Opinions on Costco's Deep Cell / Starter Battery

[Stu Jackson]

Questionable battery chargers

I've assumed that since both chargers indicate "full" prior to sailing, that they have done their job.

You're welcome. Skipper, the "giveaway" was that the batteries were gassing off the acid. That should tell you something (not too good) about your charger. Glad we could help.

 

[Stu Jackson]

Combo deep cycle/start batteries

I was in Costco's Tire store and noticed that they have a Deep Cell / Starter combination battery for about half he price of WM's.

WM Advisor's have changed their tune on these puppies. They used to kinda "downgrade" 'em, saying they were more for powerboaters who used one battery for two purposes: starting their "hefty" engine and listening to blaring music with 2,000 watt deep bass boom boxes!

Now they've changed to recommend them, probably to sell more stuff.

If you have a good house bank with deep cycles, and a separate reserve bank which can be as cost effective as a simple car battery from Sears at a REAL good LOW price, you shouldn't EVER have to deal with combo batteries (unless you have a very small boat with room for only one, in which case I'd recommend a deep cycle anyway). Maine Sail and I and others have discussed using the house bank for starting and using the reserve bank as a truly reserve bank.

You've also answered your own question about cost effective sources for batteries. A little comparative shopping can go a LONG way. You know now, next time, eh? :cry:

 

[caguy]

You've also answered your own question about cost effective sources for batteries. A little comparative shopping can go a LONG way. You know now, next time, eh? :cry:

Trust me I know from comparative shopping. The purchase a WM was purely for convenience sake. It killed me to buy it there. I had purchased my prior Deep Cell from Costco's about 3 yrs earlier. We were in a hurry to get out on the water and WM is across the street from the launch. The reason I commented originally on the combo set is that the DC I bought from Costco's before was a 90 amp. This combo is 115 amp. I also understand that the plates in starter batteries are made thinner. What I was questioning is if its a combo is there a compromise in the thickness of the plates and thus a shorter life span. Also being 115 amps should theoretically give me 25 amp hours longer charge for those 4 day trips to Catalina.
If you want to know the real heartbreak... the next week my new battery was also dead. That was until I cleaned the crud off from the main fuse. Chances are the old battery that Timo42 and I left on the dock was still good. I didn't expect it to be there when we got back from sailing but if it had I would have thrown in in the back of my truck. One of the wharf rats probably scrapped it.

 

[Stu Jackson]

Dual Purpose Batteries - back

I also understand that the plates in starter batteries are made thinner. What I was questioning is if its a combo is there a compromise in the thickness of the plates and thus a shorter life span. Also being 115 amps should theoretically give me 25 amp hours longer charge for those 4 day trips to Catalina.

One of the wharf rats probably scrapped it.

Frank,

WM Advisors say this about dual purpose batteries. I disagrre conceptually with their second suggestion about dual house/start banks. MS convinced me that what we'd been doing for years is just fine using the house bank to start the engine. And two equal house banks is way-old system design and reduces the life of the individual banks compared to one larger bank with the same exact amount of individual batteries, as discussed many times here and elsewhere.

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Dual-Purpose Batteries: We generally advise that you choose either a deep cycle or starting battery for best performance and battery life, but dual-purpose batteries work well in some applications. With large thick plates containing more antimony than starting batteries and an active lead paste chemistry, dual-purpose batteries are a good compromise, tolerating deep discharges that would ruin a typical starting battery. Since they have lower storage capacity than comparably sized deep cycles, we recommend them for the following applications:

[*]Runabouts or other small powerboats using a single battery for both starting and running loads with the engine turned off.

[*]Sailboats with two identical batteries used interchangeably for starting and house electrical loads

[*]Boats with one battery bank that does double duty for house applications and engine starting. Dual-purpose batteries will last longer and give more reliable service than a starting battery, for about $20 more per battery.

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Sorry about the battery an your return to the dock. Remember the thread last week about "recycling your boating goods?" I use the area around the dumpster for my "reusable" things, or ask this particular guy down the dock who needs all the help he can get with that kinda stuff (stereos, binoculars which have been replaced but still work (daytime only!), you know the kinda stuff)!

Have fun,

Stu

 

[Rich Stidger]

well.... there is the desulfanator type products that might do some good.....

has anyone had any good luck trying to bring back a dead battery?...

--jerry

Well, Jerry, I haven't brought back a dead battery but I have had success in improving the performance of batteries that were abused.

In 2007 I inadvertently chronically undercharged my house bank of 450Ah. After the season's end I did an equalization charge. Not being satisfied that the equalization "fixed" everything, I built my own "nano-pulsing" circuit and tailored it to the size of my house bank.

I applied this circuit to my house bank for two months over last winter and took measurements along the way.

My measurement of interest was the internal resistance of the batteries. I have four 6V deep cycle units made by US Battery. Over the two month test period I measured a 13% average decrease of internal resistance in the batteries. The actual values were 5.78 milli-ohm at the start and 5.08 milli-ohm at the finish. This would correspond to the batteries being able to supply more current at a given terminal voltage.

I have an Excel spreadsheet with all the data if you or anyone is interested.