House battery question

[Hammertime]

So of course today we are making a trip from NC to NY and we noticed the house battery was very low. So low that we could not start the generator. I hooked my 2014 AI to shore power in order to run the genset. My plan is to let it run for an hour but this has never happened before and I'm worried the battery may not be holding a charge. Last night we had it hooked to shore power for an hour but maybe that's nothing. We typically drive it so much that we simply run the genset 1 hour a month and we are fine. Our last road trip was over a month ago so it has not seen too much action lately. I'm hoping that this is normal and that you all may have tips for me to get things charged up so that losing battery power is not a concern the whole trip. Or maybe there have been red flags that i should have been seeing? Or somehow a setting got changed and it no longer charges? I did have warranty work recently done. It wasn't related to the battery but the dealership always seems puzzled on how to work our system so perhaps they messed with something. Anyhow, I know I have a lot to learn regarding the battery and I appreciate your input.

[LB_3]

1 hour on the charger probably won't do much for you. Lead acid batteries have too high of an internal resistance to charge reeally fast.

What is the current voltage of the battery with nothing turned on?

Rule of thumb:
100% - >13v
75% - 12.6v
50% - 12.2v
25% - 11.8v
0% - <11.4v

[ColoradoLady]

When I first brought mine home in April, I did not know to turn the battery disconnect switch off to avoid trickle discharge of batteries. I was able to "jump start" the generator by starting the engine, and run it for 2-3 minutes, and, while still running, start the generator. It started right up and I let it run, turned off engine. Gen ran for 2-3 hrs and brought the battery up to par. I hope this helps.

[Mcrid]

Sitting for a month will discharge the house batteries from parasitic draw. It really needs to stay plugged up and an hour will not do it. You can get to 80% quickly. The last 20% will take awhile. One this to check is if you have the Magnum inverter/charger that it is set to charge at 100% output. That will speed the process. I make this recommendation on the assumption you have the Lifeline 24T batteries and M 1000 watt unit. If may want to do some more research.

[73shark]

I'm going to say something is wrong assuming that everything is turned off as the 100W solar panel should maintain your Lifetime AGM batteries at 100%. My 50W panel keeps mine at 100% in the winter w/ some overcast days.

[UKDUDE]

If the batteries have been allowed to discharge below 50% more than a couple of times, even with the parasitic draw that can occur when the disconnect switch is in use, then they are likely ruined and no matter how long you charge them, they will never hold a full charge. It's a fact of life with all RVs that you have to baby the batteries all the time.


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[Mcrid]

Originally Posted by UKDUDE

If the batteries have been allowed to discharge below 50% more than a couple of times, even with the parasitic draw that can occur when the disconnect switch is in use, then they are likely ruined and no matter how long you charge them, they will never hold a full charge. It's a fact of life with all RVs that you have to baby the batteries all the time.


Sent from my iPhone using Airstream Forums

Below is the Lifeline technical manual. It is true you reduce the life of their battery on repeated excessive discharge, but I wouldn't conclude they are ruined. You can equalize and regain performance.

http://lifelineb.wpengine.com/wp-con.../12/manual.pdf

[UKDUDE]

Originally Posted by Mcrider

Below is the Lifeline technical manual. It is true you reduce the life of their battery on repeated excessive discharge, but I wouldn't conclude they are ruined. You can equalize and regain performance.

http://lifelineb.wpengine.com/wp-con.../12/manual.pdf

That's what it says it the manual, but I would dispute that from my own experience. Equalizing doesn't help if they've been discharged more than a couple of times.

[lewster]

From my experience, applying a 'conditioning charge' as Lifeline calls their controlled over charge, often does little to restore the batteries' capacity.

Part of the problem lies with the charger being used. To properly apply a conditioning charge, you really need a lab grade DC power supply.

I have one (needed for initially charging lithium cells to operating voltages) but even with that, I have never been able to fully restore the capacity of a Lifeline.

Best to keep them at 50% or above. Greater discharge levels will not impact your capacity IF they are fully and completely recharged soon after the deep discharge.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
ABYC Certified Master Marine Electrician
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center*AMS Lithium Batteries
Lifeline AGM Batteries**Magnum Inverters***Victron Energy Components
541-490-6357

[LB_3]

In lead acid batteries there are usually multiple cells. Each cell consists of a lead plates on the anode (neg side) and lead oxide plates on the cathode (pos side). When you dischatge a battery the sulphuric acid reacts with the plates converting the surface of each plate into lead sulphate. During this reaction electrons are released from the cathode into the acid solution and these ions travel to the anode where they complete the reaction.

The reaction is effectively complete when the sulphuric acid is converted to water and both anode and cathode surfaces are covered in lead sulphate.

The biggest danger with running a lead acid battery down is that if the individual cells are are not in balance, one cell will get depleted well before the others. If this happens while the other cells are still discharging, the discharge current will become a charging current in the depleted cell reversing the anode and cathode. Lead oxide will now be formed on the plate that should be pure lead and visa versa. Once a cell is reversed, the battery is irrecoverable.

To prevent this, cells should be balanced periodically. This is done with the 'conditioning' charge. As Lew noted, this is an overcharge of the battery. Once the first cell is fully charged, it boils until all the other batteries catch up. It's not really boiling, electrolysis just separates the hydrogen and oxygen from the water forming bubbles on the plates. These bubbles are liberated in flooded batteries and water must be added to replace what is lost. In sealed batteries, they recombine back into water when they come in contact with each other.

There are other risks with discharging lead acid batteries. A car battery that needs to provide a high current for a short period will have spongy plates that maximize surface area for max 'cold cranking amps'. Repeated deep discharges will slowly alter the physical structure of the spongy plates reducing the surface area and reducing the available cranking amps below what it takes to start your vehicle. Deep cycle batteries like our Lifelines, have much heavier plates and aren't as susceptible to this problem.

The lead sulphate that forms on the plates when batteries are discharged has a tendency to crystallize if left for too long. This can reduce the potential to reverse the chemical reactions with a charging current so it is best to not let a discharged battery stay discharged for too long. This lead sulphate also has a high resistance so repeatedly discharging deep cycle batteries below 50% leads reduced battery performance. The bubbling on the plates caused by a periodic 'conditioning' charge can be used to loosen up the lead sulphate scaling to slow some of the cumulative effects of sulphating batteries.

Well, all that's what I've learned from the armchair battery experts and keyboard warriors on the interwebs. Your mileage may vary.

[lewster]

Not bad at all!!!!! Good job........


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
ABYC Certified Master Marine Electrician
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center*AMS Lithium Batteries
Lifeline AGM Batteries**Magnum Inverters***Victron Energy Components
541-490-6357

[Mcrid]

This thread is such a charge!!