When the battery runs dead....

[EagleScout-USA]

Should the battery run down after a few days of dry camping, and the power awning and power slide are fully extended...will plugging into my running truck offer the necessary power supply to retract the awning and retract the slide? I may face this situation this weekend, and want to ensure I am prepared. Thank you.

[Ron3rd]

All good info above and a lesson I learned the hard way is if your batteries go dead, the only thing that will work is the stove.

[pianotuna]

Does this mean you have two twin banks?

RoyB wrote:
Additionally I will not start using my batteries again until they are at the 90% charge. This is approximately 12.5VDC

Roy Ken

[MEXICOWANDERER]

"I didn't realize the importance of NOT running the battery low. I actually thought that it was good to run it through a full discharge cycle"

Full cycling of NICKEL CADMIUM recharging protocol floated magically over to lead acid batteries. Assumptions can cost a lot of money. BTW, a good AGM battery will suffer less than even a golf car battery from over-discharge. Nevertheless, self-education is the only sure answer to prevent "innocent" mistakes. When I screw up, I blame myself for not taking the time to learn about the subject. "DEAD" is a relative term so attempts to guess exact degree of damage to the battery are shots in the dark.

[EagleScout-USA]

Thank you all for the advice and direction. I didn't realize the importance of NOT running the battery low. I actually thought that it was good to run it through a full discharge cycle, although I have never done so. I will not be investing in an increased number of batteries, or a high-end generator, as this type of camping will be few and far between; however, now realizing the potential negative impacts of dramatically decreasing the charge of the 12V battery, I will bring my 12-amp charger and 800W generator and let it run for a few hours to ensure I am trouble free. Most of our camping is and will continue to be with shore power.

[psuce]

wa8yxm wrote:
Unless you have expanded the battery bank the design is normally "overnight".

SO yes, days of camping it will run down.

Now: A true DEEP CYCLE (like a 6 volt golf car battery) May be ok if recharged swiftly.

MARINE/deep cycle.. Well you might get lucky but odds are poor

Starting batteries down that far are toast.

In my experience it depends on what exactly you're camping in and how conservative you are with power. My previous 22' TT with one 12v deep cycle battery I could "dry camp" for about 5 days before needing to recharge. With my new to me 32' fifth wheel with two 6V Trojans I went 9 days last year before needing to recharge. Granted this is with being conservative with power usage, using bath house for showers, and switching to led interior lights, but also included two set ups using landing gear and open/close one slide.

As other have said, check voltage daily or twice daily and recharge as necessary depending on your battery.

[MrWizard]

Scout moto "Be Prepared"
That means have enough battery
If you can't do that
Then recharge daily
Don't run them dead

[NinerBikes]

EagleScout-USA wrote:
Should the battery run down after a few days of dry camping, and the power awning and power slide are fully extended...will plugging into my running truck offer the necessary power supply to retract the awning and retract the slide? I may face this situation this weekend, and want to ensure I am prepared. Thank you.

Yes, if you let the alternator charge for probably a half an hour or more, with jumper cables.

As to the unasked question... These are not like flashlight batteries, you don't run them lower than 50 to 60% state of charge remaining. Lower than that shortens their life dramatically. Recharge them daily.

Will it probably destroy the battery running it all the way down from 3 days of camping? Yes, it will most likely do so. It will dramatically shorten the life of the battery, if not altogether kill it.

[wa8yxm]

Unless you have expanded the battery bank the design is normally "overnight".

SO yes, days of camping it will run down.

Now: A true DEEP CYCLE (like a 6 volt golf car battery) May be ok if recharged swiftly.

MARINE/deep cycle.. Well you might get lucky but odds are poor

Starting batteries down that far are toast.

[3oaks]

Well, at least 3 replies answered the original questions. Like with many topics, much advice is given without answering the original poster's question, the real reason for the post. :R

By the way, I was also interested in the answer to the original question and not how to prevent the problem in the future. I already knew that. However, things do not always go as planned. :@

[RoyB]

I do not ever let my Batteries get below 12.0VDC...

This is the approximately 50% charge state and continuing going lower will eventually do harm to your batteries. For us this is the time to stop using the batteries and start re-charging.

Additionally I will not start using my batteries again until they are at the 90% charge. This is approximately 12.5VDC

Charging from the 12.0VDC state to the 90% charge state will take around 3 hours of charging using smart mode charging with the DC Current capacity of 17-20AMPS of DC Current for each battery being charged in the battery bank.

Whenever we would just charge for an hour (quick charge) or so the batteries would start losing their performance and drop to the 12.0VDC state quicker each time. Continuing to do this will eventually do unrepairable harm to your batteries.

The trick for us is to never get into this situation of not having enough battery to do what you want to do...

My four 12V deep cycle batteries were purchased in 2008 and I lost one right away for not charging them properly using a constant 13.6VDC type charger. The other three batteries have done me great up until last year 2015 where one them just would not hold a charge above 12.2VDC for any length of time. This season another 12V battery did not survive my charging to full 100% mode and removing the battery terminals over the winter months. I am down to only one good performance 12V Deep cycle battery at this point and the last battery starting to only hold a charge up to the 12.2VDC level. I'd say not bad for 8 years with an initial cost of $75 for each of the four 12V 85AH Deep Cycle INTERSTATE GP24 batteries.

I am planning on replacing these with two groups of 6VDC Golf Cart batteries in series giving me around 450AHs of capacity for about $450 or four each of the Trojan 12VDC 150AHs T-1275 giving me 600AHs capacity which will cost around $500-$600 if I am lucky... If I can get these to last 8 years than even the $600 would be a good deal... Going with the Trojan batteries will also require me to change out my on-board converter/charger unit for one that produces 14.8VDC Boost charge voltages. That will be another expense to deal with if I want to be able to get from the 50% charge state to the 90% charge in a quick three hour charge time when camping OFF-GRID...

Roy Ken

[Strabo]

Yes, allow the truck a few minutes to charge the battery some then you can do what you asked. If you have a large Alternator on your truck you can hook up the trailer battery with jumper cables, this will help charge your battery much faster.

Run the trucks rpm above idle. My HP Alternator in our truck will put a large amount of charge back into the battery bank in a short time.

[NinerBikes]

Recharge the batteries for the awning daily, before they get low, in charge, let alone go dead, usually first thing in the morning.

[pickjare]

Running the batteries that low will reduce their life so they will reach this point sooner and sooner on future trips. If you know that you are that short on battery capacity install better batteries, more batteries, solar, or generator now so you can have the best experience in the future.

[RJsfishin]

If all is connected and working as its supposed to, yes.
But jumpering TV battery to trailer battery, will work faster.