adding second battery

[aatauses]

Our Bh 3670 came with only one battery, but does have an additional battery box. My question is what type of battery do you recommend for the second battery? How do I connect the cables (I know positive to positive, neg to neg), but asking about the type of cables and how they connect to the existing battery? Do I need some type of special clamp or just a "flat" on the cable and put it "under" the current configuration on the existing battery? Anyone who has a picture of the clamping configuration would be helpful. any additional information is always appreciated.
thanks
al

 

[gmc]

You really should replace both batterries at the same time. I just replaced both of mine in my bighorn, with two agm31's. kind of pricey but well worth it to me. your cofiguration will work, as that is the way I have mine wired. also the two batterries should be of the same make

 

[donr827]

We are in the process of purchasing a 3055RL Big Horn. When I was talking to a customer service person at Heartland he told me that they do not provide the option of adding a second battery. Not sure why. I will add the same group battery when the trailer arrives. I hope it comes with the wiring in place to add the second battery.
Don

 

[danemayer]

Auto parts stores carry a selection of battery cables in different lengths. I went to an O'Reilly store and got cables like this. The cables have different connector types on each end. Your batteries should have both types of mounting posts.

 

[PeternLiane]

I'll see if I can take a picture of my set up next week for you. I do like the double set up.

 

[slmayor]

We removed the plastic battery box, reinforced the floor of the compartment and replaced the single 12v with 2 6 volt AGM's. Sealed, so no box needed. As Butch said, they're pricey, but worth it, both in terms of ease of maintaining them and length of use.

 

[lorax]

After our first year of traveling, I added a second 12 volt battery in parallel. The pair would not charge beyond the weakest (old) battery. I have since replaced these batteries with 2 six volt batteries in series. The two six volts are way better.

 

[pegmikef]

Yep, I too use two six volt batteries (Trojan 105s). More amperage for your buck.

 

[danemayer]

Here's a photo that shows the 2 types of mounts. I bought 18" cables and in retrospect probably should have bought 9" cables.

 

[donr827]

Here's a photo that shows the 2 types of mounts. I bought 18" cables and in retrospect probably should have bought 9" cables.
View attachment 17642

Still I nice job. Better too long then too short.
Don

 

[lhetsler]

I am considering putting in 2 - 6 volt batteries in my bighorn as some of you have done. I am wondering will the stock converter/charger still be okay and the charging from my truck at 14.4 volts be okay since the batteries hooked in series will equal 12 volts. Who can explain why this is okay, anyone.

 

[Rickhansen]

I am wondering will the stock converter/charger still be okay and the charging from my truck at 14.4 volts be okay since the batteries hooked in series will equal 12 volts. Who can explain why this is okay, anyone.

You obviously understand that when two 6 volt batteries are in series are seen as a 12 volt load, so I'll try to use that as a premise.

Your convertor (or truck charging system) produces 12 volts, and at some maximum current - Your convertor is likely 60 amps maximum. How much current (load) a battery represents is based on the voltage applied to it. Just opposite as when two 6-volt batteries are in series they produce 12-volts across the two, when 12-volts is applied the voltage divides across the two. The current going to the batteries is determined by the voltage applied to them.

In a 12-volt charging system, the charge voltage is normally 14.4 volts at a high rate charge. With two 6-volt batteries in series the same 14.4 volts is applied, but each battery only sees 7.2 volts.

In this example, if everthing remains static and one battery is a 10 amp load, two batteries certainly is a 20 amp load, right? But, charging systems are regulated. As they approach their current limitations, they back off on the voltage to maintain the charge rate (current) below their maximum. There are other limitations, like cable sizes and fuses to consider, but almost all convertors or vehicle charging systems will handle multiple battery strings.

 

[CliffP]

I'll see if I can take a picture of my set up next week for you. I do like the double set up.

Did you have to buy 2 new battery boxes? Our original box isn't tall enough for the GC type 6 volt batteries. Will have to buy both boxes when we do the mod.

 

[PeternLiane]

Did you have to buy 2 new battery boxes? Our original box isn't tall enough for the GC type 6 volt batteries. Will have to buy both boxes when we do the mod.

I bought two battery boxes. I have seen a battery box that will fit two batteries.

 

[CliffP]

I bought two battery boxes. I have seen a battery box that will fit two batteries.

Do the batteries sit side by side in that box?