Once Again - LIthium Battery Install?

This (20 amp AC to DC charger for lithium batteries) looks like a good solution to shore power charging of LiFePO4 batteries, seems better to me that a work-around with the battery to battery (DC-DC) charger and the problem of the D+ ignition connection requirement for the Renogy DC-DC charger.

Thoughts?
 
Pat Anderson":2r046qz2 said:
This (20 amp AC to DC charger for lithium batteries) looks like a good solution to shore power charging of LiFePO4 batteries, seems better to me that a work-around with the battery to battery (DC-DC) charger and the problem of the D+ ignition connection requirement for the Renogy DC-DC charger.

Thoughts?
Click to expand...

That charger looks like it probably won't last long in a salty marine environment.
 
I have a 10 amp charager 120 V mains power AC to 10 amp DC 14.6 volts. One feature I like is that it has as a screen showing state of charge, volts out, amps out.

I got rid of the clamps--and put in Anderson Power Pole 30 amp connectors on the battery and the charger.

I would either hard wire or put a more robust connector. You don't want that out in the weather!
 
ssobol":2o397ftz said:
That charger looks like it probably won't last long in a salty marine environment.
Click to expand...

That charger being a stand alone "shore power" charger would only be used in my driveway or garage plugged into an extension cord. In the salty marine environment, the charging will come from the alternator to starting battery then to the lithium battery through the DC-DC charger and from the solar panels through the charge controller then directly to the lithium battery. The alternative would be to upgrade the Guest 10-10 on board charger. This stand alone 20 amp charger seems like it would be worth the ~$100 to me.
 
Anyway, back to the Renogy DC-DC charger and LiFePO4 battery. The DC-DC charger is the 40 amp version.

I hooked it all up to bench test. I am confident all the connections are correct (i.e., the positive and negative are clearly marked for the input to and output from the charger, and I triple checked. I am using a fully charged Group 31 AGM battery connected to an automotive charger in lieu of the "starting battery" and the charger output is connected to the lithium battery. The "engine on" function is a wire from the positive lug of the AGM battery to the D+ connector on the DC-DC charger. All wiring is 10 gauge (ideally it would be 8 or 6 but I did not have any, for the install on the boat I will use larger wire). The charger powers on and starts up - BUT the status LED is red, which indicates a fault.

It could be the DIP switches I suppose. Switch 5 is up, which is "OFF," which selects lithium. The other four switches select charging voltage, with choices ranging from 14.0 to 14.6. I have it set for 14.6, which is all the other switches "ON," which is down. I COULD try all the other charging voltages I suppose. I did not find any guidance in the battery manual.

Any ideas on what else the fault could be (this question is directed to people who have a correctly functioning lithium battery or batteries and a DC-DC charger installed). Boris, you have the 20 amp version of the same DC-DC charger installed, what are your DIP switch settings?

Thanks!

 
thataway":19q9nrkr said:
I have a 10 amp charager 120 V mains power AC to 10 amp DC 14.6 volts. One feature I like is that it has as a screen showing state of charge, volts out, amps out.

I got rid of the clamps--and put in Anderson Power Pole 30 amp connectors on the battery and the charger.

I would either hard wire or put a more robust connector. You don't want that out in the weather!
Click to expand...

What is the brand and model of your AC to DC 14.5 charger? The screen seems like a good feature but if I EVER get my LiFePO4 activated (which is by the initial charge, which at the moment I seem unable to do), that same data will show up on my Renogy phone app via bluetooth from the battery itself.
 
Well, Pat, sorry to be late to the party, but I've been painting the bottom of das boot and surviving Fathers Day. Amazing how many fathers we have in the family now.

So, I've checked your latest schematic and it looks good. I assume that on the bench, you've not connected the MPPT. Given that, it looks like the wiring diagram for my installation. I'm using a 20 amp version of your 40 amp charger. There is one difference in that I power the "ignition on" port with power from the Li battery. If the FLA battery goes too low during the charge it may shut the charger off. Your switches are set as the manual and my charger. I assume that the starter (FLA) battery is being continuously charged during the Li battery charge.

From the manual's troubleshooting section.
1.Double check that your wiring is correct with a multi-meter and
that the battery levels are suitable within the operating voltage
range.
1.The DC-DC is experiencing an internal short circuit due to an
imbalance between its input and output circuits. Restart the DC-DC by disconnecting the input/output and then reconnect.
The error will clear automatically upon a successful restart. If
issues continue with a permanent red led, then contact support
to address the previous troubleshooting step.

Now back to my opinion

All I can think of is to take a voltmeter and check the input and output power and the ignition on switch for 12 Vdc. If you've got 12 v on both sides and to the switch, you should be OK. Make sure that the grounds are common on both sides of the charger with the resistance function. Renogy sells a common ground charger as well as (I assume) a separate ground. When the FLA battery is charging the Li battery, check the input voltage to make sure it doesn't go below 8 Vdc and shut off the DC-DC charger. How are the cables connected to the Li battery. I had to order 8 mm studs to guarantee the cables were tight.

40 amps is a lot to draw continuously from a FLA battery. I know they're good for >200 A, but you're having trouble. Try connecting the 1/2 rate port to 12 Vdc as discussed in the manual . 20 A is a good place to start.

The circuit is simple. If everything is connect correctly and the FLA battery is charged, the switches are closed, the chargeer should charge. Chack all the voltages with a voltmeter.

Boris
 
Salmon Fisher":1wga5kvf said:
Pat Anderson,

How did your Lithium Battery installation go? What was the performance like?
Click to expand...

The project is on the shelf for the time being. The lithium battery is in the truck camper right now with a Renogy 110 volt charger to power my CPAP!
 
Pat Anderson":10jeqv0i said:
If I have correctly understood Bob's post, ALL the normal charging sources (alternator, solar, and on-board Guest or other shore power charger) go directly to the FLA starting battery. The VSR is now out of the picture. The FLA starting battery is kind of a buffer for all charging sources. The FLA starting battery goes to the DC to DC charger input connectors. The DC to DC charger output connectors go to the LiO posts, and that charges the LiO battery.
Click to expand...
Personally I would not route all the charging sources through the start battery for the following reasons:
1) With the setup you've described you can only charge your Li battery through the limited output of the DC to DC charger. This puts a lot of wear on the start battery since you are essentially forcing all house needs to go through the start battery.
2) You are limited to charging the Li battery at the rate the DC to DC charger can provide. If you provide the Li battery with its own shore power charger, you can charge it much faster when connected to shore power.
3) The above scenario may require a lot of heavy wiring to go back to the starter battery, if your house battery is located forward.

In my design the start battery is charged by the alternator and a shore power charger that is dedicated to the start battery. In an emergency, I can charge it with my generator via the shore power connector. The Li house battery is charged when underway by the DC to DC charger from the start battery. It is also charged by solar and a dedicated shore power charger, both of which are located near the house battery.
 
Have you considered what will happen if the Li battery shuts down? New ABYC guidelines recommend, but do not require, that the battery BMS provides an audible and/or visual signal to warn of imminent shutdown.

I plan to use a battery that provides such a signal (Victron Smart Battery for example) to activate both a visual and an audible alarm. I'm also incorporating a battery switch that I can use to switch all house loads (which include components critical to navigation) over to the start battery, should the house battery shut down.
 
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