MEP-803A battery size

[csheath]

I have read and looked and measured and can't figure out how the listed battery will fit in my 803A. The Optima Red Top 34/78 specifications are within a fraction of an inch of a group 24. The best I can measure in my unit the battery can be no more than 6" wide and not hit the unused mount tab on the back of the engine. The specs I found on the 34/78 say it is 10" x 6 7/8" x 7 13/16" tall.

Here is a photo of my battery compartment without a battery installed.



A group 24 fits the plastic tray perfectly but the battery hits that mount tab on the engine and has to be leaned over having pressure on it. The group 24 is only 7" wide so i don't see how an 1/8" is going to make the difference.

 

[DieselAddict]

I've tried to put a group 24 in a 803 because I already had some laying around. I gave up after seeing how close the terminals were going to be to stuff I didn't want them to touch. It will not be easy to get them in there. I've tried.

Buy group 51 batteries and use the time you save not cussing to enjoy a satisfying beverage of your choice.

 

[csheath]

The 24s I used were marine cranking batteries and I don't have any terminal clearance issues. I just don't like having them leaned against the engine tab.

I am at Walmart and the group 34 or 78 are pretty much the same case size. The 51 doesn't have a lot of cranking amps and they only stock it in the extreme price range.

 

[DieselAddict]

You don't need big CCA batteries for these generators. Especially in Florida.

When I'm testing sets I use a set of lawn mower batteries. They have about 220 CCA and spin the unit over perfectly well. The batts in my 803 are Optima Red top group 51s.

 

[csheath]

EDIT: The Value Power group26 batteries died in a year. See post #29. I switched to two lawn tractor batteries and they have been more reliable and a better value.

I have some 270 cranking amp lawn tractor batteries in my John Deere, 99 Mustang, and my gate opener. They are a good value at 28 bucks apiece.

Just exchanged my 24s for some budget 26s. They are a little narrower and shorter and 2 inches shorter in length.

Adding: The group 26 batteries tucked right in and leave a little room all the way around. The 51 might have fit better but it was $109 vs $48. I am not planning to tie these down so I didn't check to see if the brackets fit.

 

[Daybreak]

Howdy,
The military specs
MEP-802A = Optima Yellowtop D51R
MEP-803A = Optima Redtop 34 or 34/78

Group Size	Length"	Width"	Height"
24	10.3	6.8	8.9
26	8.2	6.9	7.8
34	10.3	6.8	7.9
34/78	10.3	6.8	7.9
51R	9.4	5.1	8.8
78	10.3	7.1	7.3
Optima 34/78	10.06	6.94	7.88
Optima 34	10.06	6.94	7.88
Optima D51R	9.31	5.06	8.94

 

[csheath]

Howdy,
The military specs
MEP-802A = Optima Yellowtop D51R
MEP-803A = Optima Redtop 34 or 34/78

Group Size	Length"	Width"	Height"
24	10.3	6.8	8.9
26	8.2	6.9	7.8
34	10.3	6.8	7.9
34/78	10.3	6.8	7.9
51R	9.4	5.1	8.8
78	10.3	7.1	7.3
Optima 34/78	10.06	6.94	7.88
Optima 34	10.06	6.94	7.88
Optima D51R	9.31	5.06	8.94

This further illustrates my point. At least in comparison to a standard 34/78 case being the same as a 24. I didn't see any issue with height when I had the 24s installed.

The only thing I can figure is the Optima design in the 34/78 size allows that unused mount tab on the engine to sit in between the cylinder shaped cells.

 

[Daybreak]

Howdy,
I figure the group 24 battery is 1.1" higher

 

[Guyfang]

When properly installed, the battery hold down gear will keep enough space between the engine tab and a Optima battery.

The absolutely only time I ever saw anything happen between battery and engine tab was when three of 4 vibration dampers failed and the entire engine and main generator swung over to the right rear side of the generator set enclosure and vibrated a hole into the battery. A rather extreme case.

 

[csheath]

When properly installed, the battery hold down gear will keep enough space between the engine tab and a Optima battery.

The absolutely only time I ever saw anything happen between battery and engine tab was when three of 4 vibration dampers failed and the entire engine and main generator swung over to the right rear side of the generator set enclosure and vibrated a hole into the battery. A rather extreme case.

DOH! I didn't even think about using the tie downs to pull the 24s off the tab. At any rate, the 26 sits right in the hole without touching so I'm happy.

 

[Guyfang]

Sometimes, I know its rare, the Government does get it right!

 

[csheath]

Sometimes, I know its rare, the Government does get it right!

Right would have been installing a battery that sits flat in the space provided but this is a manufacturer snafu. Not the Government.

 

[Guyfang]

No, no. The Government designed the set. Or if not, agreed to the design. But I do agree, it could have been designed differently.

 

[Daybreak]

Right would have been installing a battery that sits flat in the space provided but this is a manufacturer snafu. Not the Government.

Howdy,
I must be missing something. The correct batteries fit fine. The hold-downs work fine. What is the problem?

 

[Guyfang]

Go back to post #10

 

[mackymola]

Hey I'm new to this mep 803a. I have a quick question. Why two batteries on the mep 803

 

[csheath]

Hey I'm new to this mep 803a. I have a quick question. Why two batteries on the mep 803

It's a 24 volt system.

 

[mackymola]

That means I have to get two 24 volt batteries?

 

[jamawieb]

That means I have to get two 24 volt batteries?

Two 12 volt batteries in series.

 

[mackymola]

Two 12 volt batteries in series.

That make sense now