Lehman SP135 srarting battery size

[mike66]

My current starter battery is a 4D. It is also connected to my anchor winch and bow thruster, both of which are operated only with the engine running, and never together. Everything operates well with this setup, but I'm looking for a solution I can handle by myself when the 4D dies. Suggestions? Two GC batteries?

 

[gaston]

WOW if your getting away with just 1 X 4D now Id be very tempted to just add another 4D and make it switchable as a back up """KIS""""

PS I have 7 doing the same

 

[psneeld]

I use a group 31 size battery for a Lehman 120.

After a couple calls to American Diesel, I really didn't get a straight answer.

So looking up the starter requirements, even a group 27 would have been more than enough. But I went a little bigger for reserve and a few more cranking amps. $105 at Walmart.

After 5 years, even after not charging for awhile she cranks easily.

By going with a small battery, I put it right next to the starter and all works well.

 

[Larry M]

We have 2 Optima Yellow tops for our SP135. No maintenance, slow discharge rate and weight less than 60 lbs. We bought the last 2 on Amazon with free shipping and no core charge.

 

[Capt.Bill11]

Since it's more than just a starting battery, I'd put in two group 31s.

 

[jleonard]

My starting bank is 2 group 31s.

 

[mike66]

Thanks everyone! Good to know I don't need the heavy artillery.

 

[dhays]

The starting battery part is the easy one. The thruster and windless would take a bit more. If it was me, I'd assume I could start the engine with anything and so would look at what your windlass and thruster manufacturers recommend for those. Anything that will meet those demands will start your engine.

 

[kchace]

I have a single Group 27 for each engine - and they've been quite sufficient. Though next time I may opt for grp 31's just for the extra margin.

Ken

 

[mike66]

Vetus recommends group 31 700 cca, 85ah for the 55 bowthruster; the Lewmar pro 100 windlass is 700 watts, or about 60 amps. My alternator is a 80 amp (approximate ). Looks like I'd be okay with one 31, but I may double that up.
BTW, I think I really need a STARTING battery. How come spell check didn't catch that?

 

[mike66]

Just an update to beat this horse to death. Since my house bank is also 2 4D batteries, and are only two years old, I decided to transfer one of them to the engine start battery position until it dies, then it will be replaced by a smaller one. 2 new GC batteries will go in the house bank, switchable to parallel the 4D if needed. We use very little power on the hook: the fridge, led anchor light, and maybe a few led cabin lights. I'll keep that spare 4D on a trickle charger when not in use. When it goes, I'll replace the whole house bank with GC's. Whole point of this exercise is to make the batteries easier to handle and have a true deep cycle house bank, while using up what I have.

 

[Comodave]

I have 2 4Ds for starting my SP225s. I think they are overkill, but they are easy to get to to replace so I will probably just stick to them when these go bad. That way I won't have to rebuild the battery boxes. I have 4 6V GCs for the house that the PO switched to from 2 8Ds. Thank god he did that since you can barely get the 6V ones in and out. Don't know how they ever got 8Ds in and out.

 

[JDCAVE]

I have a couple of Group 24's that start the engine. The engine starts within 5 seconds even in cold weather. The windlass is also connected to the starter batteries but you really only use the windlass when the engine is running together with the alternator.

When I was still trying to figure out which end was up in the seas of boating, i had switched off the ACR, as I had been advised never to combine the house and start bank. At the time I had thought that the digital duo charge was responsible for charging the start batteries, when in fact the ACR provided that function. After a week of cruising about and using the windlass I had discovered that the starting back was at 50% SOC, and yet the windlass still worked (albeit slower than I though proper) and the engine still started fine. Anyways, I find 2 group 24's work just fine and are more than adequately charged with my current Mastervolt battery isolator.

 

[alormaria]

I have 3 batteries. One held for starting and two in parallel for the house.
I started with Group 31s, went to Group 27s now using Group 29s. It never seemed to make a difference.