Deep Cycle

[spun311]

I've got a deep cycle battery in my boat to start a 55hp Evinrude. I believe it is rated around 600 or 700 CCA. I am trying to diagnose why it might have failed to start after being out on the lake for a little bit. Should it be replaced with a normal starting battery? Or is the deep cycle ok? Thanks.

 

[wilde1j]

Re: Deep Cycle

Deep cycle is better suited for elec trolling motors, etc., than starting loads, but still shouldn't have failed. What elec loads were on it and is the motor charging properly?

 

[spun311]

Re: Deep Cycle

I was listening to the radio for maybe an hour and had my fish finder on for about 3. I am not sure if the motor is charging properly or not. I just got the boat this weekend so I am still finding things out as I go along. I had the battery on a charger at 2 amps overnight and when I left for work this morning its was only reading a 25% charge so maybe the battery is shot?

When it left me stranded on the lake it sounded like it was cranking fine but maybe just didn't have enough power for the ignition system as well?

 

[tashasdaddy]

Re: Deep Cycle

2 amps is a trickle, not enough. get a starting battery just for the motor, then the deep cycle for everything else.

90% of starter problems are bad connections. remove and clean both ends of the battery cables, so that they are shiney, also the cable from the solenoid to starter. check for nicks in the cables. and make sure the connectors are on the wire good. the cable tend to corrode from the inside out, if nicked, corroded wires, and connections, heat up and cause resistance to the follow of electricity, thus the starter doesn't get enough. you can also take jumper cable pos battery post to large post on starter. with a good connection, the engine should spin. then if the starter is good clean everything and retest. then trouble shoot solenoid. starters can be rebuit at a starter/alternator shop, much cheaper than a new one.

i love mine like this, http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=12B8EFRENVPC5MAPNJ3D

also have the battery load tested at the auto parts store, free, i've had new batteries go bad

 

[Vic.S]

Re: Deep Cycle

A true deep cycle battery is not really suitable for engine starting being designed to deliver a much smaller current than starter motor loads, to do so continuously rather than just for the few seconds that engine starting requires and to also withstand many more discharge cycles to a lower level than a starter battery will tolerate without shortening its life.

If purely for engine starting an engine starting battery is the best choice. A high capacity battery is not required, so weight and space can be saved especially by fitting one of the more highly specialised starter batteries.

The fact that the battery in question is rated at 600 or 700CCA suggests that it is probably not a true deep discharge battery but more likely to be a Leisure type which is a compromise and usually more akin to a starter battery. They do vary, though, some being more suitable for engine starting than others.

The one thing to remember with any lead acid battery is that it must not be left in even a partially discharged state for longer than can be avoided. Sulfation and a dramatically reduced service life will be the result of failing to recharge a battery promptly after use.

Batteries other than true deep cycle batteries should not be discharged frequently below about 60% of fully charged and preferably not even that low.

 

[spun311]

Re: Deep Cycle

Thanks for the insight guys.

I took the battery to get load tested after letting it charge for about 24 hours. The load test came back good. I put the battery back in the boat and it fired right up. I let it run for a few minutes and shut it off. About 10 minutes later I was able to start it back up with no problems.

I am trying to replicate the condition it suffered out on the water over the weekend. I drove it for about 30 minutes to my fishing spot at about half throttle as it would not plane out at full throttle. I shut it down when I got to my spot and didn't attempt to start it until about 3 hours later when I was ready to go back to shore. This is when I was unable to get it started. It cranked over fine but just would not fire up. It seems to me that it had adequate time to cool off so I do not think it is a problem of heat soak to the ignition system.

Any ideas?

 

[Lion hunter]

Re: Deep Cycle

I'm with Vic. It may look like a deep cycle but they are not rated for CCA. Deep cycles are rated for amp hours. If it doesn't say amp hours its not a deep cycle. If it says marine it's likely a hybrid. They do ok as a deep cycle but you wont get as many amp hours or recharge cycles out of them.

 

[tashasdaddy]

Re: Deep Cycle

no not heat soaked ignition. it takes a fully charged battery to spin those motors, they have to spin +- 300 rpms for them to start. that is why you use a starting battery, and a house battery for accessories. also keep and emergency start rope on your boat, those motors can be rope started.

 

[spun311]

Re: Deep Cycle

The battery I have is one of those hybrids you guys are talking about. It is rated in CCA as well as amp hours. I think my starting problem out on the lake the other day was completely unrelated to the ignition or charging system. I'm thinking it was a short circuit between the drivers seat and the key........

 

[Lion hunter]

Re: Deep Cycle

I would do as TD said and get a real deep cycle as well to run all accessories and use the other battery for starting only.