# Batteries for Dummies



## nathanielrthomas (Feb 7, 2011)

So I just bought a new battery. Its a Everstart Maxx Marine 29 series. It replaced my old 27 series Duralast that left me stranded a few weeks ago.

My question is this:

What is the difference between a 27 and a 29 series battery? Would a 31 series have been a better choice?

Thanks guys


----------



## russ010 (Feb 7, 2011)

Reserve Amp Hours... that is what you are looking for when buying a battery... the higher the reserve amp rating, the longer run time


----------



## nathanielrthomas (Feb 7, 2011)

russ010 said:


> Reserve Amp Hours... that is what you are looking for when buying a battery... the higher the reserve amp rating, the longer run time



Is that the same thing as Reserve Capacity?


----------



## russ010 (Feb 7, 2011)

No they are not the same.... If all you see is Reserve Amp Capacity, divide that by 2 - that will generally give you a rough ballpark of the Reserve Amp Hours

check out some of these FAQs - https://www.dcbattery.com/faq.html#3


----------



## rweathers1 (Feb 7, 2011)

Just a guess but I think the series number is the size of the battery. the bigger the number the bigger the battery (dimensions). Could be wrong but that is what I'm thinking the diff. is


----------



## russ010 (Feb 8, 2011)

rweathers1 said:


> Just a guess but I think the series number is the size of the battery. the bigger the number the bigger the battery (dimensions). Could be wrong but that is what I'm thinking the diff. is



the higher the series, the more reserve amp hours the batteries have. 

I had the series 31 Everstart Maxx in my boat for about 4 years... and I had to replace them every two, but I fish all the time and I just wore them out.


----------



## grasshopper (Feb 8, 2011)

i see a lot of guys on here asking about batteries so here is some info. that might help., 
group U1 = 34 to 40 amp. hours 
'' 24 = 70 to 85 " "
" 27 = 85 to 105 " "
" 31 = 95 to 125 " "
"  4D = 180 to 215 " "
" 8D = 225 to 255 " "
also you can run two batteries together one way is to get more amp. it is called parallel you run neg. to neg. and pos. to pos. so you have 12V 100 amp hour and 12V 120amp hour you will get 12V 220 amp hour if you run parallel 
the othe way is called series you run pos. to neg. if you have two 6V 100amp hour batteries you well get 12V 100 amp hour if you run series. 
I hope this helps some of yall .


----------



## screwballl (Feb 12, 2011)

Look at the CCA or MCA rating, and divide that by 20 for your Amp hour (Ah) rating. This will be more useful for trolling motors. You can have a 1100CCA battery at 55Ah that may only be a 24 series, just as you can have a 31 series at 800CCA that would only give 40Ah. Series generally just refers to weight of the battery.and heavier batteries have a longer overall life, regardless of their CCA/Ah ratings.

Example:
My battery has 825 CCA, which comes out to approx. 41 Ah. Since most trolling is done low speed, at 5A low speed draw, that is 8+ hours.

Mine is a MK Endura 36 with Max draw 34A, so if I ran mine at the highest speed with lots of wind and water and weed resistance, I would get 60-90 minutes out of it.


----------

