SLA batteris

[ComeOnFish]

One of my Hummingbird FF has been acting up randomly. Wrong depth reading, Fading Screen, blank screen, etc are the random symptoms for the past 3 months. The FF was used over 90 trips and 7-8 hours per trip. Then the same things happened twice on my new Hummingbird FF.
The problems occurred randomly. This time I suspected the one of the batteries.

When I had screen light on, the screen faded out slowly after 50 minutes in use. 2 hours later I disconnect the battery, when I reconnected the battery the FF was find for 2 hours. Then the screen faded out without screen light on. The voltage alarm on FF never went off.

The voltage alarm always went off when the battery was new and I intentionally drained the battery to see how long the battery last.

I have two SLA batteries, 5 ah and 7ah. Both were used 80+ trips, 7-8 hours per trip.
I finally recognize that the problem happened only when I used the 5ah, smaller battery. The 7ah, bigger, and with the bigger terminal (connectors) is still fine.

The voltage reading of the 5ah battery is still 12+. But I think it does not deliver electricity consistently. And now I think it doesn’t get fully charged any more.

The voltage of 8 AA batteries drops when they are aged. So it was not hard to find the AA batteries are bad. But my SLA battery did not drop the voltage. And the problem occurred randomly.

BTW,

The instructions on the 7ah battery stated that the battery must be completely drained three times, so I did that.

But the guy at the battery store when I bought the 5ah battery told me that I should not drain the battery completely. He told me that I should always charge the battery immediately after each fishing trip.

I just received a 5ah battery and a charger from Amazon.com. Both don’t come with any instructions. I am not planning to drain the new 5ah battery. At least I think I can use the 5ah battery for 70 trips – which is a whole lot cheaper than many AA batteries. Though I think I should have ordered a 7ah battery for $3 dollars more.

Joe

[ronaultmtd]

I have a 9 ah Cabela's 12 v battery I bought last spring (on sale for $19.99)- charged it once and fished it all year including two weeks ago at Mattawoman Creek- no problems, whatsoever- I plan to charge it sometime in March for next season's fishing trips- My Eagle Cuda 350 Combo doesn't take much juice to run, so...however, I plan to buy the Hobie bait tank before the striper season kicks off, so that will require me to do more frequent charging...

[Memory Maker]

I have a 9 ah Cabela's 12 v battery I bought last spring (on sale for $19.99)- charged it once and fished it all year including two weeks ago at Mattawoman Creek- no problems, whatsoever- I plan to charge it sometime in March for next season's fishing trips- My Eagle Cuda 350 Combo doesn't take much juice to run, so...however, I plan to buy the Hobie bait tank before the striper season kicks off, so that will require me to do more frequent charging...

Hey Ron ....... the Hobie baitwell comes with it's own battery and charger so you will be charging the baitwell more but not the df battery ........

Hope I read that right

[Southerly]

funny, i was just reading a battery thread,...

the condition of the battery is not judged solely by its voltage. it's more a matter of how well they can hold that voltage under load.

it's probly different test loads than they use for car batts, but your battery vendor may be able to do a load test on your old battery. i've had good results with 'battery warehouse'.

[mmanolis2001]

funny, i was just reading a battery thread,...

the condition of the battery is not judged solely by its voltage. it's more a matter of how well they can hold that voltage under load.

it's probly different test loads than they use for car batts, but your battery vendor may be able to do a load test on your old battery. i've had good results with 'battery warehouse'.

This ^

Bad cells can still read a full 12V but as soon as you place a load on it it will drop. You cold put the voltmeter on the battery with the fish finder hooked up and see if a voltage drop occurs when you power on the unit to test it under load.

[mmanolis2001]

Memory is correct the Hobie live-well comes fully complete with its own battery. I'm not sure what voltage the Hobie live well runs at. It might be a six volt unit.

Running those live-well pumps at 12V will suck a battery dry quick. The live well i made last year is running a small bilge pump at 6V. It ran a solid 12 hrs before it started to die. If i ran that same pump at 12V it would drain the battery in less than 3 hrs.

[Memory Maker]

I think it's a 12 volt engine drawing 6 volts butI can't tell ....... nevertheless, the battery is 6 volts and from what I've seen it works well ......... 12 volts world be too strong for tank so small anyway ...... it's supposed to last a min of 10 hrs ......

[surfdog]

i had to replace my 7ah bat. last year it wouldnt hold a charge any more, replaced it with a 10ah from battery warehouse. i always try to drain the battery to 9 volts so it does not get a charging "memory". i wonder if a 18v drill battery will hold up to the ff load.

[ronaultmtd]

They tell me not to drain a 12 volt completely down...recharge before completely discharged or you can significantly damage the battery.

[daddyg]

Its a fact a battery can read 12v but with a bad cell it might not last 10 min. I have 3 left for MKF $10.00 I have 6v Power Sonic there made for Emergency lighting. I just but a wrap of duck tape around them and a jumper wire 6 + 6 = 12 I used it 9 time without charging it never got below 11v.... I have 3 left 1-7amp & 2- 4.5amp but Ican get more...

[surfdog]

yeah dont drain them to 0v i recharge at about 9v. i was going to put 2 6v bats in series but it was just too bulky for me but will work fine

[john from md]

Folks,

Here are some battery facts and tips.

Deep cycle batteries should never be used below 50% charge. The reason for this is that the plates sulfate and this shortens the battery life. Lead acid batteries of any type do not like to sit as they slowly discharge and the plates become sulfated. If you only charge your battery a couple of times a year, you aren't doing it any favors.

BTW, there is no memory effect with lead acid batteries. Memory effect is related to Ni Cad batteries which are a little too expensive to use on fish finders.

I have both starting and deep cycle batteries on my boat and deep cycle batteries on my aux sump pump at the house. I always keep my batteries on a 500 ma top charge whenever I am not using them. I usually get six to seven years out of them by doing this.

You can buy a small charger at Harbor Freight for about $10 that will keep the battery up when not in use. This is similar to the one that Cabela's includes with it's 9AH battery package. The voltage draw is minimal so it won't add too much to your electric bill.

Granted, small lead acid batteries are not that expensive but, today, every dollar counts!

Regards,

John

[ComeOnFish]

Folks,

Here are some battery facts and tips.

Deep cycle batteries should never be used below 50% charge. The reason for this is that the plates sulfate and this shortens the battery life. Lead acid batteries of any type do not like to sit as they slowly discharge and the plates become sulfated. If you only charge your battery a couple of times a year, you aren't doing it any favors.

BTW, there is no memory effect with lead acid batteries. Memory effect is related to Ni Cad batteries which are a little too expensive to use on fish finders.

I have both starting and deep cycle batteries on my boat and deep cycle batteries on my aux sump pump at the house. I always keep my batteries on a 500 ma top charge whenever I am not using them. I usually get six to seven years out of them by doing this.

You can buy a small charger at Harbor Freight for about $10 that will keep the battery up when not in use. This is similar to the one that Cabela's includes with it's 9AH battery package. The voltage draw is minimal so it won't add too much to your electric bill.

Granted, small lead acid batteries are not that expensive but, today, every dollar counts!

Regards,

John

The guy at the store told me when I bought the last SLA battery "Keep charging after each use". So I have been charging all the time.

joe