M1078 Battery Conversion

[BERZERKER888]

 

[Lugnuts]

Southeast Pamlico Volunteer Fire Dept in NC has a M1083 with the 4 6TL batteries which we would like to convert to two batteries. You mentioned using group31 commercial batteries, but what cranking amps are needed for reliable operation?

RonMar said well. I personally use an Interstate threaded Lugs/ They have a 1000 crank amps a piece/ Without looking I think the cable is 2/0 on both hot leg and ground/ No trouble whatsoever.

 

[dsl]

Thanks for the information, the 4 6TL's are four years old and sitll doing the job, but when they go we will do the conversion .

 

[dsl]

Thanks for your reply, when the four year old 6TL's give up we'll convert to two group 31's

 

[Ronmar]

You can drop to two batts at any time, simply lift the battery leads off of the terminals of either the forward or rear pair of batteries and insulate those connections. Unless you are running the 260A alt, four 6t batts can be really hard on that very ecpensive alt. 2 batts are a much better match for the alt and it will have a much easier time keeping just 2 of them charged with limited run hours, without them overloading/stressing the alt...

 

[Lugnuts]

One last though I'd like to add since you are Fire Services related, since the truck isn't always running with the extra room you can install on the back wall a small 2 lead battery charger {3 or 6 amp) and install the 110 vac plug where the NATO connection is. If you want an Auto Eject you can go higher up on the bed. With the charger, batteries really get prolonged life and stay desulfated if the charger has that mode. Amazon sells them pretty reasonably or a marine charger company. Just a suggestion to take into consideration.

 

[Ronmar]

Yep, the biggest killer of batteries is low state of charge. In meeting the cold crank milspec without properly sizing the alt to support so large a battery bank, they set up a situation where the batteries have trouble reaching full charge unless run very long hours. Depleted batteries keep the alt in a state of regular overload… Lugnuts suggestion is a good one on any vehicle that sits far more than it is run, either a constant float charger, or a regular schedule of connecting a maintenance charger…|

just to be clear, when I say forward or rear IRT batteries in my previous post, I am refering to forward and rear on the truck. When facing the battery box, the batteries closest to you, furthest from the truck frame are the 0-12’s wired in parallel. The two batts closest to the frame are the 12-24s also wired in parallel, but placed in series with the outer pairs. So when facing the battery box, you would want to lift the leads on either the left or the right pair of batteries. There should be a diagram on the underside of the box cover…

This being an emergency vehicle, you could also get fancy and create a reserve battery bank with the disconnected batts, using a manual disconnect switch to separate the battery pairs, and a DC-DC charger. Whenever the truck is running, and the DC-DC charger sees >13.8 on its input, it will feed a set charge current(15-20A) to the second set of batts if they need it. This will limit overload on the alt and also help maintain the second set of batts. Then if someone forgets and leaves the lights on or some other issue occurs, you can easilly connect the isolated backup set to start the truck quickly…

 

[coachgeo]

One last though I'd like to add since you are Fire Services related, since the truck isn't always running with the extra room you can install on the back wall a small 2 lead battery charger {3 or 6 amp) and install the 110 vac plug where the NATO connection is. If you want an Auto Eject you can go higher up on the bed. With the charger, batteries really get prolonged life and stay desulfated if the charger has that mode. Amazon sells them pretty reasonably or a marine charger company. Just a suggestion to take into consideration.

@dsl will add a thought..... on the engine add a block heater. Yeah you are in NC I know.... honestly though diesels are "heat" engines.... little pre-heat and they start soooooo easy with less wear on the engine, starter, and more. You can get thermostatic 110v switch wall plugs . it would turn block heater on for you... Being fire service you can get break away plugs sockets too like they have on the Ambulances.

Amazon.com : plug in thermostat switch

 

[dsl]

@dsl will add a thought..... on the engine add a block heater. Yeah you are in NC I know.... honestly though diesels are "heat" engines.... little pre-heat and they start soooooo easy with less wear on the engine, starter, and more. You can get thermostatic 110v switch wall plugs . it would turn block heater on for you... Being fire service you can get break away plugs sockets too like they have on the Ambulances.

Amazon.com : plug in thermostat switch

 

[dsl]

The truck is in a heated fire station and has an on board charger with a self ejecting plug. It has a disconnect master batteery switch with a warning buzzer on it to prevent the batteries being left on. It carries a one thousand gallon water tank with a gasoline powered pump, and is used for brush fires and high water rescue. It is started and checked out once a week., and the batteries are never run down.

 

[tennmogger]

Under those conditions, your 6TL batteries will last for many more years.

 

[Peter Pszonowsky]

I know I’m late to the group but just got one for my Fire station , could you walk me through doing the group 31 batteries, great video just could see what or where you did with the wires, thank you in advance.

 

[Lugnuts]

Did you understand how to install the batteries? Are you just having trouble with the main cables?

 

[Peter Pszonowsky]

Did you understand how to install the batteries? Are you just having trouble with the main cables?

Would like a diagram . Other people are telling me I can't do it. Just want to do it right. The install I'm going to do it the same way you did with the bracket. Thank you very much for the quick response .

 

[Ronmar]

To put two batteries in series? See below…

the other people telling you you cannot do it are wrong…

This drawing applies to an A0. An A1 will have the 12 and 24v batt connections going to the manual and remote disconnect switches, then off to the connection points indicated.

the main chassis ground connection(braided strap) is made at the starter motor housing, where the ground cable from the batteries connects.

this drawing does not show the nato plug connections which would connect to the ground/- and to +24 terminals at the batteries…

 

[Lugnuts]

Would like a diagram . Other people are telling me I can't do it. Just want to do it right. The install I'm going to do it the same way you did with the bracket. Thank you very much for the quick response .

RonMar gave a schematic/ now at the batteries you have 3 cables coming to the boxes/ Remember the forward battery (the one at your left when you are looking at the batteries) is the 24 volt dc positive connection/ the rear 12 volt battery is for the 12 volt dc positive battery connection. In the video it says how to verify the 12 and 24 volt cable/ I will mention that at the alternator on the case it also tells you which is the 12 and 24 volt connection/ Verify your wires like it says and shows in the video / The negative side of the batteries are closet to you/ It will show you on the case of the battery which side is negative and which side is positive/ The jumper cable is as RonMar states and his schematics show it/ This is how you get the 12 volt side and the 24 volt side/ I don't know what your knowledge level and skills are so I say it as simple as I can. If you are still lost then I would suggest that you install the batteries as shown and then bring in and pay someone to help with the hookup/ Any more questions we can probably go To personal messages and clarify.