What group battery for my trolling needs...

[FishNotWork]

Hi everybody -

We're buying a 16' Smokercraft aluminum fishing boat later today (if everything checks out right). I'd like to buy a bow-mounted trolling motor for it like this MinnKota Powerdrive V2 65(65 Lbs. Thrust). It's a 24V motor so I will need two 12V batteries in series to run it.

My question is what group battery should I buy for my needs: Group 27, 29, 31 or 34?. I've read some posts on computing the available minutes from the information on the battery but I don't know how much current the motor will draw, so I'm not sure how to estimate the draw range.

I'd like to use the main motor for moving from place to place and then use the trolling motor once we get to a certain spot. I like to troll with it too from time to time.

I've seen Group 29HM batteries at Sears for $124.00 - they are rated at 115mins at 20A (so about 2 hrs). Does this mean that two of them would allow me to troll for approx. 4hrs without running out of juice?

 

[Silvertip]

Re: What group battery for my trolling needs...

That is not a good battery deal. I just bought a group 27 at my local farm store for $69 and it has much higher reserve capacity (175 minutes at 23 amp draw). No -- two batteries in series does not double run time. Two batteries in parallel doubles run time but still provides only 12 volts. Your motor will draw 40 amps max. You do not need anything larger than a group 27 in my view but that depends on how you troo, how long you troll, how fast you troll and under what wind, water and current conditions. With 175 reserve minutes, running at max current those two batteries will last roughly 1.5 hours. However, that numer can basically be doubled since you rarely run at max cuurent continuously. Start stop operation at much lower settings is the norm. I also question the need for the 65# motor when the 55# (12 volt) is adequate for that boat. My alumacraft 17 footer performs great with a 55 and only one battery to weigh you down. If there is room for two batteries then those in parallel would double the run time.

 

[Scott Danforth]

Re: What group battery for my trolling needs...

sears has the same batteries as many other places for about 50% more, I suggest you shop arround.

I recommend the group 31's over the 27's as they will fit in the same bracket, and offer a higher ah rating. the reserve capacity in minutes is calculated at 20 amp draw and is a standard method of rating batteries.

 

[mark1905]

Re: What group battery for my trolling needs...

My policy with a boat is to always buy the biggest and best battery that I possibly can. You can never have too much electrical reserve capacity IMHO.

I've been running Walmart marine deep cycles for years with no problems.. and they're around $75 for the biggest they have. Do some checking.. almost all batteries come from the same factories but with different badges on them. Johnson Controls makes the Walmart brand, Autozone batteries, Costco batteries, Interstate batteries, etc etc.

 

[FishNotWork]

Re: What group battery for my trolling needs...

I also question the need for the 65# motor when the 55# (12 volt) is adequate for that boat...

Slightly off the original topic but following up on the above I found a 55lb motor locally - but it has a 52'' shaft - it seems like a really long one, though I think it's adjustable.... is there such a thing as too long of a shaft? I have a 16 foot deep-V boat..

http://denver.craigslist.org/boa/2933429753.html