deep cycle battery's

[yipster]

many deep cycle battery's are getting close to the same price of regular car battery's i noted
hear they can be used to regular start from also so should i go for deep cycle batts and whats there to look for?

[gonzo]

A deep cycle battery has lower cranking amps but more amps/hr. If it is rated for the amperage you need to start, it will work fine. However, it will be much larger in size than a cranking battery.

[Willallison]

Are you going to use it as a house battery as well as for starting?

[SheetWise]

Here's a great link with a lot of free information that they continue to update and add to. http://www.windsun.com/Batteries/Bat...of%20Batteries.

[yipster]

thanks for the reply's guy's and it seems to make sence for me
i'll check the shops specs on deep cycle hybrids

[Willallison]

the reason I asked what you wanted to use the battery for is because it makes little sense to use a deep-cycle - or indeed a 'hybrid' - if all you are going to use it for is to start the engine. And vica-versa.
I imagine this is for your Searay..?
In which case you probably have 2 batteries, with the opportunity to switch between them. One for house and one for starting. I would have thought that the ideal senario would be to have a dedicated start battery, plus a deep cycle with relatively high cca (cold cranking amps) thiat is also capable of starting the engine in an emergency.

[takasden]

If you have two batteries, there should be an option to parallel them for emergency starting should your "start" battery be low. The requirements for starting a big diesel vs a gasoline engine also vary and may have different battery requirements.

[Willallison]

Assuming Yipsters Searay is set up the same way my slightly newer one was, there is the ability to do this - Off / 1 / 2 / Both.

[yipster]

88 sundancer 27 it still is Will. gas engines with Off / 1 / 2 / Both switch in bilge plus emergy SB / BB starter switch on dash, had things a bit rewired tho as in drawing.
looking on the net for new batts i noticed deep cycle battery's now similar priced as regular and had a camping gell batt before i liked.
someone said there good for starting also so i trew it in the forum.
probably have the marina put regulars in but how much sponge / lead is that

[marshmat]

I'd go for the deep cycle if you can handle the extra bulk and weight. Since you still need the same or greater cranking amperage, the deep cycle will be a lot heavier than the cranking-only battery. But the deep will also last a lot longer. With twin batteries it is often nice to have them of the same size and type, so that you can use either battery for all your needs.

[Mikey]

My experience is that deep-cycle last almost twice as long as normal batteries, that's worth a lot.
Mikey

[Ike]

I think we are forgetting that starting batteries and deep cycle batteries are constructed differently, and using a deep cycle battery for starting all the time is really not good for it. Using it once in a while or in an emergency is OK but constant use at high amperage rates can shorten it's life, resulting in warped plates and overheating. A hybrid is a good choice if you have only one battery to serve both as starting and house battery but if you have two batteries, one for starting and one for house, it's better to use a starting battery.

The main difference between these batteries is the construction. Starting batteries have thin plates with lots of plate area for generating high amperages for short periods. Just what a starter needs. Deep cycle have much thicker and heavier plates to release energy at a much slower rate for long periods of time, at a much lower amperage. Trying to push a deep cycle to produce the kind of current a start needs can eventually result in damage to the plates. As I said , occasional use or in an emergency is ok.

[Willallison]

I would concurr with Ike 100%.
It's also remembering that regardless of what battery type you use, if you don't look after them, they will fail prematurely. I can sight the example of my parents 48 footer. The previous owner had spent a great deal on a bank of expensive German gel-cell battery's. He had then operated the boat with them all connected together and with the charger incorrectly programmed, so they were continually being cooked. 12 months old when we bought the boat and we had to throw them away.....

[yipster]

wise words Will, forgot to mention i still have that 3 stage charger, getting help from discount store's so far is another nono, battery's, where is trouty

[FAST FRED]

"and using a deep cycle battery for starting all the time is really not good for it. "

Nonsense , the start cycle is quite short and stops when the plates are fully covered with gas , if someone cranks too long.

This does NO damage , long or short term to a deep cycle batt.

The problem is will the deep cycles have enough plate surface area to crank the diesel for cold (0F) starts ?

It takes a bunch of deep cycle batts to have the plate area as a starting batt set , but IF the set is large enough , it works just fine.Dieselsa need to spin rapidly to generate the combustion heat , and that takes plate area, for low voltage drop.

A good 3 or 4 stage charger (usually an alternator with special voltage regulator) will restore the bat set in as short a time as can be done. A temp probe is REQUIRED if the alt is over 25% of the batts 20hr rating.

Charging from a gen set (unless over 15KW) with a smart charger is usually slow as the tiny gen sets dont make the powerfull wave form that dock power does. Figure 75% of the chargers amp output rating.

FAST FRED