WFCO 8955 LIS upgrade/Lithium battery issue

[Vermilye]

Before you are sure you don't still have a problem, let the batteries get down to 60% - 70% and try to charge them. This will draw the full output of the converter and is typical of situations where you have run on batteries alone for a couple of days.

[DVeePee]

Thanks, that's good advice.

FWIW they were both at about 70% (using a small 3.5a trickle charger) when I separated them and charged them individually. So, that helps me feel somewhat confident that the issue has been identified. I have a friend with the same charger upgrade, charging a 100a Battleborn (1) and he's not had any issues.
I will, however, need to be careful not to switch the battery selector to "Both" if one is well discharged while the other is fully charged. I suspect this would give the BMS's fits, and even cause big problems. Shutting the discharged one off at the breaker will need to be a habit.

When I used this setup before, there were 2 AGMs, and they're not as sensitive to things like this.

[John in Santa Cruz]

fyi, when I run my 2 x 12V 216AH LFP batteries down to like 60%, the PD4655LI outputs about 50 amps at 13.xx volts where XX slowly rises, but it doesn't hit 14.6V until the batteries are nearly fully charged. I measure this with my SmartShunt, and confirmed the voltages with my Fluke DVM. In another thread I remember posting the voltage drops at various points between the PD4655 output and the batteries, 0.25V at 50A is lost on the fuse board just going from the PD4655 output terminal to the battery + terminal on the other side of the 2 x 40A reverse protection fuses.

it doesn't matter, you should not overload the converter, and an LFP battery will suck as many amps as you can push into it until its fully charged.

[CE Vogel]

One thing to consider is cooling. I have three of the same Renogy batteries in my trailer with a Progressive Dynamics converter. When the batteries are low, the cooling fan in the converter runs a lot! My converter is in a large space with lots of air flow, but if your converter is in a confined space it may be overheating and shutting down. The Renogy batteries accept a maximum charge rate of 60 amps, so your two batteries can safely accept 120 amps if they're wired in parallel.

[lostskier]

Hey, this thread showed up at the most opportune time as I'm having a similar problem. I installed a 12v, 270ah Battleborne last fall, replaced the circuit board in the WFCO to lithium, and things seemed to be working well recharging from the solar. Today, I plugged my E19 into shore power, and the battery is not recharging. No amps are being shown to be drawn on the EMS, and my Victron SmartShunt doesn't show any amps either. Again, when the solar is generating enough, I see the amps charging the battery and everything is fine.

When I first plugged into AC, the fan did start up. I think from the GoPower solar controller? Its not running now. My battery was at 72% and is now at 76% and it seemed like it initially was charging. I did not check the amp reading on the EMS when it started up so I don't know if it was drawing current...but almost assume it was.

Any ideas why the battery is not recharging when plugged into shore power? No fuses appear blown in the WFCO. Is there another fuse someplace? The Victron SmartShunt is working.
Thanks, Brian

[lostskier]

I just found the problem. My battery disconnect switch is broken. I jiggled it, the battery started to charge...jiggled it again, and it shut down. Whew...simple replacement.

[CE Vogel]

I looked up the WFCO manual for your converter. It has three protections built in: 1) a variable speed fan for cooling, 2) a current limiting feature to protect it from overheating, and 3) a shutdown mode if the prior two methods fail. It sounds like you have a defective converter board since current limiting doesn't seem to be working since it is shutting down and popping a 60 amp breaker. As others have said, the 60 amp breaker is low, since the WFCO should protect itself, a 80 amp breaker would be better as catastrophic failure and wire protection.

[lostskier]

Thanks Craig...yea, I think its just easy enough to replace the circuit board and move on.
Brian

[DVeePee]

When things would shut down, there was an audible "click". I don't hear very well, so missed the source. I was all focused on the WFCO LiS board and upgrade, or maybe the batteries, or wiring connections.

I finally paid very close attention to the source of the noise and it was coming from the EMS 'brown box'. It has 7 or 8 safety parameters, only one of which is a surge protector. It does low voltage, high voltage, opens, Hz variations, and a few more. When I turned on the house power, I had 122v coming in. When the charger would click on, the voltage would drop to 102-103v. It has a lower end cut off at 104v, so it was shutting the system down until it reset after a while.

I had not suspected the EMS was part of the problem since I'd not changed or disturbed it. It is a 30a unit as well, though they make a 50a version (I'd rather not have to replace this $350 item, but will if necessary).

Turns out 1.) my extension cord to the house was only 14 ga. causing plenty of voltage drop- duh, and 2.) when house power is applied, the water heater shifts to electric mode. Thus, I was trying to charge the battery and heat water, all on a too-small cord = too much voltage drop. Shutting off the breaker to the water heater, and using a 12g extension cord solved the issue. The voltage barely drops now, or stays well about the low end cutoff anyway.

I do have the batteries wired separately to a "1-2-both" selector switch. I can charge the batteries one at a time. They are bluetoothed to my phone, and I can check charge levels and several other factors as well. This is more informative than the Victron shunt, or so it seems.

When in "both" mode the batteries are in parallel.

Anyway, it's been run through a few trial charge/discharges and things are working fine.

[Shon414]

Great news! Good investigative skills. I learned a lot out of this thread. You just made me shelve my magical Pixies theory....

[BobG]

DVP, you mentioned the batteries were 33% and 41% SOC when you received them. If you then connected both in parallel to the 55 amp charger, would the 41% battery then be discharging into the 33% battery? If so, then would it be possible that the 33% battery was receiving too many amps, some from the charger and some from the 41%SOC battery) and shut down?
If the batteries are at a low but equal SOC and connected in parallel to the charger then wouldn't the 55 amp charger be delivering 27.5 amp to each battery (1/2 of 55 amp charger capacity to each battery) which is about half of their allowable charging current?

[Shon414]

This supports BobG post
From what I found on the Topic of connecting 2 different SOC Lithium batteries it does sound like good prac to charge them up separately to same SOC of charge so differential is small before connecting them in parallel

See this post
https://diysolarforum.com/threads/wo...-damage.15962/

Agree / Disagree?

[John in Santa Cruz]

yeah, I fully charged mine separately with the PD4655 before paralleling them, as they arrived with a very low state of charge, like 20%

[John in Santa Cruz]

Originally Posted by lostskier

I just found the problem. My battery disconnect switch is broken. I jiggled it, the battery started to charge...jiggled it again, and it shut down. Whew...simple replacement.

those factory battery disconnect switches can't really handle the 50A+ charging current of a LFP. I replaced mine with a 250A rotary marine disconnect.

[DVeePee]

RE: Batteries in different SOC - I did charge them separately after the initial attempts to charge them both at the same time. I used a small lithium compatible portable charger, and it took a VERY long time. From that point on though, they had a nearly identical SOC (1% difference or so). Still problematic.

And yes, the 55a charger was probably splitting the charge between both batteries when they were in parallel. It was doing 55-60a measured w/ a clamp on ammeter before shutting down.

I'm almost dead certain that the shut-down condition was from voltage drop kicking off the EMS, rather than current demand shutting down the charger. I changed/improved several things in regards to thinking it was the charger, to no avail. Once I paid attention to the EMS, via the small data screen and the "Prior Error" codes, I determined that it was a low voltage problem. Switching to a 12g drop cord basically solved that issue, keeping the voltage incoming above 104v but barely. Then, shutting off the electric option on the water heater made it a non-issue. An engineer buddy helped determine this and confirmed the diagnosis and solution.

All in all, it was a good study in problem solving, and also my tendency to jump to conclusions, assuming the negative and complicated rather than the simple and obvious (Occam's razor).

And finally, RE: the battery switch. I was always of a mind that the ETI choice in battery switch was funky, both in location and lack of substance. I relocated it to a more accessible location, and used a heavy duty rotary style marine version, as might be used on a boat, or a firetruck. No chance of bumping it accidentally and changing position, or overloading it. I like having the option of using one battery with the other in 'reserve'. I do have to be cautious not to switch to "both" when one battery is significantly lower in charge than the other. When they are both fully charged, I can operate them both simultaneously (in parallel) if I want to.

[rubicon327]

Originally Posted by DVeePee

I'm almost dead certain that the shut-down condition was from voltage drop kicking off the EMS, rather than current demand shutting down the charger. I changed/improved several things in regards to thinking it was the charger, to no avail. Once I paid attention to the EMS, via the small data screen and the "Prior Error" codes, I determined that it was a low voltage problem. Switching to a 12g drop cord basically solved that issue, keeping the voltage incoming above 104v but barely. Then, shutting off the electric option on the water heater made it a non-issue. An engineer buddy helped determine this and confirmed the diagnosis and solution.

Good troubleshooting. This is a great reminder for owners that an undersized extension cord with a high load will trip the EMS on low voltage. I've done it. The EMS readout is a great tool for knowing the instantaneous amps that the trailer is drawing...especially if you are on a 15 or 20A circuit at home, small generator, etc. It sounds like you are good to go now with battery monitoring and selector switch. Nice work.

[John in Santa Cruz]

if the two batteries have different rest voltages, the higher voltage battery will try and dump amps into the lower voltage battery. if the volt differenc eis significant, that can be a LOT of amps. even a slight difference of like 0.1 volt in the 13.x range can be quite a lot of current

[Crazypill]

I have the WF-8955PEC-B-LiS -- this board adds a toggle for Lithium vs LA/AGM right? Where is the switch, I think mine may be set to LA/AGM because it's not fully charging my lithium battery bank with a max charge voltage of 14.7, I would like to set it ideally to 14.5. Can anyone share a photo or describe how to access the switch? Thank you.

[DVeePee]

On the LiS circuit board the switch is a very small red rectangular thing, on the left side of the board, below the negative terminal blocks. It might be 1/4" long, and 1/8" inch wide, that's being generous.

I understand that newer versions of the WFCO 8900 series unit are "smart" inasmuch as they can determine the needs of the battery used, and thus do not have a switch. A friend of mine just got a new Escape, and it has such a unit w/o a switch.

[Crazypill]

Would that be on the left side of the 12v circuit board? Mine is a 2022 I just took delivery of within the last few weeks, so it's likely to not have the switch.