Running three depth finders/battery power?

[walleyehunter26]

I run three Hds 8s two in back one for sonar and one for map and one up front for my partner to see sonar should I be ok for battery power on my ranger 620t it is all rigged on my one starting battery or what is the best option here
?
Thanks

[yarcraft91]

Check the HDS manual, but IIRC, the HDS units draw no more than 1 amp each in normal use and use a 3 amp fuse. Consider the worst case- the HDS draws slightly less than 3 amps.

Assume 3 HDS units, each drawing 3 amps for 8 hours = 72 amp-hours. Your starting battery is probably a 105-140 amp-hour battery, so it would be 50%-70% discharged under these conditions. That should be OK for starting some motors, a problem for a Verado or other voltage-sensitive OB. Upgrade to a group 27 battery, like the Interstate SRM-27B and you'll have an amp-hour rating of 180- plenty of reserve. Routinely 50-70% discharging a battery meant only for starting use will greatly shorten battery lifetime.

Given the HDS units should only draw 1 amp each, you should not have a problem running them for hours on any starting battery in good condition, but you'd be well-advised to choose a dual-purpose deep cycle/starting battery for longer lifetime in such use. Hence my Interstate SRM-series battery recommendation, as that's what I use in service similar to yours.

[Jerryv]

Originally Posted by yarcraft91

Assume 3 HDS units, each drawing 3 amps for 8 hours = 72 amp-hours. Your starting battery is probably a 105-140 amp-hour battery, so it would be 50%-70% discharged under these conditions. That should be OK for starting some motors, a problem for a Verado or other voltage-sensitive OB. Upgrade to a group 27 battery, like the Interstate SRM-27B and you'll have an amp-hour rating of 180- plenty of reserve. Routinely 50-70% discharging a battery meant only for starting use will greatly shorten battery lifetime.

I think you are mixing amp-hour and reserve capacity ratings which is exactly what battery marketing people want you to do! (bigger is better so if you can come up with a bigger number your sales go up)

An SRM-27B has a reserve capacity rating of 180 minutes which means it will supply 25 amps for 180 minutes. That is only 75 amp-hrs. At 5 amps it will go 20.4 hrs or 102 amp-hrs.

http://www.interstatebatteries.com/c...o/marine_f.asp

If you only have one battery in the boat, carry a good jump box because sooner or later you will need it. I would add a "house" battery to run all the accessories and use the starting battery strictly for running the big motor.

Jerry

[walleyehunter26]

I have three batteries two optimas for trolling moors and then my starting battery is hooked to motor and three sonars and boat electronics(live wells, navigation lights, etc.) I was just curious what my best option is now that I run three Hds 8's basiclly at all times

[LWinches]

I have two batteries (24v) for the trolling motor. Then I have two hooked in parallel for starting and electronics. I'm running HDS10, HDS8, HDS5x, Vexilar Edge3, Hbird 7483d with no problems. I do carry a cheap set of jumper cables in case of emergency. My recommendation would be to get the second starting battery and hook it in parallel with your current one for worry free fishing trips. Mostly I just use the cheap walmart Everstart batteries.

[1860Angler]

What size Staring battery to you have now? Go with a good group 31 battery and you will be good to go.

[yarcraft91]

Originally Posted by Jerryv

I think you are mixing amp-hour and reserve capacity ratings which is exactly what battery marketing people want you to do! (bigger is better so if you can come up with a bigger number your sales go up)

Sure enough! My mistake.

[Jerryv]

Originally Posted by walleyehunter26

I have three batteries two optimas for trolling moors and then my starting battery is hooked to motor and three sonars and boat electronics(live wells, navigation lights, etc.) I was just curious what my best option is now that I run three Hds 8's basiclly at all times

In that case skip the jump box and stow a set of jumper cables that will reach between the trolling motor battery and the starting battery. If you don't have them you will surely need them some day. BTDT.

Jerry

[itsagr8day4fishing]

I ran into something similiar. I only run two Hds's but in the spring making long drifts jigging the river running the Hds's and the livewell and only making quick runs back I starting setting off voltage alarms on the units. Boat only came with a size 24 starting battery and all the house stuff connected as well. I was going to just buy a larger battery but wanted the safety net of having two. Ended up just buying another 24 but a deep cell and adding a Blue Sea systems add-a-battery switch with Automatic Charging Relay. House on one Main on the other. They automatically combine when charging and separate if one gets to low. Gives you the option to combine them if need be as well. It has worked out well.

[hiwayman]

I have the same setup as Lwinches for batteries. Works very well for me. Newer Merc. motors need a lot of starting juice. Having the 2nd battery in parallel is great. Run all the boat electrics plus electronics all day with no problems. I have cheap jumpers in the boat, but after this setup I`ve never needed them!