No battery power / charging issue

RocknRoll · 03-06-2021, 01:39 PM

Hi everyone, I hope that someone can help me diagnose what's going with my rig.

Background: A few months ago I replaced my (2) 6V GC batteries with a Valence LifeP04. Simultaneously, I replaced the Charger/Converter (WFCO WF-8950L2-MBA). Everything went without a hitch. I was able to run off the battery and recharge when plugged into shore power.

I didn't pay attention to my battery voltage for a few weeks as it seemed to maintain 13.1V just fine. However, when I checked a few days ago, the voltage was down to 11V. I plugged my rig into 110/15A shore power and the Voltage went to 13.5V and eventually settled down at 13.1. I thought that this was strange as prior to this, It would perform a bulk charge to 14.5 and settle down to 13.3 but brushed it off. The weather was warmer so I decided to test my AC using a generator I just purchased. I disconnected shore power and plugged in the generator. It ran the AC just fine, shut everything down and was feeling pretty good… until today.

The lack of a bulk charge to 14.5 bothered me and decided to go out and check it out. The voltage was under 13 and when I went inside the rig, the lights did not come on. There was no power to anything except for the tongue jack. The disconnect switch has continuity

I took off the charger panel and there was no voltage to the DC board. Basically, everything is dead as a doornail

When connected to shore power:
Battery no longer charges via 110/15A shore power
DC board reads 14.6V.
The slide works

I can't remember if I disconnected the battery prior to this. Could running the generator somehow fry the converter/charger? I'm feeling really stupid and discouraged right now.

Thanks in advance for any advice you can offer.

Winterbagoal · 03-06-2021, 04:31 PM

What model/Ah capacity Valence battery did you buy? From where? New or used (I see a few for sale, some used, on eBay)?

al1florida · 03-06-2021, 06:02 PM

Are you using a multimeter to measure the voltage at the battery, if not what is monitoring the voltage?

You last statement seems to state that you don't have any 12V from the battery, just 0 volts when not on shore power or generator. Is that correct?

Lithium batteries generally have a low voltage cut off built into their BMS to keep from destroying the battery.

If your battery tripped the low voltage cut off there may be a special procedure to restart the battery so it will accept a charge. Do you have a manual detailing what to do if the battery enters a low voltage protection state?

RocknRoll · 03-06-2021, 06:34 PM

Thanks so much for the quick replies. Much appreciated!

Quote:

Originally Posted by Winterbagoal

What model/Ah capacity Valence battery did you buy? From where? New or used (I see a few for sale, some used, on eBay)?

I purchased a U27-12XP from ebay used. Only had 12 charge cycles on it. Has been working great until recently. I don't think it's the battery, but possibly the charger/converter.

Quote:

Originally Posted by al1florida

Are you using a multimeter to measure the voltage at the battery, if not what is monitoring the voltage?

You last statement seems to state that you don't have any 12V from the battery, just 0 volts when not on shore power or generator. Is that correct?

Lithium batteries generally have a low voltage cut off built into their BMS to keep from destroying the battery.

If your battery tripped the low voltage cut off there may be a special procedure to restart the battery so it will accept a charge. Do you have a manual detailing what to do if the battery enters a low voltage protection state?

I don't have a battery monitor right now. I do have a 100/30 Victron Solar Controller that monitors the voltage for now. I'm also using a multimeter to test continuity and voltage at the DC charge board.

I get 13V from the battery. As I mentioned, the tongue jack works which is a separate wire from the battery.

Good question on the low voltage cut-off, as according to the thread below, there isn't one on this battery and anything below 10V will damage it.

https://www.t6forum.com/threads/vale...done-it.22182/

One thing I forgot to mention is that I moved the battery from the tongue to inside the pass-thru a week ago. Everything seemed to be ok, however I never installed an inline fuse (there wasn't one there before). I was careful about using the battery disconnect but who knows. Dumb mistake.

al1florida · 03-07-2021, 06:15 AM

Quote:

Originally Posted by RocknRoll

Thanks so much for the quick replies. Much appreciated!

I purchased a U27-12XP from ebay used. Only had 12 charge cycles on it. Has been working great until recently. I don't think it's the battery, but possibly the charger/converter.

I don't have a battery monitor right now. I do have a 100/30 Victron Solar Controller that monitors the voltage for now. I'm also using a multimeter to test continuity and voltage at the DC charge board.

I get 13V from the battery. As I mentioned, the tongue jack works which is a separate wire from the battery.

Good question on the low voltage cut-off, as according to the thread below, there isn't one on this battery and anything below 10V will damage it.

https://www.t6forum.com/threads/vale...done-it.22182/

One thing I forgot to mention is that I moved the battery from the tongue to inside the pass-thru a week ago. Everything seemed to be ok, however I never installed an inline fuse (there wasn't one there before). I was careful about using the battery disconnect but who knows. Dumb mistake.

If you are reading 13.0V at the battery and you are connected to shore power or generator power then your battery is OK. A little low on SOC (State Of Charge) at 30%.

al1florida · 03-07-2021, 06:24 AM

Quote:

Originally Posted by RocknRoll

Hi everyone, I hope that someone can help me diagnose what's going with my rig.

Background: A few months ago I replaced my (2) 6V GC batteries with a Valence LifeP04. Simultaneously, I replaced the Charger/Converter (WFCO WF-8950L2-MBA). Everything went without a hitch. I was able to run off the battery and recharge when plugged into shore power.

I didn't pay attention to my battery voltage for a few weeks as it seemed to maintain 13.1V just fine. However, when I checked a few days ago, the voltage was down to 11V. I plugged my rig into 110/15A shore power and the Voltage went to 13.5V and eventually settled down at 13.1. I thought that this was strange as prior to this, It would perform a bulk charge to 14.5 and settle down to 13.3 but brushed it off. The weather was warmer so I decided to test my AC using a generator I just purchased. I disconnected shore power and plugged in the generator. It ran the AC just fine, shut everything down and was feeling pretty good… until today.

The lack of a bulk charge to 14.5 bothered me and decided to go out and check it out. The voltage was under 13 and when I went inside the rig, the lights did not come on. There was no power to anything except for the tongue jack. The disconnect switch has continuity

I took off the charger panel and there was no voltage to the DC board. Basically, everything is dead as a doornail

When connected to shore power:
Battery no longer charges via 110/15A shore power
DC board reads 14.6V.
The slide works

I can't remember if I disconnected the battery prior to this. Could running the generator somehow fry the converter/charger? I'm feeling really stupid and discouraged right now.

Thanks in advance for any advice you can offer.

It seems you have 13.0V at the battery and the slide & tongue jack work.

Since you have 14.6V at the DC board when on shore power, that should indicate the charger is working.

I think you have a blown fuse or disconnected wire from the battery to the charger or DC board since you don't have battery voltage when disconnected from shore power.

RocknRoll · 03-07-2021, 06:57 AM

Quote:

Originally Posted by al1florida

It seems you have 13.0V at the battery and the slide & tongue jack work.

Since you have 14.6V at the DC board when on shore power, that should indicate the charger is working.

I think you have a blown fuse or disconnected wire from the battery to the charger or DC board since you don't have battery voltage when disconnected from shore power.

Thank you Al, that was my thought also. I've checked all of the fuses and have checked wire up to the disconnect. I'll double check again.

Marine359 · 03-07-2021, 07:43 AM

Slide and jack are working because they aren’t wired through the disconnect switch. When you moved the battery into the pass-thru, I presume you took the cables which were connected to the tongue battery and stuffed them up through the existing entry where the dc loom wires go under the coach floor. Since battery will not charge from ac circuit, this tells me it is likely the problem is that dc is not moving between battery and breaker panel So, either the disconnect switch, or damaged/shorted battery cables. You may want to check the routing of the battery cables to make sure they are not being grounding entering the pass-thru. And that you have a good firm connection of the cables to the battery. After connecting to battery, open switch and measure voltage on both sides of the switch. If you have voltage on both sides of the switch, you should have voltage entering the breaker panel. Having just completed a pass-thru LiFePo4 install, this is where I would begin sleuthing.

As an aside, if you are using the stock 2108 charger, it has the wrong charging profile for LiFePo4. You should unwire it from the breaker panel, and replace with a charger with LiFePo4 charging specs.

RocknRoll · 03-07-2021, 09:47 AM

Quote:

Originally Posted by Marine359

Slide and jack are working because they aren’t wired through the disconnect switch. When you moved the battery into the pass-thru, I presume you took the cables which were connected to the tongue battery and stuffed them up through the existing entry where the dc loom wires go under the coach floor. Since battery will not charge from ac circuit, this tells me it is likely the problem is that dc is not moving between battery and breaker panel So, either the disconnect switch, or damaged/shorted battery cables. You may want to check the routing of the battery cables to make sure they are not being grounding entering the pass-thru. And that you have a good firm connection of the cables to the battery. After connecting to battery, open switch and measure voltage on both sides of the switch. If you have voltage on both sides of the switch, you should have voltage entering the breaker panel. Having just completed a pass-thru LiFePo4 install, this is where I would begin sleuthing.

As an aside, if you are using the stock 2108 charger, it has the wrong charging profile for LiFePo4. You should unwire it from the breaker panel, and replace with a charger with LiFePo4 charging specs.

That makes a lot of sense Jim, thanks! I drilled a hole directly thru the pass thru floor and fed the all wires straight up. Was pretty straightforward.

The slide does NOT work except on shore power. The tongue jack does, probably because it's a separate wire.

Forgive my ignorance, but how does one correctly check the voltage on both sides of the disconnect? I took one lead on either side of the switch when on and the other on the negative on the battery. Is that correct? If so, I get zero voltage.

I did switch out the charger to a Lithium profile when I replaced the battery a month ago and worked fine.

Marine359 · 03-07-2021, 09:56 AM

If you have a clamp style multimeter, you can put the clamp one at a time around the wire bundles on either side of the switch. Switch on. If you’re reading 13v or higher on one side, but not the other, then the problem is definitely the switch. If you’re not able to see voltage on either side, the problem is the battery cable. If you’re reading voltage on both sides of the switch, the problem is the breaker panel. In that case, check fuses and reset all breakers. If that doesn’t work, I do hara-kiri.��

RocknRoll · 03-20-2021, 06:01 AM

I finally got around to tackling this again yesterday. Come to find out, one of the covered bus bar connections underneath the tongue was not fully tightened.

With all of the changes I have done including the battery swap / relocation to the pass-thru and charger controller, it didn't occur to me it might be something simple. I guess the good news out of all of this is I'm learning about the intricacies of this "hobby".

Thanks again to everyone who responded. It is greatly appreciated!