Trolling Motor Puzzle

[inshore]

two (2) new batteries a trojan and excide and no help. got a motor guide 70 lbs thrust 1999 model. when i use the motor

only the front battery is pulled down. went today came home checked on handy volt meter front battery 8.85 volts back

battery 12. 35 volts. been happening awhile thought had bad battery. charged down battery then checked plug at the

motor showing 24.2 volts. and yes did check batteries before i left both fully charged. i'm at total loss where the other

12 volts is going. any one out there have any suggestions beside making anchor out of trolling motor?

[Craig]

Sounds like the 8.5 v battery has a bad cell. Test the specific gravity of cells or do load test, or forget all that and take them to a battery store. Battery outfittets works for me. Should use 2 like batteries

[fishinwrench]

Firstly, always replace 24v TM batterys in pairs.

Secondly, "fully charged" only means that the cell has taken all of the charge that it is capable of..... that doesn't mean that the cell is "good", it just means that it will not accept any more amps.

A bad battery will show 100% charged on an automatic charger, because it actually is "fully charged"..... it has reached it's full capacity.

[Bird Watcher]

This may sound like a stupid question, but does your TM have a selector for 12V or 24V on the foot control? I have one on the front panel and one on the foot control and if I bump one to 12v it will only run one battery down.

[fishinwrench]

Bird watcher, if that's true then your boat is wired cheap, your 12v should pull parallel. Do you have only 3 leads running from the stern to the bow, or 4 ?

Switchable 12/24 has never made sense to me, there's no benefit to running 12v when you can run 24v at a lower setting. Never understood the concept or reasoning for that.

[Bird Watcher]

Bird watcher, if that's true then your boat is wired cheap, your 12v should pull parallel. Do you have only 3 leads running from the stern to the bow, or 4 ?

Switchable 12/24 has never made sense to me, there's no benefit to running 12v when you can run 24v at a lower setting. Never understood the concept or reasoning for that.

Yeah, it's really weird. I've never had one like it on other boats in the past. It's two completely seperate sets of leads(4 wires) that both go back to my batteries independent of each other. They don't intersect again until they hit the rocker switch on my front panel. It doesn't look cheaper to me. It's another 18' of 6 gauge wire and another thermal breaker that I didn't have on my last boat. So that's at least another 30-50$ more expensive than the last 24V system I had. I don't know why they did it that way, but it's definitely factory original.

Actually, in the past i felt the same about 12V vs 24V, but I've found that in really shallow clear water, I like to switch to 12V and put my TM on the lowest setting. There is quite a difference between the thrust and noise when compared to the 24V mode on the lowest setting. It really helps me sneak around in the tiny clear water creeks without alarming the fish I'm after.

[fishinwrench]

If you've got four 6ga. going up then it's not cheaply wired.... somebody just didn't configure the wiring/ switches quite right (or it may just be a missing or loose jumper wire at the switch.

If you actually use the 12v option it would be worthwhile to get that straightened out so that your pulling parallel off both batts when on 12.

Most TM upgrades I do are from 13/24 to straight 24, and in that case I terminate the 12/24/chg. switch and run 24v up both sets of cables and either upgrade the plug or hard-wire it straight to the pedal. Keeps the whole circuit nice and cool.

[Martin]

The batteries need to be checked "under load".....My first two pro-guides frpm Battery Outfitters went in the boat, brand new. My trolling motor only turned about 10% of the prop rpm's it should have. I checked the wiring and found no problem.....Checked voltage at TM plug and it read 24 plus (volts)......I called battery outfitters and explained my problem and what steps I had taken. The first thing they said was, "It doesn't matter that your meter shows 24 volts. If it's not checked under load, it means nothing. I took the batteries back as they told me. Had to leave them since THEY have to charge them with THEIR gear and then they'll check the batteries. BOTH brand new batteries had 2 bad cells.....They gave me 2 new batteries, which I lugged home and re-installed into the boat......TM was better, but still not right. I took the whole dang boat to them (so I wouldn't have to wrestle those two big batteries) and they repeated what they had done on the first pair.....Guess what. One of the "new" batteries had a bad cell.....That' my friends, is why I no longer buy pro-guide batteries from B. O........They did replace (again) the bad battery, but they whole fiasco left me more then a little PO'd at those guys.

As somebody previously said, batteries should be replaced in pairs and of the same make and size...

If you get 2 good batteries hooked up, your problems will be over. (unless your TM is shot...lol)

[fishinwrench]

2007 seemed to be a really bad year for batterys of all makes, no idea why or how but I'll never forget how plagued everyone was around here with battery return/pro-rate refunds, it totally burnt me out on dealing batterys. The straw that broke the camels back was when I recieved a "lead acid battery tax" statement from the state saying that I owed over 600.00 when I only realized a profit of less than 500.00 from selling batterys that year.

I buy them as I need them now, somebody else can have that headache.