? deep cycle battery

[almo]

I am looking for a good "true deep cycle battery" for my 5ver. Not the cheapest and not the most expensive. Any ideas

[DennisG01]

Wanna stick with a wet cell?

I work part time at a marina - we've sold Deka there for years and years. They've been a solid performing battery. I use them on my personal boats, as well. Plus, they're made locally, which is always a nice thing.

Are you thinking group 27 or maybe larger? What do you want to be able to do with it?

The best thing you can do for your batteries is keep them on charge all the time (and check fluid, depending on type). Use a maintainer (if your RV doesn't have a built in charger) like the Battery Minder Plus - it also desulphates.

[richp]

Hi Almo,

If your battery compartment is suitable and weight is not an issue, then consider Trojan golf cart batteries. I believe it's the T-104 series you'd be looking for.

They are six volt, so you have to have two wired in series. But they are designed for deep cycling and IIRC they are 220 amp-hour rated. That means you can draw something in the neighborhood of 100 amps out of them for years without damaging them by exceeding the 50% discharge limit.

This has been my solution for the last 15 years (coupled with 140 watts of solar on the roof) and I'm totally satisfied.

FWIW.

[EdHale]

I used to live in a golf cart community in Georgia before I started full timing. This question of battery discharge has been in my mind for a long time so I wrote a note to Trojan to get their position since they make one of the best golf cart batteries around, IMHO. The following is my note to them and the response from one of their Product Engineers. This response was dated October 2010:



Trojan Battery Response

Dear Ed:

Thank you for submitting your question regarding Technical - Battery.

Based on your comments below:

I have been using your T105 batteries for years in my golf cart (Peachtree City, GA). Being a golf cart community the cart gets a lot of usage around town. I now have a 5th wheel trailer and installed two T105's in series vs the single 12v battery that it came with. All works great. My question has to do with degree of discharge. On the numerous RV forums the opinion seems to be that if you run a battery down to lower than 50% capacity, it destroys battery life. On my golf cart I, and many others in Peachtree City, run their carts down to the level they won't move. With my cart having six batteries I don't know what level this is, but it is obviously low. What is the official position of you, the manufacturer, on discharge level vs battery life/damage. I'm tired of listening to "experts" online that probably know less than I do. Thank you very much for your response.

Below is Trojan Battery's response:

We never want you to discharge your batteries below a 20% state of charge (80% depth of discharge). For a 36 volt system of batteries this would mean you never want to go below about 35 volts. The voltage of 34.9 volts is an open circuit voltage, which means the batteries would be at rest. For your 12 volt RV system, a 20% state of charge would be an open circuit voltage of 11.6 volts. Thanks.

If you have additional comments or questions, please contact me at the information below.

Sincerely,

Stacey Delzeit
Product Engineer
Trojan Battery Company
sdelzeit@trojanbattery.com
678-518-7378

[richp]

Hi Ed,

What a nice diplomatic way of correcting the 50% discharge number I cited.

I've used 50% for decades because that was what I'd read in a wide variety of literature. It's even the number recommended (for repetitive discharge cycles) by the golf cart company I get my batteries from.

Granted the last set I bought was about 7 years ago. So if Trojan now says a much deeper discharge won't harm their product, so much the better for folks like us.

Have a good one.

[DennisG01]

For what it's worth, I was over at the shop yesterday and looked at the tag on a group 27 D.C. Deka (my boat is shrink wrapped right now - a little hard to check). It has a 200amp rating.

[EdHale]

I'm glad you didn't take my post as a shot at you Rich because it certainly wasn't. I have read on various RV forums for years that same 50% number you have heard and I just wanted to get the opinion of the manufacturer that I like the most. I just have seen too many golf carts, including mine, perform very well for long periods with batteries that almost certainly are discharged much lower than 50% frequently. I personally don't think I want to go as low as 20%, but there is a lot more useable capacity between 20 and 50 that I feel better about visiting if needed.