Unanticipated LiFePo issue

[GlasNav]

Had Keystone install the basic Zamp Solar system, which I immediately upgraded to a three panel system upon receiving the trailer. Additionally, replaced the battery box and added two LiFePo 100AH batteries in parallel, as well as replacing the stock WFCO converter with a WF-9800LiS capable of handling the LiFePo batteries. (BTW: reaching in and working behind the distribution panel to swap out the converter is a pain in the butt.)
The system worked flawlessly for a year, until we moved and purchased a house with an unattached three bay shop, the center being a high bay which accommodates the trailer nicely. Our own enclosed storage, a RVers dream!
However, after the trailer was tucked away for three months and on shore power with the internal battery heater circuits energized the unexpected occurred in December when I went to pull the trailer out. There wasn't enough power left in the batteries to operate the jacks. I plugged the towing harness into the truck and was able operate the jacks and move the trailer. Due to inclement weather and limited sunshine it took a couple of days for the batteries to fully recover.
What I overlooked is the fact that the charger - converter outputs in "Bulk Mode" at 14.6VDC for only 1 - 4 hours depending on your settings after it has been energized. The converter then reduces to 13.6 volts which didn't charge the LiFePo batteries.
My work around for the covered / enclosed storage is that I'm installing a 7 day timer rated at 50 AMPS and will have it cycle a couple of times a week to activate bulk mode and keep the batteries charged.
Thought others may find this useful in avoiding a duh moment!

[bobbecky]

Did you switch that converter to lithium mode? If in lithium mode it will only charge at the 14.4 volts. You had it in the LA mode and that is why it was changing voltages.

[GlasNav]

I do have the jumper installed for lithium and it outputs 14.6 for four hours then drops to 13.6.
The manual also states that it only charges in bulk mode for up to 4 hours then drops to absorption mode at 13.6, no other settings other than "simple cycling power will reset timers" for larger battery banks greater than 200AH.

[jxnbbl]

I would call the converter support...this does not "sound right". Maybe there is a test to confirm the jumper setting?

[GlasNav]

There is only one jumper option on this model converter, [no jumper] is for lead acid batteries, [jumper] is for Lithium batteries which increases the voltage, and it does. My issue is that the LiFePo batteries lose their charge over time during the winter with their internal heaters energized while the converter is in absorption mode at 13.6 volts and no sunlight on the panels with the trailer inside the shop.

[jxnbbl]

Since you have power to the trailer location, why don't you just put a trickle/maintenance charger directly on the battery. I have two different versions of the NOCO Genius that I use in two locations (one for 4 batteries and one for 2 batteries). They have quick connect wiring so it would be an easy transition from hooking them up.

[Stircrazy]

13.6V is the resting voltage for fully charged on a LifePO4 battery. You might not get to 100% right away but if you let it sit for a few days at 13.6 then unplug it and plug it back in so it goes into boost it will bring them to 100%. most of the people I know are looking for adjustable two stage so it will never charge it over 90% to increase the cycle life.

[NH_Bulldog]

Up here in the Northern states, we just pull the batteries in the winter and set them on a bench in a heated area. No need to keep the battery heaters energized and a battery tender keeps them topped off and ready to go.

[firestation12]

Originally Posted by GlasNav

Had Keystone install the basic Zamp Solar system, which I immediately upgraded to a three panel system upon receiving the trailer. Additionally, replaced the battery box and added two LiFePo 100AH batteries in parallel, as well as replacing the stock WFCO converter with a WF-9800LiS capable of handling the LiFePo batteries. (BTW: reaching in and working behind the distribution panel to swap out the converter is a pain in the butt.)
The system worked flawlessly for a year, until we moved and purchased a house with an unattached three bay shop, the center being a high bay which accommodates the trailer nicely. Our own enclosed storage, a RVers dream!
However, after the trailer was tucked away for three months and on shore power with the internal battery heater circuits energized the unexpected occurred in December when I went to pull the trailer out. There wasn't enough power left in the batteries to operate the jacks. I plugged the towing harness into the truck and was able operate the jacks and move the trailer. Due to inclement weather and limited sunshine it took a couple of days for the batteries to fully recover.
What I overlooked is the fact that the charger - converter outputs in "Bulk Mode" at 14.6VDC for only 1 - 4 hours depending on your settings after it has been energized. The converter then reduces to 13.6 volts which didn't charge the LiFePo batteries.
My work around for the covered / enclosed storage is that I'm installing a 7 day timer rated at 50 AMPS and will have it cycle a couple of times a week to activate bulk mode and keep the batteries charged.
Thought others may find this useful in avoiding a duh moment!

O.K. Something isn’t adding up in this description of the problem. 13.6 volts is certainly enough to charge the lithium batteries to approximately 90% of a full charge of the 2 lithium batteries. Each cell of a lithium battery produces 3.3 volts at full charge. 4 cells at 3.3 each equals 13.2 volts. Since 13.6V is higher than 13.2V, the batteries are being adequately charged. Your WF-9800 description doesn’t tell us the amp rating. For example, WF-9835 (35 amps) or WF-9875 (75 amps) indicates the amps it can deliver at 13.6 volts when not in the bulk mode. Also the bulk charge lasting for 1-4 hours is not unusual. If you have a lithium capable solar controller between the roof panels and the 2 lithium batteries, it essentially runs the same profile as your WFCO converter. Obviously since the trailer is parked inside, there is no charging taking place from the solar portion of your system. Those 2 batteries were zero’d out because the heaters were drawing current and there wasn’t any charging taking place from your WFCO converter. I have successfully used the standard OEM voltage converter as a backup to my 600 watts of solar feeding 560ah of lithium batteries. I say backup because I keep the circuit breaker turned off to the voltage converter almost exclusively unless…like for barn storage. Someone suggested using a trickle charger to maintain the batteries. I wouldn’t advise that during winter storage. The internal heaters of 2 batteries may consume than a 1-2 amp trickle charger would provide. The problem you have is, there isn’t any charging taking place to the 2 batteries. As they say in China “Sum Ting Wong”.

[GlasNav]

The power of this forum once again shines!
I was so darned focused on making what's installed work, this simple alternative sure beats wiring in a 50AMP 7 day timer on the shore power circuit to trick the existing converter - charger.
Looking at the NOCO Genius 10Amp charger that is capable of supporting over 200AH. Will use this and shut off the converter while inside the shop.
Once again, thank you to all that have replied.

[NH_Bulldog]

The heater circuits on the batteries need to be engaged to allow them to automatically activate and deactivate as needed (a connection between the heating terminal post and the battery positive needs to be in place). Once activated, they come on at anything below 35°F and turn off when ambient temperature exceeds 45°F. You can disconnect the heating circuit if desired. Setting them on a bench in a heated area will not cause the heaters to activate and a battery tender will easily maintain them.

Most LiFePo battery manufacturers for winter storage suggest physically disconnecting from the terminals to avoid parasitic loads. In this manner, they can safely be stored to as low as -15°F. When you are ready to use them, reconnect the terminals and let the heaters do their thing and the batteries will charge once conditions are met.

[firestation12]

Originally Posted by GlasNav

The power of this forum once again shines!
I was so darned focused on making what's installed work, this simple alternative sure beats wiring in a 50AMP 7 day timer on the shore power circuit to trick the existing converter - charger.
Looking at the NOCO Genius 10Amp charger that is capable of supporting over 200AH. Will use this and shut off the converter while inside the shop.
Once again, thank you to all that have replied.

The NOCO product will provide a temporary work around, BUT you still need to figure out why the WFCO converter isn’t charging. It not only should charge but also provide enough amps to operate everything that is 12 volts in the trailer. Obviously that isn’t happening if the batteries are dead.

[GlasNav]

I would like it to function correctly, but getting into where Keystone squeezed the components is impossible without dismantling the bedroom. The solar controller is mounted in the small pass thru on the forward bulkhead and the disconnect switch for the inverter and the inverter are mounted to the underside of the bed support, while the converter 55AMP is located on the floor behind the distribution panel under the stove.
Unless you have some insight as to what is open or if there is a diode some where, I going to entertain the work around.

[GlasNav]

One possibility might be the main disconnect switch on the tongue. It appears wedged into place during assembly to the point that the cover doesn't seat correctly. Could something in there be open and only the solar is getting to the batteries???

[firestation12]

Originally Posted by GlasNav

One possibility might be the main disconnect switch on the tongue. It appears wedged into place during assembly to the point that the cover doesn't seat correctly. Could something in there be open and only the solar is getting to the batteries???

A photo of the “wedged in” main switch would be helpful. I’m not mentally picturing a “cover”.

[GlasNav]

This is the disconnect on the tongue. I didn't alter it when installing the battery box. The bottom of the switch box housing rests on the battery tray supports not allowing for the cover to seat correctly. [From factory this way] That's why I have some duct tape over the cover lip to minimize any water intrusion. I did remove the cover when wiring in the new batteries because the wire route required a longer lead. Really don't like the stacked connectors that I saw inside.

[snoobler]

This isn't a charger issue. This is ultimately a wiring issue. There is too much voltage drop between the charger and the battery. 1-4 hr @ 14.6 AT the battery terminals is more than enough time to fully charge them.

There is zero reason to keep LFP batteries at full charge. In fact, it is detrimental to do so. They degrade when held at full charge. Doubly so if at high temperature. Less so at low temperature.

If they are in an application where they are sitting around unused most of the time, this is the least ideal situation for them. Might as well have bought AGM. AGM have a lower total cost of ownership per kWh delivered when infrequently cycled. LFP only represents the best value when it it cycled frequently.

NOCO is very over-confident by calling their chargers "genius." I would call them "pretty smart," but the only genius charger is one that allows you to specify your own charge voltages, because there are lots of different absorption/float voltages out there based on manufacturer's recommendation.

The converter's default behavior is fine. A LFP battery sitting at 13.4V+ is either fully charged or darn close.

If heated batteries are engaging the heater without a charge source, they are defective or badly designed. The heaters should not draw from the battery. The heaters should only draw from the charge source.

[firestation12]

Originally Posted by snoobler

This isn't a charger issue. This is ultimately a wiring issue. There is too much voltage drop between the charger and the battery. 1-4 hr @ 14.6 AT the battery terminals is more than enough time to fully charge them.

There is zero reason to keep LFP batteries at full charge. In fact, it is detrimental to do so. They degrade when held at full charge. Doubly so if at high temperature. Less so at low temperature.

If they are in an application where they are sitting around unused most of the time, this is the least ideal situation for them. Might as well have bought AGM. AGM have a lower total cost of ownership per kWh delivered when infrequently cycled. LFP only represents the best value when it it cycled frequently.

NOCO is very over-confident by calling their chargers "genius." I would call them "pretty smart," but the only genius charger is one that allows you to specify your own charge voltages, because there are lots of different absorption/float voltages out there based on manufacturer's recommendation.

The converter's default behavior is fine. A LFP battery sitting at 13.4V+ is either fully charged or darn close.

If heated batteries are engaging the heater without a charge source, they are defective or badly designed. The heaters should not draw from the battery. The heaters should only draw from the charge source.

I’m not seeing a smoking gun that puts the the blame on the wiring as the sole reason the batteries are dead. The OP stated that the camper batteries stayed charged for a full year while outside receiving solar charging from the 3 panels. It wasn’t until the camper was moved inside his new barn that the batteries went dead. Actually it’s likely the BMS prevented the battery from fully discharging. The new WFCO charge converter should have taken over for the lack of solar power. There hasn’t been enough disclosure to say, “this is ultimately a wiring issue”. Granted it may turn out to be the OP’s wiring, but whatever caused the batteries to discharge is, a lack of charging current reaching them for any number of reasons. A few other comments: internally heated LiFePo4 batteries do not have a separate circuit to supply the heating pad. Should the battery fail to get a charging current, the BMS
will eventually disconnect the battery before it totally discharges. Likewise, the BMS prevents the battery from being overcharged. It is correct that high temps affect longevity (but I’ve not seen any literature that claims “doubly so”. I would agree that charging to slightly less than 100% can increase longevity. While all these pontificated dire warnings you list may or may not have some value, the fact is, they have nothing to do with helping the OP solve his battery problem. BTW, I would never claim an AGM battery represents a better value than a LiFePo4 battery. Lithium batteries fare extremely well “just sitting around unused most of the time” unlike AGM or lead acid.

[GlasNav]

Originally Posted by firestation12

The NOCO product will provide a temporary work around, BUT you still need to figure out why the WFCO converter isn’t charging. It not only should charge but also provide enough amps to operate everything that is 12 volts in the trailer. Obviously that isn’t happening if the batteries are dead.

We will have the opportunity next week to put the trailer back in the shop and out of sunlight. I'm considering disconnecting the batteries, energizing the converter - charger and check the cables in the battery box to see if the charging voltage is getting to the batteries.

FireStation12: Thank you for spurring me on with positive insight to do what's right and not accept or pursue a shade tree solution.

[GlasNav]

Just realized that the entire issue "might" be related to the [Giggy Box] battery disconnect box. I will open it up and see if the charger is actually connected to terminal 17 as indicated on the wiring diagram in Keystone's video.
If it was overlooked during assembly (As several things were during the Covid build of this unit) this could be the issue as the converter could run everything thru its connection with the distribution panel, and the batteries also feed the distribution panel. But, unless the voltage is feeding back through the equipment that may be switched on, it wouldn't reach the batteries with sufficient voltage and amperage to charge them.

Please consider this theory and let me know your thoughts.
It could be I've only been charging with solar since receiving the unit! The voltage readings I've reported are those displayed on the In Command display.

Time for me to properly troubleshoot and also install the Victron shunt and system display that are still in their boxes for a year and a half.