If you look at the cca ratings carefully, you should find that a deep cycle battery does not have the short term high amp ablilty that a regular car battery has. Most of the "deep cycle" batteries at Walmart are marine or dual use batteries. The are inbetween a true deep cycle and a car battery. A true deep cycle will be the golf cart type batteries they sell at Sam's club, and are usually six volt though you can buy 12 volt ones too.

A automotive type battery is best for starting a vehicle. That's why they design and sell them for that use. Just like tires, a battery can be designed to be good at one thing(high amp starting), or it can be designed to be good at another(moderate amp deep drains), but it's hard to design one that will be good at both.

 

[QUOTE=bob_351]Actually, that's what I meant to say. I think I just worded it wrong. Thanks for the correction, Bob.

I had actually forgotten that RV's use the deep-cycle batteries too. Since a lot of older RV's were actually built on truck chassis and used the same engines, I'd say using one in a regular pickup would be fine.

 

From the 1980/89 Ford Truck Parts Catalog: Optional H/D battery's available for an 1984 F250.

Motorcraft BH-27-A 715 cold cranking amps.

Motorcraft BH-27-F 675 cold cranking amps.

The standard battery was a BX-64 (475 cca).

 

[QUOTE=Wild Karrde]But if you really check it out you'll likely find a conventional automotive battery starting the engine and a deep cycle mounted somewhere in the coach to power the lights, water pump, fans, etc.. A well set up unit will let the alternator charge the aux. battery but will not drain the starting battery.

As Franklin stated ... regular automotive batteries are made for short bursts of high energy and immediate recharge, deep cycle batteries are designed for a slow, steady drawdown to next to nothing and then total recharge.

If a deep cycle starting battery works for you, OK, it just isn't what it was designed for. Kinda like driving nails with a pipe wrench or loosening nuts with a pair of pliers ... it works, but it just ain't right.

I buy the biggest, highest CCA conventional automotive battery I can fit in the box.

 

In these trucks, you can easily fit a Group 31 commercial battery in the tray.
I run a single 1075 CCA(1300CA) one in my diesel, with a 210 minute reserve, you will find some marine deep cycles run similar ratings, but a commercial battery is designed for starting, and it's designed to handle heavy vibration, etc, and tend to last considerably longer.

 

thanks for all the help. I went to the store and got a 850 CCA regular batt with a 7yr warranty so im good to go.

 

The biggest reason I personally use the deep-cycle in my trucks is because I regularly run my lights off battery only. I've been in a lot of situations where I've needed my truck's lights at night for long periods, where leaving the engine running is not an option (enclosed areas, long run time, etc.), and will quite often run a fairly large power inverter directly off the battery.

That's just my situation, though. Under normal circumstances, a regluar battery would be fine. In fact, I'm actually thinking about making a dual-battery setup for my truck, one regular battery for day to day use, and the deep-cycle wired up to switch to when I'm needing a long duration of power consumption.

 

how would i wire a deep cycle batt for lights, radio etc. in addition to a normal starting battery?

 

Ford made a second battery rack for RV use or you could catch one from a donor diesel. Mounts on the forward driver side of the engine compartment. All the holes are there and there are provisions for remounting the radiator overflow/washer tank.

When I was running an 11'3" slide-in camper that's where I kept the camper battery. Isolation can be done electronically or with an A-B-A&B-Off switch.

Back in '01 we spent a few days dry camping up in the Rockies and I was amazed at how well the fifth-wheel camper's new battery was holding up. The spot we parked in was such that I just left the truck hooked up and it turns out I had forgotten to unhook the trailer light cord. In that cord is a charging circuit for the RV battery and it had all but sucked the truck battery dead.

Good thing Clyde fired off during the second slow, groaning revolution or it might have been a long walk.

 

Original Post I can't believe this thread has been here a week and no one has mentioned "Reserve Capacity".







<DT>Reserve Capacity <DD>A performance rating for automobile starting batteries. It is the number of minutes at which the battery can be discharged at 25 Amps and maintain a terminal voltage higher than 1.75 volts per cell, on a new, fully charged battery at 80degrees Fahrenheit(27C)</DD><DD>RESERVE CAPACITY What does the Reserve Capacity rating mean and how does it apply to deep cycle batteries? </DD>



ANSWER:
Reserve capacity is the number of minutes a battery can maintain a useful voltage under a 25 ampere discharge. The higher the minute rating, the greater the battery's ability to run lights, pumps, inverters, and electronics for a longer period before recharging is necessary. The 25 Amp. Reserve Capacity Rating is more realistic than Amp-Hour or CCA as a measurement of capacity for deep cycle service. Batteries promoted on their high Cold Cranking Ratings are easy and inexpensive to build. The market is flooded with them, however their Reserve Capacity, Cycle Life (the number of discharges and charges the battery can deliver) and Service life are poor. Reserve Capacity is difficult and costly to engineer into a battery and requires higher quality cell materials. For instance, Rolls, Surrette and Lifeline use thicker lead grids (the plate's skeletal structure) to support additional positive plate oxides which are compressed into a denser form in order to add battery reactive material for greater Reserve Capacity and Cycling Performance. In addition, these plates are separated by indestructible separators. These mats hold the active oxides tightly in place during the cubical plate expansion which occurs during deep discharging, instead of allowing the oxides to shed off and precipitate to the bottom of the battery. Construction materials such as those raise the Reserve Capacity of a battery and increase the battery's Cycle Life.



More info for you:


http://www.interstatebatteries.com/www_2001/content/products/ratings.asp

 

You are still talking about deep cycle batteries, which have a totally different use than a starting battery. Two different animals. If you take a regular car battery, and subject it to the same tests as a deep cycle, it will fail every time.

A deep cycle is as described above, very thick plates and heavy duty construction. But it does not do well with instantaneous high current draws.

A automotive battery is built with very delicate honeycomb type plates. This exposes more plate area to the acid, which gives it more capacity for short bursts of high amps. But the drawback to this is the plates are too delicate for long term amp draws and they can't stand very many heavy re-charges when they are drained down too much.

Will a deep cycle battery start a vehicle? Of course, people are apparently using them. Are they optimized for this use? No. When the going gets tough on a hot day, with a large engine, with a bunch of accessories pulling it down, I bet a starting battery will crank the engine faster than a deep cycle.

 

Obviously you would not use a regular trolling battery in a vehicle. They have the marine starting batteries which happen to be deep cycle. A man that likes to play his radio with the truck off needs the dual purpose type. That is unless they want to put in an isolator and a second battery. You can get a good balance between cca and reserve capacity, meaning the cca will be higher than came from the factory on the truck. I myself use the dual purpose until I have the time to setup an auxiliary battery. I am not saying it is the best battery for normal circumstances but it is great for a man playing his radio or for those who forget to turn the lights off.

I do agree that a 1000 cca starting battery is gonna be better than a dual purpose battery cranking a vehicle under most circumstances. The dual purpose will not have to be replaced as quick after you kill it a few times with the radio.

 

Actually, I guess I forgot to mention that mine IS a Marine-type starting deep cycle battery. I apologize for that oversight.