What are symptoms of LX-7 battery going bad?

[buz23]

I couldn't get the red light to go off this year, even after a couple of days.  Then I started to see a slight flicker on the chart display, after fishing a while.  Finally, yesterday, it suddenly quit showing a return signal, even though the rest of the unit was functioning normally and the Xducer was clicking.

This behavior didn't change when I put the charger on it when I got home, or even when the battery was up to 13+ volts.

Is it possible the battery has enough volts but not enough current output to run the unit properly?  I'm not sure the charger puts out enough current by itself to run the unit.

After corresponding with Marcum, I sent it back for a tuneup.  But maybe I should have rigged it up to a car battery first.  Another possibility is a broken wire in the Xducer, but no damage is visible on the cable and I'm pretty gentle with it.

[Old Goat]

sounds like a bad charger        read up on Marcum chargers people been having problems with them  I hope that will get you up and running again. Try a voltmeter on that battery

[buz23]

I used an external voltmeter on the battery and got around 13.7 volts (but only after an hour or so on the charger, go figure).

[3300]

symptoms of a battery going bad is it's lack of being able to keep voltage and amperage for the normal duration your are used to having with it and a new battery or like it was when it was new. so if you got 8 hours on it and now it 5 or there abouts is the easy way to figure it out it's time for new. amazon has them for 20$

ideally, you want over 12 volts the entire time your using a battery w/o a charger. no load battery voltage (shelf voltage) will be 12.5 volts. charging battery voltage at high will be 13.8 volts (that's the voltage 12 volt appliances prefer).

i use the battery tender jr on all my smaller sla batteries. i had a wire fire from a cheap auto charger like the ones that come with these units, except it has no fuse in line. it could have got ugly fast if i wasn't home.
i knew a safer and better charger was needed then. the battery tender jr hooks directly up to your lx7 and it comes with larger alligator clamps like bigger charges have.
marcum ensures this won't happen with a fuse in line and the battery tender jr also has it's own fuse, so your safer by far.

[buz23]

Thanks 3300, but what happens when the battery runs out?  Does the whole unit die or does it just start to act up???

[DR.SPECKLER]

if the lx7 still acted up when the battery registered 13+ volts on a volt meter.im thinking its not the battery.a bad cell in a battery will charge up voltage wise but fail while under load though.

[3300]

it's called a brown out when you under voltage things. it's bad on them too. medical facilities using line conditioners and ups and generators to ensure they have voltages controlled full time. peoples lives depend on it.

for us, it can cause damage to the device, mostly the processor, but all the other devises controlling voltage can become hurt/weakened because they have their limits designed into them. you won't see any damage, but it could change say the values of tolerance they used to have. as a whole, many components have a 10% value of accuracy. amps/voltage are the fuel for those things and are designed to have the right amount fed to them. we stretch their limits already not having a charger on them while using the battery alone. keeping a fresh battery keeps the amps and voltage it needs, but on the low end of those needs.

if you have that meter handy, turn on your charged battery (a rested recently charged battery) and read it. then watch how fast the voltage drops. if it drops say to 12 volts quickly, then it's toast. it shouldn't drop below 12 volts for hours tho.
it's best to buy new and use your old for lighting. that's what i do.
if you have a heal lamp or some thing that uses more power than your lx7, try that as a load test of sorts.  or turn your back light to max. that's what depletes the battery the fastest with any battery, just like notebook pc's and tablets and phones.

to answer your question, i don't or haven't run mine with a bad battery yet, so i don't know what to look for using the sonar/. that's why i am answering using the battery alone. you should still haveit and can mess with it while waiting or just replace it and have a spare.

marcum says most of the repairs sent in are from users having a weak battery. here's their quot for the lx 7:

Whatever is wrong with your Sonar, when it leaves here it will be as good as the day you bought it. Turnaround time for a Digital Series repair is around 3-5 days. Before going any further, make sure that your problem is not as simple as a weak battery.

[buz23]

Its on the way back.  Bad transducer.  Funny, it just crapped out while I was using it, not after dropping or wrapping line around it.  I wish I had the thing so I could check it out - maybe a wire broke?

[3300]

they are complicated.

dug this up for ya
http://www.davegenz.com/articles-and-news/transducers-key-to-quality.html

will be back for the cold blast!

[buz23]

An update:  the unit arrived back Friday (11 days total).  I opened the package hoping I wouldn't find the screen broken as was reported in the main chit chat thread.  Everything looked OK, the transducer was obviously brand new but the repair sheet also said "replaced electronic component".

I turned the thing on in my dining room and it behaved exactly as it had before I sent it in!  All functions OK, but no return signals.

So now I am wondering - maybe it was the battery after all, so I made a panic trip up the lake to an easy access point with fairly deep water, dragged my auger and the LX-7 out on the ice and gave it a try.  It worked - but looked to be reading much too shallow for what I remembered for that location.  I panicked.  Drilled a few more holes out towards deeper water and was relieved to find it was reading correctly - I had not remembered where the drop was.  I had to reset my settings, somehow they had reverted to factory settings and in my panic to set it up I accidently saved over my preferred setup.

Took it back home and set it up in the dining room again and could not get return signals.  Before it totally crapped out, I would get noise on the return which would at least show something on the chart display - now nothing.  So I am thinking the noise I was seeing before when I thought it was working was actually a symptom of the transducer going bad.

Remember I had not been getting a green light on the battery charger - so I ordered a "Battery Tender Junior" from Amazon.  $10 cheaper than Wallyworld even.

Put the Marcum charger on and left it over night - LO and BEHOLD, this morning a green light.  So now I am totally confused but relieved to have a fully functioning unit again.  Can't wait to fish, with my new FX-100 that I just put together yesterday.  Not this weekend, too cold and going to my in-laws.

[3300]

I turned the thing on in my dining room and it behaved exactly as it had before I sent it in!  All functions OK, but no return signals.

what do you mean by this?

to test it at home, it has to be done over cement or ceramic tile floor. on level 2-4 you should have a red line at 2 feet and 8 feet and an echo/double image at 16 feet.

if they replaced the transducer, they change one resistor too because the traducer burns it out when it goes bad. knowing both are new means no issues from that circuit.

i have a new fx100 too. they upgraded it so it's better than their older one. i sold my older one to a buddy that was like new and 2years old.
i added the reflectex and wind bar and longer rope and led lights to the new one and the hyfax runners.
i noticed a few things different about the versions. the worst part is there seems to be more fabric in the front now and so more of it blows into the fishing space. not good with heaters and lanterns running.
the other is the amount and placement of the front velcro straps. there used to have one strap for each corner of the door on the bottom bar. now theres only one in the center. so it's harder to use the door.

[buz23]

When I had tried it in the dining room previously with the transducer just on a table (before it failed completely) it would chart some noise;  after it failed and when I got it back there was nothing at all on the chart screen.  Wooden floor.

My FX-100 has 3 velcro straps on each corner of the front bar and one in the center.  I did notice that the front wasn't real taut when I got it together, but locking the windbreak bars seems to help tighten things up.

I haven't put the screws into the skirt yet, wondering if I should try to get it tighter.

Do you have any idea what part 10328 (second page of instructions, bottom left) is supposed to be?  I didn't find anything like that in my box, and I can't find any mention of them in the assembly instructions (not too good in my opinion)  but perhaps they are velcroed covers for the windows??

[3300]

marcum says test it on hard surface tho, not wood or carpet.

that part # is the windows already attached, but the #'s are there for you to have a parts list for ordering replacements.

i didn't bother with the black screws this build. it will be easier to remove the tent and put it in a sealed plastic pail to keep mice out.

yup, they added one more tent corner strap, but moved the door strap to the middle instead of one strap per corner of the door itself. not the tent corners. when you look at the door, there was one strap on each corner so when you zip it back up the strap held the fabric in place. now it won't.