Thread: Mixing Batteries Sizes

Originally Posted by DonDon

Keep in mind the 27's are only 2 or 3 months old so they are new guys

Don.....they will still pull the 31 down because they are smaller. I learned this the hard way years ago working with big diesel trucks....they have three group 31's on most of them and if we mixed sizes or put a new battery in with a older one we always paid for it later so we got to where if one battery was weak or bad......we replaced all three with 31's. This proved to save us money in the long run. A group 27 is way to small a battery to be using anyway especially with as big a TM as you have. What your wanting to do will work for a little while.....it won't work good but it will for a little while and in the end your new 31 will be bad as well and then that money will be wasted.....If you can put three new 31's on now it will save you a lot of grief and money.

Originally Posted by "G"

Don.....they will still pull the 31 down because they are smaller. I learned this the hard way years ago working with big diesel trucks....they have three group 31's on most of them and if we mixed sizes or put a new battery in with a older one we always paid for it later so we got to where if one battery was weak or bad......we replaced all three with 31's. This proved to save us money in the long run. A group 27 is way to small a battery to be using anyway especially with as big a TM as you have. What your wanting to do will work for a little while.....it won't work good but it will for a little while and in the end your new 31 will be bad as well and then that money will be wasted.....If you can put three new 31's on now it will save you a lot of grief and money.

Don, now that EVERYBODY has told you this, you're not going to be hard-headed, are you??