord that runs through the N/C contacts to the always ON outlet of the power strip.

Plug the cut power cord that runs to the relay coil to the "controlled" outlet of the power strip.

So now when You plug the power strip in:

The "primary" charger will turn ON.
The "controlled" outlet will power ON due to the current use of the Master.
The relay will turn ON and disconnect the "second" charger (N/C contacts open).

Once the Primary charger is done charging:

After a small delay The "controlled" outlet will power OFF since there is no current on the Master outlet.
The relay will power OFF and the N/C contacts will close again.
The second charger will come ON.

If the primary charger worked, the second charger will go into float mode since the pack voltage will still be pretty high.

If the primary charger has failed (or was not plugged in) , the second charger will do a regular charge.

You can even plug a small night light to one of the other power outlets so you know the whole thing is working from a distance.

The whole thing should cost less than $40.

[jjance]

If she can't remember to connect one charger up. How can you expect her to connect two up? Its like my wife, she would rather run out of gas than stop at a gas station.

[Sergio]

That was the design goal, both the OnBoard charger and the float charger will be On Board and plugged to the AC outlets of the On Board mounted smart power strip.

The only plug that needs to be connected is the AC plug from the On Board smart power strip.

If You also plug a night light to one of the other "controlled" outlets, You get an AC powered indication while the main charger is running.

I actually was planning to built one for me if I ever need to add a float charger since I have all the parts.

The smart power strip I have is no longer on Amazon, but if You get one with more than one "Always On" outlet, You can add another night light of different color to a "Always On" outlet to have an AC powered indication that the smart power strip has power.

http://www.amazon.com/TRIPP-AV86G-Outlet-6-Feet-Protector

http://www.amazon.com/TRIPP-AV86G-Outlet-6-Feet-Protector

That should eliminate the vast majority of preventable issues.

[BorisM]

I'll buy the relay and strips and will test it with two night lights. Will see what happens.

[yurtle]

My wife walked 30+ miles every morning to fetch water and carry it back home in a HUGE clay pot on her head, before the roosters crowed. I also grew up walking tens of miles each day.

What if your wife had to walk home? Would it kill her? Do you live in a bad neighborhood?

We drove clunker cars for decades, that often left us stranded hundreds (sometimes over 1,000) of miles away from home.