House batteries

[scrubjaysnest]

Originally Posted by Techn0

So according to Trojan's User Guide and that diagram, I can discharge my new T-125s down to 20%. That would give me 392 amp hours of battery. Okay, works for me. I will see if it lasts for that many cycles. Hopefully lithium is mainstream before I have to replace them again.

For maximum life expectancy don't go below 50%. Trojan's typically last 8 to 10 years with proper charge discharge cycles and not going below 50% DOD.

[Oneilkeys]

Originally Posted by scrubjaysnest

For maximum life expectancy don't go below 50%. Trojan's typically last 8 to 10 years with proper charge discharge cycles and not going below 50% DOD.

That's true, however maximum life expectancy may not be the thing you want most out of your house batteries. I am more than willing to trade some longevity for the ability to draw down my batteries to 30% or so - when I need to do so to avoid running my generator. The question for me is how much "life expectancy" am I losing? It's not a black or white issue for me. Similar to not driving your RV above 55 mph. That will give you maximum gas mileage and RV life expectancy, but not many (most?) of us are willing to do that because it significantly increases our driving time.

[Chance]

According to Trojan data, you should expect around 1,200 cycles at 50% DOD, and around 3,000 cycles at 20% DOD.

If the goal is solely maximum battery life expectancy, why not limit depth of discharge to 20% instead?

The difference I see is that one scenario spends more money up front, while the other spends it over time with more frequent battery replacement.

But even differences in total costs shouldn't be the main decision driver because it's not that significant on its own. As a rough example, do the math between 2 batteries that may last 1,200 cycles versus 4 batteries that last 3,000 cycles and the difference can be less than a tank of gasoline for your motorhome. And is it that important if it occurs every 5 years or longer? It wouldn't be to me.

In my opinion battery bank capacity and planned depth of discharge should be selected based on balancing all system needs. There are a lot of factors to consider when designing most anything.

[allantodd1]

I wanted to increase battery capacity. I have two 12v factory installed batteries in my new Hurricane 34f. I added 2 6v batteries.

The two 12v batteries are running in parallel (positive to positive and ground to ground) and I hooked up the two 6v batteries in series (1 hot to 1 ground connecting the two batteries). I then connected then 1 unused positive on the 2 6v batteries to the positive on the 12 v batteries and the same with the negative)

This I think is correct everything seems functioning correctly so far. Does this sound like the correct hook up ? Any issues ?

Any advice appreciated !

[mustang94]

Originally Posted by allantodd1

I wanted to increase battery capacity. I have two 12v factory installed batteries in my new Hurricane 34f. I added 2 6v batteries.

The two 12v batteries are running in parallel (positive to positive and ground to ground) and I hooked up the two 6v batteries in series (1 hot to 1 ground connecting the two batteries). I then connected then 1 unused positive on the 2 6v batteries to the positive on the 12 v batteries and the same with the negative)

This I think is correct everything seems functioning correctly so far. Does this sound like the correct hook up ? Any issues ?

Any advice appreciated !

Sounds to be hooked up right but only one thing wrong. You never hook up old with new. Unless your original batteries are new and your 2nd two are exactly the same. Odds are the new batteries are better with more amps and all but they are now only as good as the weaker 2 and may not ever get a full charge. Not sure but now you may have shortened the life span of all 4. I am no expert but you might want to do some checking.

[Oneilkeys]

Originally Posted by allantodd1

I wanted to increase battery capacity. I have two 12v factory installed batteries in my new Hurricane 34f. I added 2 6v batteries.

The two 12v batteries are running in parallel (positive to positive and ground to ground) and I hooked up the two 6v batteries in series (1 hot to 1 ground connecting the two batteries). I then connected then 1 unused positive on the 2 6v batteries to the positive on the 12 v batteries and the same with the negative)

This I think is correct everything seems functioning correctly so far. Does this sound like the correct hook up ? Any issues ?

Any advice appreciated !

Sounds good. While it is generally not advisable to add new batteries to an existing older battery bank, nor it is best practice to combine 12v and 6v batteries in the same bank, you can do it. The life span of the new batteries probably will not be as great and the overall voltage you can charge your bank to may not be as high - depending in how good shape your 12v were in the first place. But combining the two 12v in series gives you one 12v to add to your 2 battery 12v bank and that is OK.
Since you already had the two 12v and you wanted to add battery capacity at the lowest cost, what you did is probably the lowest cost/best case in this instance.
I would buy a good hydrometer and routinely check the two 12v batteries to make sure they are holding up.

[allantodd1]

Originally Posted by mustang94@hot.rr.com

Sounds to be hooked up right but only one thing wrong. You never hook up old with new. Unless your original batteries are new and your 2nd two are exactly the same. Odds are the new batteries are better with more amps and all but they are now only as good as the weaker 2 and may not ever get a full charge. Not sure but now you may have shortened the life span of all 4. I am no expert but you might want to do some checking.

Thank you.
My coach is new.
All batteries are new so that might help me. Would you advise to do away with 2 12v and replace with 2 6 v. That would give me 4 6v.

[allantodd1]

Thank you.
My coach is new.
All batteries are new so that might help me. Would you advise to do away with 2 12v and replace with 2 6 v. That would give me 4 6v.

[allantodd1]

Thank you.
My coach is new.
All batteries are new so that might help me. Would you advise to do away with 2 12v and replace with 2 6 v. That would give me 4 6v.

[Oneilkeys]

If you have two new 12v and two new 6v, I would run with what you have. It doesn't make much sense to throw out new batteries to make things match. You will probably not gain much for a large cost.

[bigben]

I spent a fair amount of time last year doing the math to calculate what we'd need to dry camp with quiet time from 11:00 PM to 7:00 AM each day (no generator running). Experience told me that 2 Trojan 125 were marginal for making it through quiet hours. So we upped the battery set to 4 Trojan 125. Since that time we are good to go.

A couple of reference points. We have a Whirpool TMNF and a CPAP machine that we will run all night. We often will watch TV via a VIP 211Z until about midnight. We dry camp under these conditions for up to 3 months per year.

Lessons learned.

1. Once our invertor hits 11.8 volts it automatically faults out and shuts off.

2. Run the generator for 3 hours to fully charge batteries back up. Try to run gennie from 7:30 PM to 10:30 PM for this purpose.

3. I don't like to use a pony external generator so I change my own oil, oil filter, air filters and spark plugs by standard (150 for oil and air - 500 hours for plugs).

Hope this helps.

[mustang94]

Originally Posted by bigben

I spent a fair amount of time last year doing the math to calculate what we'd need to dry camp with quiet time from 11:00 PM to 7:00 AM each day (no generator running). Experience told me that 2 Trojan 125 were marginal for making it through quiet hours. So we upped the battery set to 4 Trojan 125. Since that time we are good to go.

A couple of reference points. We have a Whirpool TMNF and a CPAP machine that we will run all night. We often will watch TV via a VIP 211Z until about midnight. We dry camp under these conditions for up to 3 months per year.

Yea I am in the same boat right now, running different this in MH to see the amp draws for day time use and then for night time use. I just ordered two T125 Trojans to see how they hold up over night at first. after some time of testing this out I am going to add two more and think that will do the trick. But I think my Gen time will be close to 4 hours of running first thing in the morning. But only a matter of time to find out.

[mustang94]

Originally Posted by allantodd1

Thank you.
My coach is new.
All batteries are new so that might help me. Would you advise to do away with 2 12v and replace with 2 6 v. That would give me 4 6v.

Even though my (own opinion) would be not to mix 12 and 6 volts together but they might work just fine for now. Me, if money wasn't a issue, I would go with all 4 being the same 6 volts. Not sure if your two 12 volts have the same amps as your two 6 volts. I think this is where the problem might fall. But like most peeps here I am also learning. Would love to hear from you again in a year or two.

[bigben]

Don - yep. All the math gives you and idea where you need to be but use will tell how good your math was. With the 4 Trojans - we are in a good spot. And yep, 3 hours is the minimum to bring the batteries up to full charge. I will do that generally twice a day. Funny though, we were in a military famcamp and at midnight the generator came on - almost got put into timeout before I could get up and shut the AGS system down.

Best thing I did was put a Pro-Fill system on my batteries. Now I carry a 1 gallon jug of distilled water, pull it out once a week, pump the ball until it won't compress and batteries are all topped off. Best adder we've put on to the 4 batteries.

[mustang94]

Originally Posted by bigben

Don - yep. All the math gives you and idea where you need to be but use will tell how good your math was. With the 4 Trojans - we are in a good spot. And yep, 3 hours is the minimum to bring the batteries up to full charge. I will do that generally twice a day. Funny though, we were in a military famcamp and at midnight the generator came on - almost got put into timeout before I could get up and shut the AGS system down.

Best thing I did was put a Pro-Fill system on my batteries. Now I carry a 1 gallon jug of distilled water, pull it out once a week, pump the ball until it won't compress and batteries are all topped off. Best adder we've put on to the 4 batteries.

A battery fill system runs about 150 bucks, not really sure if that would be worth it. It still take you out there to do the filling, just makes it a little easier. Hhhhmmm... have to let me know how well it works for you.

[scrubjaysnest]

Originally Posted by allantodd1

Thank you.
My coach is new.
All batteries are new so that might help me. Would you advise to do away with 2 12v and replace with 2 6 v. That would give me 4 6v.

Mixing battery types is never a good idea. The chemistry is different so they charge/discharge at different rates. If your 12 volts are the unknown junk that came with ours then scrape them.
You can certainly get by with mix and match for the short term but loosing the whole system in the middle of the night goes up. They won't fail at a convenient time.

[bigben]

Battery fill solutions are on sale now at a couple of places - runs you about $95. If you got a solid plan for maintaining, no issue. If you lose a battery or 2 due to let them go dry, $100 is a good bargain. I just wanted a way to once a week top off all batteries at once with out using a fill jug on 12 different times. Just my way of making sure the job gets done.

[Techn0]

Originally Posted by bigben

Battery fill solutions are on sale now at a couple of places - runs you about $95. If you got a solid plan for maintaining, no issue. If you lose a battery or 2 due to let them go dry, $100 is a good bargain. I just wanted a way to once a week top off all batteries at once with out using a fill jug on 12 different times. Just my way of making sure the job gets done.

I have the Trojan Hydrolink on the way in the mail. I was able to find the 24v for $155 with pump. I know you can find the Flow-Rite for less; however, Trojan said that anything other than their proprietary fill device would void the battery warranty. Go figure.

[samven]

One thing that everyone probably already knows but might help a new person, that is that your battery voltage to determine charge state is with a resting disconnected battery. If your inverter is on and your battery voltage drops to 11.8 when the inverter kicks out your battery will probably recover to something over 12v. If you have your system set to start the generator at 12v you are most likely only down to 70% charge. If you need the most time from your inverter set the system to start the genny at the same time your inverter kicks out. You will still not be below the 50% discharge level and your starter will not be competing with any load from the inverter as the load from the starter will drop the voltage to inverter kick out if it has not already and as soon as it starts the inverter will come back on line.

[wredman]

I have a Hurricane, with 2 batteries. How long would it take the generator/charger to charge the batteries if they drop to about 11.4v. I have my AGS set for ~11.6 now but it was set too low from the factory. The batteries were low on water too. The gen runs for a little over an hour and seems like the batteries are draining pretty quickly for the light load I am putting on them ( house lights and sometimes the radio). Thinking the new batteries may be damaged already.