Coach batteries toasted?

[oyly]

Can't run the cabin heater through the night without draining the batteries down. Seems very strange that it would need so much power. Should only be the electric fan that needs the electric power?

Anybody have similar experiences?

[oyly]

Canadian Rainbirds wrote:

oyly wrote:
So I found out my batteries are NAPA 8240. 24DCM:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Battery-Deep-Cycle-12-Wet/_/R-NBD8240_02137...

Seems you were right 2112, they're not real deep-cycle batteries. The label says "Marine/RV Dual Purpose". NAPA also doesn't state the Ah rating, which I've learned, is typical for non-deep-cycle batteries. But to estimate the Ah rating, some say divide the reserve capacity by 2. That gives me an Ah of just 70.

Been looking for a user manual for these batteries, but can't find any. The one in my Winnebago manual also doesn't say anything about checking the SG. So I'm not sure if I'm able to! There seems to be two lids on top of the batteries, but prying them off was harder than what seems normal, so I'm worried I'll break something if I try harder...



Also started looking into bigger batteries. I would have to make some modifications to the tray where the batteries sit, as this was clearly made for exactly group 24 batteries. As for a more powerful battery in the same size; Seems they all have about the same amount of power, 140 A reserve capacity.

Did anyone reading this increase the battery capacity in their RV? How did you do it?

It's hard to see for sure by the photo, but do you perhaps have a couple more inches in available height? If so you could go to a couple of 6V Colf Cart batteries. Same foot print but a bit taller. That would give you anywhere from 220 AH to 240 AH depending on which battery you get.

In our previous motorhome I had a welding shop remake the battery shelf a bit lower in order to do this. It adds a bit of weight since GCs weigh 66 pounds each on average.

I have maybe half an inch available in height, before I have to start moving the bracket on top. If I move this, I could fit a couple more inches in height, but would have to move the fuse.

If I do like you and have a welding shop remake or build from scratch a new shelf, I could fit batteries that are both quite a bit taller and longer.

[mpierce]

Canadian Rainbirds wrote:

oyly wrote:
So I found out my batteries are NAPA 8240. 24DCM:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Battery-Deep-Cycle-12-Wet/_/R-NBD8240_02137...

Seems you were right 2112, they're not real deep-cycle batteries. The label says "Marine/RV Dual Purpose". NAPA also doesn't state the Ah rating, which I've learned, is typical for non-deep-cycle batteries. But to estimate the Ah rating, some say divide the reserve capacity by 2. That gives me an Ah of just 70.

Been looking for a user manual for these batteries, but can't find any. The one in my Winnebago manual also doesn't say anything about checking the SG. So I'm not sure if I'm able to! There seems to be two lids on top of the batteries, but prying them off was harder than what seems normal, so I'm worried I'll break something if I try harder...



Also started looking into bigger batteries. I would have to make some modifications to the tray where the batteries sit, as this was clearly made for exactly group 24 batteries. As for a more powerful battery in the same size; Seems they all have about the same amount of power, 140 A reserve capacity.

Did anyone reading this increase the battery capacity in their RV? How did you do it?

It's hard to see for sure by the photo, but do you perhaps have a couple more inches in available height? If so you could go to a couple of 6V Colf Cart batteries. Same foot print but a bit taller. That would give you anywhere from 220 AH to 240 AH depending on which battery you get.

In our previous motorhome I had a welding shop remake the battery shelf a bit lower in order to do this. It adds a bit of weight since GCs weigh 66 pounds each on average.

This is what I would, and have, done. Get the foot print size of the batteries you have. Go look up the TALLEST 6 volt, true deep cycle batteries that fit in that footprint. Hook them up to make ONE 12 volt battery. That will give you the most electrical power you can get in the existing space. If you want MORE power storage after that, you will need to find a way to add more batteries.

Also, make sure you have turned OFF or minimized as much power draw as you can. LED lights, etc. Makes a HUGE difference in battery life.

Try to NEVER draw the batteries below 50% of their rating. Shortens battery life, and they are expensive. If you draw them down to where you notice by lights and such that they are low, you are waaaay below 50%. $$$$$ out the window!

[2112]

If you want to see if you can save these pull them out, clean them up, remove the caps (they will come off, just pry them up evenly) check/add distilled water and give them a good charge with a good charger. Check the SG and continue charging if low. You will most likely find one or two cells lower than the others.

You may need to acquire a charger that will perform a condition/equalizing charge.
A cheap DMM is always good to have a well.

[2112]

Something like a Trojan T-105. They are 11.07" (281mm) tall.
Your NAPA 8240's are 9.375" tall. Can you go 2" taller?

The NAPA 8302 will give you slightly more performance with the same size compared to your 8240.

[Canadian_Rainbi]

oyly wrote:
So I found out my batteries are NAPA 8240. 24DCM:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Battery-Deep-Cycle-12-Wet/_/R-NBD8240_02137...

Seems you were right 2112, they're not real deep-cycle batteries. The label says "Marine/RV Dual Purpose". NAPA also doesn't state the Ah rating, which I've learned, is typical for non-deep-cycle batteries. But to estimate the Ah rating, some say divide the reserve capacity by 2. That gives me an Ah of just 70.

Been looking for a user manual for these batteries, but can't find any. The one in my Winnebago manual also doesn't say anything about checking the SG. So I'm not sure if I'm able to! There seems to be two lids on top of the batteries, but prying them off was harder than what seems normal, so I'm worried I'll break something if I try harder...



Also started looking into bigger batteries. I would have to make some modifications to the tray where the batteries sit, as this was clearly made for exactly group 24 batteries. As for a more powerful battery in the same size; Seems they all have about the same amount of power, 140 A reserve capacity.

Did anyone reading this increase the battery capacity in their RV? How did you do it?

It's hard to see for sure by the photo, but do you perhaps have a couple more inches in available height? If so you could go to a couple of 6V Colf Cart batteries. Same foot print but a bit taller. That would give you anywhere from 220 AH to 240 AH depending on which battery you get.

In our previous motorhome I had a welding shop remake the battery shelf a bit lower in order to do this. It adds a bit of weight since GCs weigh 66 pounds each on average.

[jsikora]

A furnace suck alot of power. Most RV manufacturers dont plan people to run the furnace at night. Our 5th wheel came with a single 12 volt battery. It wouldn't pass 2 hours of furnace when dry camping. I upgraded to a second 12 volt, but also installed 4 - 300 ah batteries in the front compartment for my inverter. I installed a battery switch and could switch to these.

[oyly]

So I found out my batteries are NAPA 8240. 24DCM:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Battery-Deep-Cycle-12-Wet/_/R-NBD8240_02137...

Seems you were right 2112, they're not real deep-cycle batteries. The label says "Marine/RV Dual Purpose". NAPA also doesn't state the Ah rating, which I've learned, is typical for non-deep-cycle batteries. But to estimate the Ah rating, some say divide the reserve capacity by 2. That gives me an Ah of just 70.

Been looking for a user manual for these batteries, but can't find any. The one in my Winnebago manual also doesn't say anything about checking the SG. So I'm not sure if I'm able to! There seems to be two lids on top of the batteries, but prying them off was harder than what seems normal, so I'm worried I'll break something if I try harder...



Also started looking into bigger batteries. I would have to make some modifications to the tray where the batteries sit, as this was clearly made for exactly group 24 batteries. As for a more powerful battery in the same size; Seems they all have about the same amount of power, 140 A reserve capacity.

Did anyone reading this increase the battery capacity in their RV? How did you do it?

[jerseyjim]

2112: Interesting question. My gasser motorhome, bought new in 2001, gets around 3 years out of any conventional battery (6V or 12V) most any brand....from Interstate to Sams' Club. (BTW, now using DEKA)

Doesn't seem to matter.

[2112]

My thoughts:
I do not believe they make group 24 'deep cycle' batteries. I'm sure you have marine 'hybrid' batteries.

From your comments I'll suspect you have neglected your batteries. If so, they will never return to maximum, like new capacity no matter what you do. I seriously doubt they can still provide close to 80Ah/charge.

Now that you better understand the importance of proper battery maintenance it may be prudent of you to start over with new batteries and see if you can protect them better. A pair of group 27's would be better than the 24's but you may need more. Do a power audit to determine your real world needs. Do you have room for bigger batteries? I don't. Can you properly maintain and charge a bigger pair?

Not knowing your camping style this could be delayed to a later date. Do you foresee relying on them to supply maximum potential in the near future?

FWIW: I neglected my first battery when I was learning. I never paid any attention to it until it started to fail after about two years of use. Now I equalize them every three months, top off with water when needed and they can last for at least 6 years or longer. The question is do you want to put in the effort to maintain them for longevity or just replace them every few years as needed?

[jerseyjim]

Only once....dry camping in a Wal-mart parking lot on a 20 degree nite did i go this route. (Without the generator) After 7 hours...the fan still worked..but seemed weak(er) than earlier in the evening. No matter...the V-10 started just fine and that began the re-charging of the 2 6V coach batteries.
I might have "gotten-outta-there" just in time. But..for 7 hours, it worked.

[oyly]

OK, so I've found out that I have two group 24 deep cycle batteries. 12V and 80Ah each. If like scrubjaysnest writes, I can only use 50% of that capacity, then 80 Ah / 10 A (worst case?) = 8 hours of running time for the fan.

So even in perfect condition, the batteries would just barely last the whole night. I'm surprised, seems like the system is under dimensioned. Will definitely check the SG and possibly install some extra batteries as well.

[donfrump]

oyly wrote:
Can't run the cabin heater through the night without draining the batteries down. Seems very strange that it would need so much power. Should only be the electric fan that needs the electric power?

Anybody have similar experiences?

to answer your question assuming you 1)have sufficient battery power and 2)you know there top notch shape and 3)were previous to this charged fully then the RV lpg furnace should not deplete the batterys over the course of a nite (10) hours

[Triker33]

So has the water level been checked in them since RV was bought. Probably not since number of batteries seem to be unknown. 😞

[Canadian_Rainbi]

oyly wrote:


It's a 2014 Winnebago Via. Think it has two batteries, and these have been well drained a few times.

This says a lot. A recipe for battery failure.

If you are not sure how many and what type and size of batteries you have then it is pretty obvious that you have not been checking them regularly and have likely suffered at least somewhat from under or over charging. "well down" makes me assume you mean more than 50% (12.2 volts). True deep cycle batteries can take some very deep discharges with some loss of life.

Find out what batteries you have, what shape they are in now (SG etc) and what charger or converter you have.

Learn as much as a you can about the care and feeding of lead acid batteries.

Then you should get many years out of you batteries.

Don't feel bad about not having treated you batteries well, I would suspect that many if not most on this forum have done the same in the past and/or are still doing so.

I killed 4 group 24s by a season of chronic undercharging then almost killed the replacement 4 6V GCs when the power went off for an unknown period of time with both roof fans running. They seem to have recovered relatively well, only time will tell.