Do I Need a Battery This Big?

[geobar]

I just bought a used wheel loader that needs new batteries. The manual calls for two 4D size 12v batteries hooked in series - 24V. The batteries in the machine are Delco 729s with 950CCA and 250RC. These things are huge and must cost a fortune. Can I get away with smaller batteries with 1000CCA but perhaps not as high reserve capacity?

 

[DieselPower]

If it calls for two 4D batteries that's what I would put in it, that is what it is designed to use afterall. Downsizing batteries is usually not a good idea and just leads to hard/no starts at some point in the future.

 

[Dirthog]

You could put smaller battiers in it but you will not have enough reserve to turn the engine over properly see people try and do that all the time in my line of work and they end up buying the right batterys anyhow and a starter too cause they burnt that out trying to get the machine started believe me the batterys are at lot cheeper than starters!

 

[SPYDERLK]

Do I Need a Battery This Big?
No, unless it is hard to start. The economies of buying good high volume produced auto batteries should not be ignored. If the item cranks up like it should, no problem - money saved. If it doesnt, fixit so it does and keep it that way. The high delivery auto batteries will be fine.
Larry

 

[CurlyDave]

No, unless it is hard to start.

Of course it is hard to start.

Why else would he want new batteries?

Well, OK I once had two RV batteries crack their cases and leak acid. That was also a good reason to get new ones.

See if by some chance you can get the right batteries from Wally World, Costco, or on the internet. To me, the problem with other batteries is that they will fall below the minimum RC for starting the beast sooner than the right batteries. If they cost half as much but last 1/3 as long, you haven't saved anything.

Many times the internal construction of a heavy equipment battery is stronger than a seemingly comparable automotive battery. There is more shock & vibration in your loader than in a car engine compartment. But you knew that already from driving it.

 

[BobRip]

You could put smaller battiers in it but you will not have enough reserve to turn the engine over properly see people try and do that all the time in my line of work and they end up buying the right batterys anyhow and a starter too cause they burnt that out trying to get the machine started believe me the batterys are at lot cheeper than starters!

I agree with Dirthog. Smaller battery will spin the starter over slower and make it pull more current which generates more heat and this is hard on the starter. Also I have seen recommendations to up battery size when replacing (on cars and trucks). The connections and other stuff ages and you need a bigger battery. A smaller battery may start fine on a warm day when new, but put a year on it and a cold day and it is not as likely to start.

 

[SPYDERLK]

I agree with Dirthog. Smaller battery will spin the starter over slower and make it pull more current which generates more heat and this is hard on the starter. Also I have seen recommendations to up battery size when replacing (on cars and trucks). The connections and other stuff ages and you need a bigger battery. A smaller battery may start fine on a warm day when new, but put a year on it and a cold day and it is not as likely to start.

No, it is a batterys plate area that governs its internal resistance characteristic and thereby limits its current output. Voltage dropped across the internal resistance limits the current and thus the tested CCA current rating spec. A 1000CCA batt will always out perform a 950 for several seconds. Any engine that doesnt start in a few seconds has a problem that should be fixed. A starter is not made to crank the engine for a long period. If you have the battery to do it and you do it routinely you will ruin the starter.
Larry

 

[rexcramer]

If you are going to be running the machine in cold weather you will want the extra capacity. Especially if your battery has to fire glow plugs also.

In the south I doubt you will ever need the reserve capacity, because as said above, a diesel that doesnt start in a few seconds has another problem and it needs attention.

 

[BobRip]

No, it is a batterys plate area that governs its internal resistance characteristic and thereby limits its current output. Voltage dropped across the internal resistance limits the current and thus the tested CCA current rating spec. A 1000CCA batt will always out perform a 950 for several seconds. Any engine that doesnt start in a few seconds has a problem that should be fixed. A starter is not made to crank the engine for a long period. If you have the battery to do it and you do it routinely you will ruin the starter.
Larry

I agree with your statement, except I don't understand the "No" in the beginning. Could you explain please?
I think the summary is "Get the big battery". Good discussion though.

 

[Dirthog]

Wished I would have known about the smaller batterys working just as well as a large one think of all the money our dealership and customers could have saved over the last 33 years by using CAR batterys instead of all those big 4D & 8D batterys the mfg put in all dozers, loaders and excavators we have sold all this time