8D Deep Cycle AGM questions

[buswarrior]

You don't stay young for long, and 8D batteries speed up the aging process.

If you can figure out how to fit 4 Group 31 batteries, do your future-self a favour now, and make them fit now.

Group 31 are the batteries of choice for the big trucks. Same as golf cart batteries, competitive, plentiful, lots of suppliers, and prices stay driven low.

happy coaching!
buswarrior

[windtrader]

Oops, sorry Scott. Yes, thread drifted to house batteries. Last week I replaced my start batteries (2 8D monsters) for two Group 31 start batteries. They fire up the motor really fine when the house and start batteries are connected via a switch in the battery compartment. When the motor starts on its own start batteries, it kicks but I concur with Clifford that having 4 Group 31 offers a lot more CCA to kick the motor over. I'm going to keep things as is for now as it works fine having the house back up the starts.

[muldoonman]

That's what I have in mine for start (4) group 31's. Thinking about AGM's next time as I have a couple 8D's under coach and those have been trouble free for about 3 years and like the fact that you don't have to check water level in those puppy's. It's a pita to remove hold downs to just check water on my start batteries.

[rusty]

I am 3 years into a set of 6 L-16 fullriver batteries. I have not had any problem with them but I am not hard on batteries, do not boondock a lot. Will see in 3 or four years.

Wayne

[luvrbus]

He needs to look past a deep cycle battery for starting no matter what brand he chooses,I pay $89.99 for group 31's at my local Batteries and Bulbs and I paid $40.00 for a friggn lawn mower battery at Napa 

[Oonrahnjay]

He needs to look past a deep cycle battery for starting no matter what brand he chooses ... 

      Can't put it any plainer than that.  Deep-cycle batts aren't made to be start batteries, won't do the job very well, and will likely be damaged by the stresses of using them for starting.  Just don't.  You could look for a very good alternative -- if you search really hard, you could probably find an excellent battery for starting your engine -- check for the ones marked "start battery". 

[buswarrior]

Re: the mysteries of battery types and starting the engine...

Some time ago, a few peeps, Sean Welsh was one of them, were pondering just building a coach with a big house bank and calling it a day.

With the size of house bank that some of us carry, it was figured that the start load is not going to do anything harmful, and carrying and maintaining/replacing batteries and associated duplications of charging/combiner equipment, that basically do nothing that the rest of it could readily do, was a cost and complexity that could be avoided.

Yes, you lose redundancy, blah blah blah, the school of thought was, if you end up with dead batteries, it's your own fault and the predicament is part of the punishment for being foolish?

One battery bank, one engine alternator, one solar charge controller, one inverter/charger.

Job done?

Who knows how to alert Sean from his marine pursuits to revisit the coach board for some current thoughts?

happy coaching!
buswarrior

[luvrbus]

I don't recall Sean having just one battery bank ,I seem to recall he had some G27's for the starting of his 8v92, if Scott has the 42 MT starter that is a high amp draw starter like 800 amps for the 24v system 

[eagle19952]

I don't recall Sean having just one battery bank ,I seem to recall he had some G27's for the starting of his 8v92, if Scott has the 42 MT starter that is a high amp draw starter like 800 amps for the 24v system 

he didn't...
but he later wrote that he should have.
i did, and do.
one battery bank since day one.
my generator has it's own battery
and i have some really nice jumper cables
and coach-net or progressive road service will send a jump start.
i get about 5-6 years out of my batteries.
all of my 110v outlets are sub panel off the inverter/charger
i have no propane
but, i am 12v.
not sure i would do this 24v.

[windtrader]

I know nothing about battery design but one of the key differences between start and deep cycle design is the lead plates are thicker in deep cycle batteries. The start batteries use thinner plates to get more CCA.

What is most reported is using start batteries as deep cycle. The lifespan is shortened as the thin plates are not designed for deep cycling.

It seems if you have sufficient capacity (CCA) in the house deep cycle bank, same as the starts, then it doesn't seem there is harm to them, short or long term.

One key factor affecting lifespan of deep cycle batteries is DOD (Depth of Discharge). The deeper you draw them down between recharge the fewer cycles you get. Since start is a very quick event, I don't think DOD would be an issue. That assumes you have plenty to start with.

[Scott & Heather]

Guys, several threads on the site about using a single house system that can start your coach. Bob of the north discussed it and several have done it. That's what I want to do.


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[luvrbus]

Scott, people do it different ways I don't care for the 1 battery bank myself and the problem people never talk about is the AGM batteries require a higher rate of charge than a conventional automotive charging system does.  
Without the high dollar regulator the 8D's will never be fully charged unless your are plugged in with a good charger.
I have sit in on several battery manufactures seminars and a few of Dick Wrights seminars,not a 1 recommends the single bank system for a RV . Food for thought your bus being a DDEC ll no way would I go to a single battery bank what can happen will happen with a DDEC and the ATEC so it is a roll of the dice for you 

good luck        

[buswarrior]

Perhaps the difference is being a full timer vs weekend/monthly roadwarrior?

Systems under constant supervision.

If the parts don't match, battery type, charge rates, then the whole thing is a waste of time.

If nobody on board has "Battery OCD" then redundancy is required.

And with only one system, maybe more peeps on board might take an interest?

The discussion is a good one to have, so long as peeps know what they are doing, and have the correct equipment set up, there is no need for all these different battery systems and their associated ongoing costs to maintain.

I know peeps who connect the DDEC to the house system for that very voltage issue....

"Traditional thinking" comes from the herd's collective stupidity, defended against?

Buck the trend! save money, be different, be smart?

happy coaching!
buswarrior

[luvrbus]

Keep in mind his DDEC ll is 12v only not like Bill's DDEC IV which is 24v, they give enough problems on a 24v to 12v step dwn system without creating 1 IMO

[Scott & Heather]

Good advice for sure. I know it's outside the box, but it seems silly to and I quote "have a $400 set of batteries that only get used a few seconds every couple of months when it could all be part of a house bank"


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