4104 Owner Battery Question

[siberyd]

Greetings All,

I am having some start battery problems and got to wondering a few things:

1. What size start battery or batteries on your coach.
Mine are 2 - 4D batteries with 1000 CC amps.

2. What size house battery or batteries?
Mine is 1 - 8D battery with 1200 CC amps.

I seem to have a battery drain when all switches are off. My saturday project is to track it down.

Thanks in advance.

Siberyd

[Lin]

2 4D batteries should be more than enough for your start batteries.  There are many the use 2 groups 31's.  You could try turning off your battery disconnect if you have one to see if they still drain, or put an ammeter to them to see if there is a draw while things are turned off.

The size of the house bank would depend on what you are using it for.  Is the 8D you are using for that deep cycle?

[siberyd]

House battery is not a deep cycle, just a standard 8D battery. My PO had it set up that way so I have not changed it out yet. It will be a future purchase when we start using it more than twice a year.

Siberyd

[gus]

Lin is correct, I have two Gp 31s starts, which are smaller than the 4Ds, and they are more than enough in moderate climates.

I have separate, inexpensive "green knob" cutoffs on all my batteries, makes slow drain problems or electrical work much easier to handle.

Baggage compartment lights are a good place to start looking for leaks.

[zubzub]

One group 31 will start my 6-71 even in the fall.  As far as the power drain is concerned that will take some time, any one of the many ancient relays could be stuck along with dozens of other possible shorts etc... I would start by checking out the main On switch and associated relays.  Hardest thing to trouble shoot on my 4104 is 'lectrics.

[TomC]

I have 2-31's to start (8V-71) and 2-8D's for house. The AGM 8D's are rated for deep cycle and starting. I have a jumper solenoid that connects the deep cycle to the starting batteries mainly to charge the deep cycles going down the road (since my refer is electric). I have started the bus on the deep cycles when the starting batteries have failed-also helps when the weather is cold. Nice to have the redundancy. Good Luck, TomC

[gus]

I have the same setup as Tom, can't really imagine any reason not to have this kind of hookup.

It has saved my bacon more than once.

The main reason I have two starts is for backup, I've had one start fail a couple of times and the remaining one saved me. It also helps in cold weather but I don't often travel in cold weather.

However, when one shorts out it usually kills the other one also. Had this happen too!

When ,y 4Ds fail I'm going to Gp29 or tractor batts since they are easier to find around here than Gp31.

[siberyd]

Still working on tracking down my short. In the process I have found a solenoid mounted to the bulkhead and a jumper clip. Following the wire it goes to the start batteries.

Now to track down the short.

The group 31 batteries cost the same as 4d. I work in a town that is one of the major trucking areas in southern Calif.

Siberyd

[Mex-Busnut]

I claim to know absolutely nothing about 4104's, other than that they were made by GM and are awesome-looking old buses.

Let me emphasize what another mentioned above. It is important to have master cutoff switches for both battery banks. That is the only way to keep "phantom loads" from draining them. Also, with all systems shut down, and the master switch open ("Off"), you can temporarily place an ammeter across the switch and know that something is still drawing current somewhere.

I found some of these switches on Ebay® with postage included from an Australian dealer of parts for boats much cheaper than the price on the shelf at camping supply places. Do a search on Ebay® for "battery disconnect switch" and "battery cutoff switch", so you can get some ideas. The ones I got are rated at 450 amps, if I remember correctly.

[Kevin]

Hey Jon,

My '04 came from previous owner with (2) 8-D start batteries and (6) deep-cycle 12 V house batteries. I've replaced the 8-D's once and swapped out the 12 V deep cycles for 6 V deep cycles, which I'm told yield greater amp hours. I've been pretty happy with this set-up.

Kevin

[Kevin]

Jon,

Forgot to mention... my coach too is equipped with master cut-off switches on both the start and house batteries. It is cheap insurance and I usually switch 'em both off if I don't operate the Ol' Mare for more than a couple of months...

Kev

[luvrbus]

Texas Industrial Electric has everything one need to make a good battery disconnect system I would not be buying the junk from WM myself check out the new battery separators they will automatic disconnect from a low battery to protect a good battery pretty neat then they sell good manual disconnects.

You get what you pay for that is not a place to cheapen up IMO www.texasindustrialelectric.com

[gus]

Siberyd,

That jumper is probably the PO's easy way to connect house and start batts instead of using some kind of switch. Just a guess.

Kevin,

You don't need 8D starts in a 4104, way overkill. The original reason they were used was to run the huge fan for the heat/AC system and because the bus had a generator instead of an alternator. Gp 31s are plenty big for starts. They might be needed if you use the bus in super cold weather, but not otherwise.

House batts depend completely on your bus use and your house elect system, everybody has different needs.

I've used the cheap green knob batt cutoffs from WM for many years and had only one fail because of too much side load from the cable. I use them in every vehicle I own including farm tractors, probably 25 total. There is one knob type that comes apart when the knob is loosened, but the green ones stay together.

[Kevin]

Thanks, Gus, for the info!!!

Those 8-D's are b@!! breakers to heave in an' out! Not cheap either... plus if I can shed a few additional pounds, I may be an eyelash faster on those Ol' 4104 w/6-71 uphills! Yeee-Haaaa!!!

Kevin

[gus]

8Ds also have the poorest warranties of any other batts. They simple are not necessary for a conversion, especially if you have converted to an alternator-an easy thing to do.

One good thing about a 4104, it will climb mountains all day long without overheating, you just have to learn to shift down into a lower slower gear and enjoy the scenery. There is one place coming SW out of Ruidoso, NM  where I drove it five-seven miles uphill in second and third at full throttle, never made one complaint.

If you lug it on hills it will overheat and die an early death.

I've crossed the Rockies and most other western mts numerous times plus all the eastern ones as well and never had a problem. I put 75,000 miles on it in five years.

My single complaint is that first gear is too high, always had to be careful not to stop on an uphill incline. It will go but it is murder on clutches.