Batteries for 5th Wheel

[Casey Balvert]

I agree with the previous posting. Voltage will only tell you the state of charge if you let it rest about 20 yours and who does that? The voltage will NOT tell you what the battery can deliver.



I use a Cruising Equipment E-Meter on my fiver. It monitors the number of amphours removed from the battery as well as volts and amps using very comples algorhythms. It calculates the amount of time remaining in the battery as well.



You must remember that you cannot get every last amp out of a battery. The voltage drops too low and stuff will not run right. At best with normal loads using 75% of the capacity of the battery is the best compromise one can hope for unless your loads are very very light.



Another thing to remember is that most battery manufacturers lie about capacity, at least in real world terms. I have four 6 volt batteries wired into a bank to provide twelve volts. The advertised capacity is 450 amp hours using the 20 hour test. When I tested my current batteries after putting five cycles on them their real capacity was 360 amp hours and this sort difference between what they advertise and what they actually produce is typical. I did have some gel cells that produced what they advertised after five years but they are very expensive.



Also if you want your batteries to last a long time you should not let them go below 50% of their capacity. Deep cylcing even Deep Cycle batteries will shorten their life significantly.



westmarine.com has some interesting reading in their West Advisor section on batteries. Take the time to educate yourself.



Cheers, Casey

 

[TowPro]

this is true with most older type chargers, but some of the new RV's are comming with chargers that work much better.



My 2000 Terry came with one from Progressive Dynamics I bought the "charge Wizard" and have had no problems in 3 years, with it plugged in all the time. I think most new Fleetwoods come with this charger. The "charge wizard" that plugs into this charger was a good investment.

Originally posted by DHawthorne

If you have a inverter and let it run while hooked up to the shore tie at the camp site, the battery will over charge and shorten life

dramatically. Don't know if you have a inverter or not. I installed

a knife switch in the battery space and when I'm plugged in, I turn the back feed from the inverter to the battery off. I also turn it off after its back at the house to keep that LP gas alarm from draining the Battery while the rig is parked. I cooked one battery already last year.



Dave

 

[ronco]

Originally posted by JWhitcomb

Ronco,

I have seen the testers you are talking about but never had to opportunity to get my hands on one. They seem to have some sort of dummy load which is covered by a heat shield and a analog meter. I have been under the impression that they are for testing cranking batteries but often wondered if they work well for deep cycles. Do you use one for deep cycles?

IMHO, I would use this tester for both type batteries. Marine batteries have a cranking value listed on the side, and can be tested the same way. Without loading a battery, it's condition is unknown.



Ronco

 

[GeneralMachine]

Load Tester (Battery)

I have one that SnapOn Make's, It has the gridd in it that put's a load on the batt. I have seen battery's show 12v and when the trigger is pulled the meter just fall's to zero, weak battery's with a problem fall slower but still drop to nothing pretty fast, testing a good one you can hold it and the gridd will turn red but the volt's hold above 12. Harv

 

[Casey Ray]

Battery box for 6 volt batteries

Here is a cheap and easy solution to the 6v battery box height problem. Find a suitable battery box that your battery will fit in, then buy four of them. Separate the boxes into two stacks of two. Take one of the battery boxes that is sitting in the other and cut the bottom out of it then replace it in the bottom 2nd battery box, do that for both sets of battery boxes. Now you can rivet the boxes together or bolt them together, silicone them together which is what I've done. I've been thinking of using some plastic contact cement like for pipe, would melt them together. Best part is, the original battery box lid fits and it is way cheaper than the commerical made boxes upwards of $80.

Hope I explained it enough.



HTH,



Bocifus

Originally posted by JWhitcomb

No tips from me that will help. I am just like you, three years for a Costco deep cycle is a full life. I run my newest battery as my main one for starting and keep two others that are older in the rotation as units for the trolling motor. I try to keep my best battery no more than one year old. I am thinking of mounting two golf cart batteries in the wheel wells of the truck bed to extend the slide-in total amps in winter. Trouble is no one makes a box for those big batteries that I can find.

 

[MrFixit]

Batteries

I have had good luck with the Trojan 105's. I really like them and charge them w/ 3 stage charging. Here are some voltage and % capacities that I use found at Mark's RV Adventure

http://www.ccis.com/home/mnemeth/12volt/12volta.htm



Voltage State of Charge

12. 6+ --- 100%

12. 5 --- 90%

12. 42 --- 80%

12. 32 --- 70%

12. 20 --- 60%

12. 06 --- 50%

11. 9 --- 40%

11. 75 --- 30%

11. 58 --- 20%

11. 31 --- 10%

10. 5 --- 0%





JWhitcomb... as for battery box, this is a real nice one for the 6 volts





http://www.westmarine.com/webapp/wc...=10001&classNum=208&subdeptNum=207&storeNum=9



or at Westmarine.com under "All battery accessories. My friend has the box mounted on his trailer tongue (it is TT though)



Wayne's Electric in Long Beach CA sells them for around $60

 

[MCrossley]

Another thing to remember is that most battery manufacturers lie about capacity, at least in real world terms. I have four 6 volt batteries wired into a bank to provide twelve volts. The advertised capacity is 450 amp hours using the 20 hour test. When I tested my current batteries after putting five cycles on them their real capacity was 360 amp hours and this sort difference between what they advertise and what they actually produce is typical. I did have some gel cells that produced what they advertised after five years but they are very expensive.

Remeber you do not gain amp/hour capacity by going in series just parralell. You may have considered that but thought I would say something for those who do not know... If you have 2 100Amp/hr battereis and put them in series for 24 volts you will still only have 100Amp/hr capacity just something I thought I would throw out. The Trojan t-105's and l-16's are very good for these applications they are real hard to hurt and provide good extended draw capcaity.



Here is a link to the pics of my inverters, chargers and batteries in both my truck and trailer... Truck and Trailer pics

 

[Casey Balvert]

Originally posted by MCrossley

Remeber you do not gain amp/hour capacity by going in series just parralell. You may have considered that but thought I would say something for those who do not know... If you have 2 100Amp/hr battereis and put them in series for 24 volts you will still only have 100Amp/hr capacity just something I thought I would throw out. The Trojan t-105's and l-16's are very good for these applications they are real hard to hurt and provide good extended draw capcaity. ... ... ... ... ... ... ... ... ...

I based my capacity figures on two Golf Cart six volts in series wired in parallel with another pair. A total of four batteries. Each six volt battery is rated by the manufacturer at 225 amp hours so the combination was rated at 450 amp hours. Actual testing indicated a total amp hours of 360 for this set up. And real world use would be considerably less because voltage drops as you deplete the batteries and while the capacity test ends at 10. 6 volts most stuff won't run at that voltage. Once it drops much below 11. 9 or so with a four of five amp load you need to recharch. In fact it is best for battery life to recharge once you have used 60 percent or so of the actual battery capacity.



The only batteries that I have used that actually put out the rated capacity were gel cells.



Casey

 

[klenger]

I try not to run my batteries below about 50 - 60 %. I understand they will last longer if you don't discharge them as much.