Extra Batteries

[Shadrach]

I have a TT with 2 Interstate U2200 ( GC2 ) 6V golf cart batteries mounted on the tongue. I also have an 80 watt solar panel and a 1750 inverter. I want to add more. I usually camp in treed areas for shade and privacy. Another solar panel or 2 would be nice but not in the current budget, so I thought I would add more batteries. The 6V are only 2 years old so there is still years left in them. There is no more room on the tongue without major mods and that would add extra weight, although that would probably help with the ride. So I thought about adding another battery or 2 in the back of the truck box. I could use a cable set up like fork lifts do to join the two sets of batteries.



My choices are 2 ( or 4 ) more 6 volts like what I have already, 2 group 29 12v or 1 or 2 group 4D 12v all deep cycle of course. I would probably mount them between the tailgate and rear wheel wells, that I'm not worried about. For charging purposes I would run an isolator and heavy wire so that when I go on a day trip the truck would charge them up.



Question: Would having the "truck" batteries and the "tongue" batteries at different levels of charge cause me problems?



I've had good success with the 6 volts ( the first pair lasted me 7 years ) and am aware that if 1 dies the pair is dead and both need replaced. If I have 2 12s and 1 dies I still 1 left. Do I need to replace them both? I don't believe so.



I have tried generators in the past but prefer the peace and quiet of battery power. Hmmm what if I just put a fork lift battery in the back of my truck, them I would have lots of reserve :-laf not to mention weight.



Some of you have lots more real life experience that I do. Your comments and thoughts please. Shadrach

 

[Skydiver]

I do know from experience that if batteries are not allowed to drop below 12. 3 volts they will last far longer. I have a Mercedes diesel battery in my Ford Tractor that I crank and use about 12 times a year. That battery has lasted 8 years. I place it on a battery maintainer every 2 months. Tractor gets used in spring and fall.
It's almost a trade off. If you use two batteries that last 2 years or 6 batteries that last 6 years the overall cost is the same. I prefer more batteries because of the reserve capacity and the fact that I'm not as likely to drop the voltage below 12. 3. I have read about folks that use 6 batteries and with proper care get get 10 years use.
Have you read this? Batteries -- and Other Electric Stuff by phred

 

[HBarlow]

Batteries, like living things, deteriorate with age so your two year old batteries are not what they were when new. I don't know how much or at what rate they decline. If you add two fresh new batteries in parallel with the two year old pair the new batteries will be limited to the capablility of the older pair. The same is true with all batteries including the 12 volt pairs in our Rams.

A voltage drop will result from long cable runs between batteries and loads, don't know how much actual effect.

Installing a heavy pair of 6 volt batteries behind the axles in a relatively light travel trailer will cause balance, weight shift, and towing issues. Probably not a great idea.

 

[Road Dog]

The truck won't charge extra batteries in any meaningful way. The charging system is designed to trickle charge the main batteries and will stop charging when the ECM thinks they're full. A better approach is to use an inverter and a smart charger for the batteries.

How much power do you need anyway? If I'm not running the furnace (and it's blower) I can easily get a week out of a single 12V 85AHr battery. Harvey's right about mixing old and new batteries. If you're determined to add capacity then add isolators so you can use the TT batteries OR the truck bed batteries but not both together.

 

[Shadrach]

Thanks guys. Good article Skydiver. How much power do I need/want? Well the trailer is an 87 Prowler 24', no A/C or TV/Computer, but we did add a microwave and a toaster oven that gets used briefly for some meals. ( Happy Wife - Happy Life ) The lights are all bulb style and I added a Fantastic Fan. It probably gets used the most other than lights and I don't turn on any more than necessary. If it's real warm the fan can go all evening to cool it down before bed time. I try to be conservative on all items, water for example and therefore the water pump. We use the campground washrooms if possible, the exercise is good. Dishes do get done in the trailer.



Dry camping, even in a Provincial campground, gives us much more choice of where to stay and we have adjusted our ways of doing things. For example no coffee pot, we use a kettle on the stove for our tea and use the oven and burners for most meals. I also take along a portable BBQ. It can get cool camping in the mountains and valleys even in August so the furnace does get used from time to time, usually just to take the chill off first thing in the morning unless it's been real cool at night. We have extra blankets and sleeping bags. A cup of tea and a sweater warms you up in the morning. I don't want to be too hard on the family, after all we are spending 24/7 together.



Shadrach

 

[Road Dog]

But how long are you "roughing it". In the past we had a small Honda inverter generator (and smart chargers) to charge the batteries. Very quiet. Coleman makes a gas cooktop drip coffee maker that work great. That just leaves the toaster as the big power hog. (I only use the microwave when I have shore power. )

 

[Shadrach]

We are OK for the weekend but when we go for a week we can run out of power especially if it hasn't been sunny. I would like to be able to go on longer trips. I can borrow my brothers 2400 generator any time but even though it's a "quiet" one I hate making noise. I think it disturbs the peace for us and for others. If the toaster oven "dies" it might not get replaced Shadrach