Shoul I switch to Dual Purpose/Hybrid Batteries?

ardeprint

ardeprint

Member
Nov 1, 2010
688
Miami, Florida
Boat Info
2003 Formular 40PC and a 185 SRX 2002
Engines
T Yanmar 440's with V-Drives / 4.3 Mercruiser with Alpha I
I currently have a bank of batteries that is giving me problems. This bank is running two Group 27, MCA 1000, and 182 Reserve. This bank starts my Starboard engine and are my house batts.

Today I was recomended to go with Dual Purpose batts. I did notice that Duals on a Group 27 only have MCA 750, and 175 reserve.

1- Should I go with Duals?
2- If I do, should I go to a group 31 set to match closer to the 1000 MCA's?​
 
ardeprint said:
I currently have a bank of batteries that is giving me problems. This bank is running two Group 27, MCA 1000, and 182 Reserve. This bank starts my Starboard engine and are my house batts.

Today I was recomended to go with Dual Purpose batts. I did notice that Duals on a Group 27 only have MCA 750, and 175 reserve.

1- Should I go with Duals?
2- If I do, should I go to a group 31 set to match closer to the 1000 MCA's?
​
Click to expand...

Go with Optima Blue Top's in the group 31 size. The are the best most worry free batteries made. MM
 
I would go with one starting battery and 2 golf cart batteries for the house. That's what I did 3 years ago, I start off #2 on the MBSS which is the golf cart batteries. I use the starting battery for my generator and can switch the MBSS to #1 to start the boat if the GC batteries are low. I went with Interstate batteries they weigh 63lbs a piece and give me 225 amp hours, you can only use 1/2 of any battery amp ratings which for me when anchored out is 18 between charges.

Ken
 
If my current Cranking bats are rated at CCA 1000 and go with Duals at CCA 750 will this cause problems to start my 350 MPI's?
 
Another dumb question. If duals are incorporating the benefits of Deep Cycle bats, why are the RC #'s lower. Even Deep Cycle bats have a lower RC number. Shouldn't it be the opposite?
 
MonacoMike said:
What is the difference in these batteries besides color of the case? MM
Click to expand...

The blue ones have the additional stud posts - the others do not. Makes it easier to directly connect the charger, etc but of course there are other options.

My guy at Interstate (where I bought my Optimas) claimed that the blue-top cases are more rugged - I have not independantly verified that.
 
I ask again...

Another dumb question. If duals are incorporating the benefits of Deep Cycle bats, why are the RC #'s lower. Even Deep Cycle bats have a lower RC number. Shouldn't it be the opposite?
 
ardeprint said:
I ask again...

Another dumb question. If duals are incorporating the benefits of Deep Cycle bats, why are the RC #'s lower. Even Deep Cycle bats have a lower RC number. Shouldn't it be the opposite?
Click to expand...


Look at the links above, the yellow and blue are the same spec. MM
 
i replaced my batteries with "hybrid" batteries. not impressed. went back to deep cycle... For the boating we do, on the hook radio playing all day, hybrids just weren't the correct choice...
 
MonacoMike said:
Look at the links above, the yellow and blue are the same spec. MM
Click to expand...

I am not reffering solely to the Optimas. I talking in general. Cranking (starting) bats on paper have longer RC (Reserve Capacity) numbers. I would suppose that a deep cycle or a hybrid would have a longer Reserve Capacity.

For example:

Interstate Cranking bat group 27 have 182 RC $110
Optimas Hybrid group 27 have +/- 150 $210
Optimas Hybrid group 31 have +/- 210 $260
 
ardeprint said:
I am not reffering solely to the Optimas. I talking in general. Cranking (starting) bats on paper have longer RC (Reserve Capacity) numbers. I would suppose that a deep cycle or a hybrid would have a longer Reserve Capacity.

For example:

Interstate Cranking bat group 27 have 182 RC $110
Optimas Hybrid group 27 have +/- 150 $210
Optimas Hybrid group 31 have +/- 210 $260
Click to expand...

This link may answer some of your questions, but this part was interesting:

Why amp-hours are specified at a particular rate:

Because of something called the Peukert Effect. The Peukert value is directly related to the internal resistance of the battery. The higher the internal resistance, the higher the losses while charging and discharging, especially at higher currents. This means that the faster a battery is used (discharged), the LOWER the AH capacity. Conversely, if it is drained slower, the AH capacity is higher. This is important because some manufacturers and vendors have chosen to rate their batteries at the 100 hour rate - which makes them look a lot better than they really are. Here are some typical battery capacities from the manufacturers data sheets:

Reminds me of stereo mfg's that rated their unit at 100 watts because it could produce 100 watts at a particular frequency rather than at most frequencies as top line mfg's do. MM

http://www.windsun.com/Batteries/Battery_FAQ.htm#Amp-Hour Capacity
 
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