Battery Replacement/Upgrade Question

[Poppy's 5th Wheel]

I currently run 2 - 12 volt deep cycle batteries. They have done a fine job and are now about 3 1/2 YO and no longer holding a charge long enough without being charged. I'm trying to decide if I want to just replace them, certainly the cheapest option, or switch to 6 volt batteries. We primarily camp with hookups but I like the ability to choose some locations where electricity is not available and also want to add an invertor to the rig. I might even consider 4 - 6 volt or 4 - 12 volt just to increase the overall capacity.

My real question for today is regarding my convertor. Will my OEM convertor have any restrictions recharging my batteries no matter which configuration I decide on? Should it be any part of my decision process?

In case it matters, the rig is 30 AMP.

Thanks for your help.

[Festus2]

You will get the highest capacity/amp hours from 6 volts. We have 2 Trojans and I would recommend these "work horses". The converter doesn't care whether you have 6 or 12 volts as long as they are wired properly so it doesn't matter about the configuration. As you know, two 6 volts need to be wired in series. And no, it doesn't really matter whether your RV is 30 or 50 amp - the batteries will still get a sufficient charge from the converter.

I'd go with 6 volts and Trojan would be my choice. If you just spend the odd time dry camping and not without hookups for long, extended periods of time, 2 - 6 volts should suffice. Having 4-6 volts would be ideal but think about the extra weight and cost involved and whether or not these two factors warrant going with 4.

[Poppy's 5th Wheel]

Thanks Festus. I have been looking at the Trojans but there seems to be so many different models which have me a bit confused. T 105 vs T 605. I can get T 105s locally for $125 which looks like a good price for a high performance battery at 225 amp hours.

[Festus2]

Originally Posted by Poppy's 5th Wheel

Thanks Festus. I have been looking at the Trojans but there seems to be so many different models which have me a bit confused. T 105 vs T 605. I can get T 105s locally for $125 which looks like a good price for a high performance battery at 225 amp hours.

There isn't a lot of difference between the two but the T105's have a bit better capacity/amp hr rating. They are also a little more expensive and heavier - but not by much.

At $125 for a T105, I would think that would be a pretty decent price!

When our T105's decide to quite, I'll be replacing them with the same ones. We've had 6-7 years service from them --- still performing well.

[Poppy's 5th Wheel]

Great. I think that's the direction I will go. I hope to bug you with another question and see if you can help.

I plan to add an invertor just to run the TV and laptop. I had intended to mount the invertor in the battery compartment and then run wiring into the trailer where the TV mounts. Is that preferred rather than to mount the invertor where the TV is and run the wiring up to the battery compartment?

I just didn't know if it made any difference.

I also had read that I want an invertor that is close to what I want to run, in other words, I don't need a 4000W invertor to run a single TV and a laptop. Maybe 1000W or even less?

[Festus2]

I would mount the inverter and battery as closely together as possible. If you have a long run from the battery to the inverter, you could see a significant drop by the time it reaches the converter - especially with smaller gauge wire. The shorter the run, the better. So I'd mount the inverter near the battery and then run your 110v power line from there to the TV.

You are right in that there is no sense in having a 4000w inverter if all you are going to run is the TV and a laptop. A 1000w will be more than adequate for these two items.
Remember that the inverter draws from your batteries. If you have a 4000w inverter, the tendency might be to utilize those watts and start operating curling irons, toasters, etc. The larger the inverter and the more "stuff" you plug into it, the more drain you'll have on your batteries.

[hankpage]

I have a 1000w inverter and it works well for a tv or my air compressor if I need it. If I had to get another I would get a 2000w with a remote switch. It would be nice to make a pot of coffee in a rest area and a 2000w would give me that little extra and with the remote I would not have to go outside and open the storage compartment to turn it on and off. Even when no appliance is being used there is a considerable draw on the battery while the inverter is on. JM2¢, Hank

[Poppy's 5th Wheel]

Originally Posted by hankpage

I have a 1000w inverter and it works well for a tv or my air compressor if I need it. If I had to get another I would get a 2000w with a remote switch. It would be nice to make a pot of coffee in a rest area and a 2000w would give me that little extra and with the remote I would not have to go outside and open the storage compartment to turn it on and off. Even when no appliance is being used there is a considerable draw on the battery while the inverter is on. JM2¢, Hank

So may I ask how you have your current inverter setup? Any pictures? I was thinking I might run wiring into the LR and mount a outlet next to the shore line outlet (marking it as inverter power) and then just plug the TV into it when not on shore power.

I've read of some very complex installations where larger invertors are used and everything always run through the invertor whether you're connected to shore power or running off the batteries but that seems way to complex for my simple needs and I would require someone else to install that system.

[Poppy's 5th Wheel]

Well, I just ordered 2 - 6 volt Trojan T105 225 amp batteries and a Sunforce 1000 Watt Pure Sine Wave Inverter with Remote Control. Inverter here by Wednesday and the batteries are being delivered Saturday. Hopefully it will be a fairly straight forward installation.

We're headed out in 2 weeks for 4 nights on the beach with no hookups so I was in a little hurry to get this done. I imagine if I don't have time to do a professional install of the power into the LV I could just run an extension cord temporarily from the front compartment into the trailer but I think with a full weekend available I should be able to get it all set up correctly.

Thanks for your input and any other insight would continue to be appreciated.

[Festus2]

Paul -
I'm sure you'll be pleased with the Trojans and how they perform. If, as you say, your needs are fairly simple with respect to the inverter and what you plan on using it for, the K.I.S.S. principle always makes good sense. It seems that you don't require anything too complex so why make it more difficult than need be?
Good luck with your install. Did you manage to get a battery box for the 2 Trojans? They are heavy brutes so take care when lifting and installing them.

[Poppy's 5th Wheel]

Originally Posted by Festus2

Paul -
I'm sure you'll be pleased with the Trojans and how they perform. If, as you say, your needs are fairly simple with respect to the inverter and what you plan on using it for, the K.I.S.S. principle always makes good sense. It seems that you don't require anything too complex so why make it more difficult than need be?
Good luck with your install. Did you manage to get a battery box for the 2 Trojans? They are heavy brutes so take care when lifting and installing them.

I have a source for the battery boxes but the place I bought the Trojans from tells me they should fit in the bases of the existing 12 volt boxes but that the tops are tall enough so I'm going to check fitment out first to see if I can modify the box tops. If not I will order some new boxes. The ones I did find don't have the connection on top for the vent tube so I may need to do some more research.

[trucker LOU]

Hey Poppy, when I made the switch the boxes had no vent. used pvc elbows, into top of box to attach to existing vent line. This was 4/6s in two boxes but would work for 2/6s & 1 box .---Lou---

[Poppy's 5th Wheel]

Originally Posted by trucker LOU

Hey Poppy, when I made the switch the boxes had no vent. used pvc elbows, into top of box to attach to existing vent line. This was 4/6s in two boxes but would work for 2/6s & 1 box .---Lou---

Clean setup Lou! Thanks for the pics.

[PSITracy]

Originally Posted by Festus2

You will get the highest capacity/amp hours from 6 volts. We have 2 Trojans and I would recommend these "work horses". The converter doesn't care whether you have 6 or 12 volts as long as they are wired properly so it doesn't matter about the configuration. As you know, two 6 volts need to be wired in series. And no, it doesn't really matter whether your RV is 30 or 50 amp - the batteries will still get a sufficient charge from the converter.

I'd go with 6 volts and Trojan would be my choice. If you just spend the odd time dry camping and not without hookups for long, extended periods of time, 2 - 6 volts should suffice. Having 4-6 volts would be ideal but think about the extra weight and cost involved and whether or not these two factors warrant going with 4.

Just went from 2 12V to to 2 6V Interstate, If Im understanding you correctly the onboard charger or generator wont need to have any adjustment ? If so I only have one forther question , if I want to hook up a battery charger, do I charge them individually at 6V or together at 12V ?

[JRTJH]

Originally Posted by PSITracy

Just went from 2 12V to to 2 6V Interstate, If Im understanding you correctly the onboard charger or generator wont need to have any adjustment ? If so I only have one forther question , if I want to hook up a battery charger, do I charge them individually at 6V or together at 12V ?

You can charge them individually at 6 volts or in series at 12 volts, that's your choice, but understand that you must completely disconnect the batteries from each other to charge at 6 volts. As long as they are connected together in series, you can't charge one singularly.

Also, realize that if you are trying to use the converter to charge them, if you connect any battery charger to the batteries, the converter will sense the extra voltage and shut itself off "thinking the batteries are charged" because of the "other charger voltage being applied to the circuit.

I believe that most people who use two (or more) 6 volt batteries to power their RV consider the entire assembly as "one big 12 volt battery" and use 12 volts to do most everything. It's a hassle to disconnect batteries and treat them as a 6 volt unit, then reconnect them to power the RV.

[Festus2]

Originally Posted by PSITracy

Just went from 2 12V to to 2 6V Interstate, If Im understanding you correctly the onboard charger or generator wont need to have any adjustment ? If so I only have one forther question , if I want to hook up a battery charger, do I charge them individually at 6V or together at 12V ?

PSITracy:
You do not need to make any adjustment to your converter (on board charger) or a generator if you use this in lieu of shore power. As JRTJH mentioned, just think of the 2-6volts as 1-12 volt and if you plan on using a separate battery charger, charge them up as one unit. Just make sure you put the charging leads on the correct battery terminals --- the + on one of the 6v and the - on the other 6 volt.

[Poppy's 5th Wheel]

Originally Posted by Festus2

PSITracy:
You do not need to make any adjustment to your converter (on board charger) or a generator if you use this in lieu of shore power. As JRTJH mentioned, just think of the 2-6volts as 1-12 volt and if you plan on using a separate battery charger, charge them up as one unit. Just make sure you put the charging leads on the correct battery terminals --- the + on one of the 6v and the - on the other 6 volt.

I guess my question would be if using another charger, other than the on board charger, would be of any benefit? Would it charge better or faster? If so, what would I look for specifically in a charger?

[Festus2]

Your best bet is to use the onboard converter's charging system to charge the batteries. It will do the job much better and faster than a separate one. Next, in term's of effectiveness would be to use an external, separate battery charger, hook it up to a generator and do the charging that way.

You can't use both the converter and a separate battery charger at the same time. Once the converter senses that the batteries are being charged by some other source, it won't function as a charger.

If you have a generator, it probably has a 12v DC charging outlet on it - most do. You can expect around 7-8 amps output (DC) from the generator. Not sure if you have one or not and if you do, what wattage it is.

Actually, I don't see much point in packing around a separate battery charger - especially if you are plugged in to shore power most or all the time. The converter, when you are plugged in, handles the battery charging very well.

[PSITracy]

Thank you very much for all of the replies, I learned quite a bit in this thread. I should have been more clear about my question. I was referring to Maintenance charging in offseason/non-use situations. Im really hoping to keep these new batteries around for a spell

[Poppy's 5th Wheel]

Originally Posted by Festus2

Actually, I don't see much point in packing around a separate battery charger - especially if you are plugged in to shore power most or all the time. The converter, when you are plugged in, handles the battery charging very well.

Thanks Festus2. I am only talking about recharging when boondocking. I agree they will charge fine when connected to shore power through the converter. I guess what I wasn't sure about was if the convertor is as efficient when the trailer is connected to my Honda 2000?

I also have the mate so I can use both Honda 2000s but I usually only do that when I need to run the air or microwave.