Different sized rear batteries..

[mrdavebasshead75]

Is it ok to run different sized batteries in the rear? For example, if I had (1) Shuriken BT-100 and (1) Shuriken BT-20, can you use them together as in pos to pos and neg to neg? Or does it HAVE to be the same size? Just asking because I got the little guy just laying around and dont wanna sell it.

[HHR Ed]

Different sizes are OK as long as they are the same brand and type battery. Ideally they should be the same size but different sizes will still work.

The main issue is that when they are of different types, one may have a slightly higher resting voltage than the other. Even if this is a few milivolts, the higher batt will charge the lower batt, when that drops down then it will feed back off of the lower batt. And this happens over and over and over and the plates heat up and cause the batts to wear down prematurely.

[getlocivic]

no your fine

doesnt matter on the ah size

example most cars cant fit a 100ah battery under hood so they may go with a 50 or 60ah battery.. its the SAME thing as having them in back

i have my 3100 under my hood and the 3400 and d975 in the trunk

its not a good idea to mix wetcell and agm

[SnowDrifter]

Different sizes are OK as long as they are the same brand and type battery. Ideally they should be the same size but different sizes will still work.

The main issue is that when they are of different types, one may have a slightly higher resting voltage than the other. Even if this is a few milivolts, the higher batt will charge the lower batt, when that drops down then it will feed back off of the lower batt. And this happens over and over and over and the plates heat up and cause the batts to wear down prematurely.

While you have a very valid point, IMHO if you have all brand new batteries, this doesn't really happen.

[mrdavebasshead75]

Thanks guys and getlow, I just noticed u had that d975. Appreciate the help.

[mrdavebasshead75]

Yeah im DEFINITELY not goin to mix wet and dry! But I see what you guys mean now. Wasnt for sure if I could mix the sizes though of the same brand of battery.

[HHR Ed]

Different sizes are OK as long as they are the same brand and type battery. Ideally they should be the same size but different sizes will still work.

The main issue is that when they are of different types, one may have a slightly higher resting voltage than the other. Even if this is a few milivolts, the higher batt will charge the lower batt, when that drops down then it will feed back off of the lower batt. And this happens over and over and over and the plates heat up and cause the batts to wear down prematurely.

While you have a very valid point, IMHO if you have all brand new batteries, this doesn't really happen.

Not true, Certain AGM batts may rest at 12.8 while certain wet cells may rest at 12.6. Even brand new, fully charged. DONT MIX TYPES

[poorfish88]

Different sizes are OK as long as they are the same brand and type battery. Ideally they should be the same size but different sizes will still work.

The main issue is that when they are of different types, one may have a slightly higher resting voltage than the other. Even if this is a few milivolts, the higher batt will charge the lower batt, when that drops down then it will feed back off of the lower batt. And this happens over and over and over and the plates heat up and cause the batts to wear down prematurely.

While you have a very valid point, IMHO if you have all brand new batteries, this doesn't really happen.

Not true, Certain AGM batts may rest at 12.8 while certain wet cells may rest at 12.6. Even brand new, fully charged. DONT MIX TYPES

X2

[SnowDrifter]

Different sizes are OK as long as they are the same brand and type battery. Ideally they should be the same size but different sizes will still work.

The main issue is that when they are of different types, one may have a slightly higher resting voltage than the other. Even if this is a few milivolts, the higher batt will charge the lower batt, when that drops down then it will feed back off of the lower batt. And this happens over and over and over and the plates heat up and cause the batts to wear down prematurely.

While you have a very valid point, IMHO if you have all brand new batteries, this doesn't really happen.

Not true, Certain AGM batts may rest at 12.8 while certain wet cells may rest at 12.6. Even brand new, fully charged. DONT MIX TYPES

I have AGM batteries in the back that rest at 13-13.1, and my front flooded battery rests at 12.8.

I can turn off the car, come back 2 days later and everything is still sitting at 13-13.1. So whatever parasitic draw caused by the front battery is negligible in my case.

[HHR Ed]

Different sizes are OK as long as they are the same brand and type battery. Ideally they should be the same size but different sizes will still work.

The main issue is that when they are of different types, one may have a slightly higher resting voltage than the other. Even if this is a few milivolts, the higher batt will charge the lower batt, when that drops down then it will feed back off of the lower batt. And this happens over and over and over and the plates heat up and cause the batts to wear down prematurely.

While you have a very valid point, IMHO if you have all brand new batteries, this doesn't really happen.

Not true, Certain AGM batts may rest at 12.8 while certain wet cells may rest at 12.6. Even brand new, fully charged. DONT MIX TYPES

I have AGM batteries in the back that rest at 13-13.1, and my front flooded battery rests at 12.8.

I can turn off the car, come back 2 days later and everything is still sitting at 13-13.1. So whatever parasitic draw caused by the front battery is negligible in my case.

The life of your batteries are being cut down