My FF is freaking out *HELP*

If you battery is the Hobbico TorqMaster 12V, 7 A/h model....and your Lowrance unit should consume 0.281A @ 12 V DC, then a fully charged battery should run for 24 hours....I could not find a battery discharge curve.....Voltage change(drop) Vs time(amps consumed) to see how the voltage decayed......so, you should easily get three trips and have some reserve time on the battery.....4 usages w/o recharging is pushing it......you could always measure the battery voltage when your fish finder is acting up to confirm that it is not below 10.5 v DC...that would explain erratic behavior......some of us are more erratic than others!     

If you battery is the Hobbico TorqMaster 12V, 7 A/h model....and your Lowrance unit should consume 0.281A @ 12 V DC, then a fully charged battery should run for 24 hours....I could not find a battery discharge curve.....Voltage change(drop) Vs time(amps consumed) to see how the voltage decayed......so, you should easily get three trips and have some reserve time on the battery.....4 usages w/o recharging is pushing it......you could always measure the battery voltage when your fish finder is acting up to confirm that it is not below 10.5 v DC...that would explain erratic behavior......some of us are more erratic than others!     

Actually I think his particular unit draws more than 280 mA.  The spec sheets were combined for the black and white and the color versions.  I believe he has the color version and it will draw more.  I found some info on the net which suggested 320 mA.

SLA batteries are usually rated for the total current they can provide for 20 hours at a "valid" voltage level.  For instance, a 7Ah SLA, can maintain a constant current of 350 mA for 20 hours.  Higher loads would result in less than proportional time, meanting a 700 mA load (twice 350) would not make it 10 hours (half 20 h ours).

So what does this mean?  In an ideal world, on a new battery, you should get ~20+ of run time.  In reality ... batteries are often over-rated, and for normal users their charging profiles don't keep the batteries in new condition.  Getting 1/2 to 2/3 of the rating doesn't surprise me.

-Allen

Allen, I can confirm your statement - I get about 2/3 - 3/4 of the theoretical battery life on my rig, and it's fairly new.  Humminbird 385ci draws 425 mA, so 7 Amp hr SLA should drive it for 16.5 hours..  I get a low battery warning and black screen in 10 to 12 hours..which means I need to charge it every outing or buy a reserve battery if I want to fish a couple days in a row.

I was wondering if you guys that are using the lithium ion batteries have the same results?

A reserve battery is nice to have. I use my 9ah as my main and have a 7 as a spare. Another plus is it is nice to have a back up in a group. If someone is having troubles just swapping a battery often fixes it.

Sent from my Galaxy Nexus using Tapatalk 2

Also keep in mind that the specs you see in the user guides are marketing specs.  They are crafted to look good.  It is common to have disclaimers to them, like "backlight off".  It's also rare to see GPS on/off numbers, so you don't always know what you're getting.

-Allen

I think that the smaller batteries that are rated for say 7A/hour as the unit Paul has are over rated as Allen indicated.....I use a 9A/H Fisher-Price "Barbie car" SLA battery...it weighs about 10 pounds and I can say this thing has been bullet proof and has not failed to work after 20 hours driving my Humminbird 768 combo unit....since my FF has a battery voltage display feature, I monitor the voltage and know when to recharge it.
Smaller/lighter weight SLA's seem to be over rated in real life usage.

Thanks for the battery info gents. Sounds like I need to pick up a higher voltage battery and keep this one as a reserve. I was worried my FF was the problem but it's looking more and more I just needed a solid battery charge.
Paul


Sent from my iPhone using Tapatalk

You should be charging your SLA's after every use.  Heavy discharge and storing in discharged state will shorten the effective life of your SLA.

-Allen

How old is your SLA battery and do you remember where you purchased it from.    Was it from a source who cycles through inventory fairly quickly or possibly one where that battery sat on the shelf for a year or two?

Paul, hit me up when you get home. I can lend you a spare

How old is your SLA battery and do you remember where you purchased it from.    Was it from a source who cycles through inventory fairly quickly or possibly one where that battery sat on the shelf for a year or two?

Got it on amazon. From a hobby store owner. Battery looked new in package and in good shape. I just need to plan on charging after each use.



Sent from my iPhone using Tapatalk

Paul, hit me up when you get home. I can lend you a spare

Thanks Noah. If it still acts up I'll give you a call.
My Canada trip is just wrapping up. Can't wait to get home and start hunting some salmon.


Sent from my iPhone using Tapatalk

Are you catching some fish up there? When are you back?

Are you catching some fish up there? When are you back?

We did really well on coho. Only a handful of kings.
I'm back late tomorrow. Bonneville dam reports show fish are definitely there.