Most Powerful Replacement Battery?

Getting close to the time for replacing my original battery. Price as no concern, any opinion as to the most powerful battery available that will fit in the battery box?

Thanks,

Randy

 

I suggest looking at this Deep Cycle Battery FAQ. Lots of good info on batteries, plus a great selection of possible replacements. Good luck and let us know what you find.

 

The original battery is a GNP Sprinter S12V300F rated at 65 amp hours.
GNB Sprinter S12V300F 12v 306w 68ah High Rate Sealed AGM UPS Backup Battery S12V300 S12V285 HX300-12 12HR300 FR PWHR12280W4FR

I kicked around the idea of 2 six Volt golf cart batteries for awhile but didn't want the extra weight and didn't want to give up the space.

After a lot of research, I went with the Vmaxtanks Mr107 rated at 85 amp hours for $24 more than the original. Added bonus is that it's 5 pounds lighter!
Amazon.com: Vmaxtanks MR107 12V 85AH Marine AGM SLA Deep Cycle Battery ideal for boats and 30lb-55lb thrust Minn Kota, Newport Vessels, Cobra, Sevylor and other trolling motors. BCI Group 24: Everything Else

Bought it direct from VMax with the thought that it might help ensure that I was getting the most recent model/production date. After their 10% off and free shipping it ended up being $5 less than Amazon.
MR107-85 Deep Cycle, High performance 85AH AGM Battery

I'll report back on the performance.

Randy

 

Randy am working to update battery/electical on trailer. Checking to see if you are happy with your vmax battery? Along with battery replacement adding a trimetic monitor and replacing the battery isolator with the CTEK charging station..let me know how the battery is working out..Thanks R

 

Hi Ron,

The new battery has been fine. I can't honestly say that I have noticed it lasting any longer (staying above 12) than the original battery even though on paper it has more amp hours (85 vs, 65). I would recommend buying direct from them to ensure you are getting new stock. It is lighter than the stock battery which is a plus.

I installed the old one in my truck to run the Dometic. Trying that out for the first time this weekend.

Best of luck with the trimetic install. Would be interested in install details at some future point. I would love to have one but a little intimidated by the installation.

Hope that all is well in the Quad Cities! I see the 74 bridge construction is in full swing. My Mom passed this past October and the rest of my family has moved to Des Moines so it's been awhile since I've been back there.

Best,

Randy

 

Sorry to hear about mom...prayers on their way....our ttwry can't seem to get above 13.2 so think it has developed a memory a d the on board charger does not help at this point hopefully the CTEK will help with that and TRIMETRIC will help monitor more closely. Cary/Craig and crew are going to handle the install, advantage of living close I guess. It may get cold here but we are 2 days drive.from everywhere in lower 48...

 

I seem to also have problems getting the battery fully charged at times, even the new one. I have noticed one thing. I keep the camper plugged into shore power when I am at home. It seems like when I unplug shore power and then plug it back in, the charging voltage jumps up to 14 plus. Don't know if that is a problem with or characteristic of the camper's charge controller.

 

Randy,

That is normal correct operation for that charger. When you first plug it in it will go into a high charge mode to measure the resistance in the battery to determine what mode it needs to switch to. That will be up to 14.8v potentially. Your charger has three stages so it will do a variety of voltages as it sees fit. Maintenance (storage) mode will be about 13.1-13.4v for that charger. The 13.2v Ron is seeing is correct for a battery that is fully charged and simply being maintained by the charger.

As I always recommend it is best for the owner to not concern themselves with what the voltage means because of this potential complexity. Two things you do want to concern yourself with however.

Is the charging working? This would be indicated by a rise in voltage on the volt meter, or with a newer model camper by an indication other than zero on the built in amp meter. Not seeing a rise in voltage would indicate either a lack of power going to the charger or a bad charger. Either way you would need to consult your charger troubleshooting flow chart in your owner's manual.

The other thing to concern yourself with is verifying the voltage does not rise above 15v which would indicate a failed charger due to being stressed by charging a failing or damaged battery. If you see voltage rising above 15v unplug and prepare to replace the charger.

Cary

 

Thank you Cary. Very helpful information.

 

On a related note . . .

Is there any simple way to test the original AGM battery? Have not had any problems, partly because we don't stress it much and most of the time have shore power. But it's 3.5 years old now and we have inadvertently discharged *way* down a couple of times to the point that lights are very dim or off. It *seems* OK and still holding a charge fine, but would like to know when to start thinking about replacement.

P.S. And when not on the road, it's always garaged and plugged in (except for those couple of times when it wasn't and somebody left a light or two on overnight).

 

Our 2007 Aluma-Inn (or should it be Illuma-Inn, can't decide) still has the original little 33 AH battery it came with, and the last time out in Oct. we didn't have shore power for a three day camp trip, but just used lights,TV, water pump, fantastic fan, and sound system, no Dometic that trip, just the cooler and block ice.
We always keep the teardrop plugged in whenever it's in storage so the battery tender charger it came with can do its job. So, to reply to Ghost Orchid, it still is keeping us powered with no outages after 11 years, but we have never run it down to dead either, so not sure how much that leads to an early demise. We are probably living on borrowed time with ours however, so listening to the rest of you for good replacement options as well.

P.S. Our 2004 Jeep Grand Cherokee with a little over 30,000 miles on it still has its original battery too, but I disconnect the neg. terminal, and always keep a Battery Tender Jr. on it as well between uses. Seems to work pretty well so far.

 

GhostOrchid,

Battery life is really based on amount of usage in cycles. A lightly used and well maintained AGM like Dustin's will easy make 10 years plus. The storage capacity decreases with the usage no matter the age. So, Dustin's is still working great but maybe it only has 70% of it's original capability (no idea the exact amount, just a WAG).

Of course a couple big discharges will reduce that capacity/years formula somewhat but if you are storing it properly with the maintainer then I would say you still have many years left if using it lightly the rest of the time as you describe. Now, if you are using it heavy whenever you do go out then that will affect the run time because there are more cycles on it. For example, if someone is regularly using a large DC load like a DC fridge or a CPAP machine and doing extended stays off grid, maybe with a solar panel on it that keeps charging the battery back up each day the amount of cycles on the battery will go way way way up. For someone doing this time of camping we see an AGM only lasting 3-5 years before the run time is just so short it becomes and issue.

To answer your original question though, to test the battery you would take it out of the camper and take it to an auto parts store or battery store to have it load tested. This will give you a rough idea where it is in it's life span.

Cary

Forums

 

when I suspected our original AGM (Dynasty) of being bad I took it to a Batteries Plus as well as an auto parts store. They both said the battery tested fine. The problem wasn't that it couldn't put out the voltage it was that the capacity was *way* down. Even in cool weather it wouldn't run the dometic over night with a full charge.
I had seriously diminished the capacity of the battery by too-often deeply discharging it and not getting it fully charged again. I am now the proud owner of a trimetric monitor and a Trojan AGM battery.
So be careful about trusting a test of your battery.

r dickson
550 #645

 

Robert,

That is a great point. Properly getting a feel for the condition of the battery capacity from a load test is a pretty subtle art. Just hooking up the load tester and making sure it goes into the "Good" range on the meter really is not helpful unless the battery is totally shot. I suspect this is what you ran into and others probably do to. It is doable but experience is key.

Cary