battery cranking amps

[g32004]

What is the difference in a starting battery of a car or a boat if the cranking amps are the same.

This is my problem I have a marine battery that is 660 cranking amps on my boat. Every time I trim up my Gps goes off for a second then comes back on.
I think I need a bigger amp battery. A car battery 1050 cranking amps is alot cheaper than a Marine battery. I think you can buy the terminal.

Can I do this?

 

[Silvertip]

Re: battery cranking amps

An automotive battery is not designed to take the pounding a marine starting batteries is designed for. Otherwise your correct -- an AMP is an AMP. Most modern electronics are protected against voltage surges, overvoltage, and undervoltage. Your GPS apparently senses a momentary under voltage condition when you trim up because the trim system takes more power in the up direction than down direction (gravity helps going down). How old is the starting battery? It may not be able to hold a charge and when the relatively high demand of the trim system occurs, the voltage drops too far. Check battery cables and clean them (both ends). As an experiment, try your 1050 car battery. You can also put a voltmeter on the GPS leads (it may even have a battery voltage display) and then operate the trim to see what voltage drops to when you trim up. Check the specs in your GPS manual. They normally list operating voltage limits.

 

[ZmOz]

Re: battery cranking amps

A car battery will do you just fine. They may not be "designed" for a boat, but neither are the cheaper "marine" batteries. Some higher end marine batteries have thicker plates to resist all the vibrations...but cars and trucks aren't exactly vibration free either. My boat has a 9 year old store brand car battery...still works fine, and my inline 6 requires more starting amps than a V8.

 

[Texasmark]

Re: battery cranking amps

The problem may not be the battery at all. If it is operating properly the battery you mentioned should be more than adequate for your needs.

The wiring to the electronics may be such that there is a series connection rather than parallel. Series would mean that when the line voltage drops under the trim change load, the electronics senses it. It could be the power line to the dash or the return.

A simple fix which would not require rewiring would be to put a capacitor across the power and ground wires to your electronics. This capacitor would charge up to line voltage upon power initialization and during short periods of interruption the energy stored in the capacitor would supply the electronics and they would be impervious to the glitch.

A 100 microfarad electrolytic rated 50 or more DCWV from Radio shack should do the trick, mounted right across the power/ground wires as close to the electronics as possible. + on the Cap has to go to the +12v power line and you might want to secure it with a clamp or some RTV so that the leads don't break because of wave pounding, etc.

Mark