When do you charge your electric motor?

[the gecko]

A mate said he gets about two 4hr sessions out of his leccy. I find that about right, but if Ive had a big day, then I wonder whether my leccy needs recharging? should I put a multi meter over it? Am I measuring volts or amps?

Setup is minnkota rt54, second battery is 110a deep cycle, charger is 3 stage 10,000. I also run a relay switch that lets the engine charge the second battery when the main reaches full, while under way.

Now that Ive got a good battery and good charger, I dont want to overcharge it all. What does everybody else do? Just charge it after each session, or go for 2 sessions?

cheers
Andrew

[Poseidon]

In the past I would only ever charge the battery overnight prior to each session. I have a fairly good quality 4 stage charger which would turn a drained battery around quite well.

Just recently I have decided to leave the charger connected to the battery between sessions as the unit has a maintenance feature that regulates the output from the charger to suit battery status. From researching a little on this it would seem that the constant maintenance provides the battery with a better charge.

I think it really all depends on the type of charger that you have as to what is best practice.

Here is a photo of the charger I use.

Regards Cameron.

[the gecko]

I use a projecta charger, its this model;
http://cgi.ebay.com.au/PROJECTA-AUTOMATIC-12V-15A-10000mA-BATTERY-CHARGER_W0QQitemZ190176426812QQihZ009QQcategoryZ30 862QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I guess what Im really asking is how do I tell how much power is left before I charge?

cheers
Andrew

[Poseidon]

If you really wanted to know the charge left you could use a Hydrometer to measure the Specific Gravity of the cell. Measuring volts across the terminals won't tell you if the battery is charged, a flat battery can still return you a normal voltage reading. Or you could just assume the battery is low and charge anyway.

The charger you have will regulate output dependant upon the battery status, no damage is done if you place the charger onto a fully charged battery nor conversely if the battery is very discharged.

[Didley]

Hi Gecko

I got this battery gauge from Bass Pro (US) a few years ago it works well.U can also get an in dash version of it.16286

[oldboot]

With all lead acid type batteries they prefer shallow charge cycles so the best time to charge a battery of this type is after each use.

there is no advantage to allowing it to cycle deeper.

If you have an even half decent multi stage charger you can not over charge the battery.

you can establish the state of charge of a battery by measuring voltage, but the battery must be at rest, unloaded and you need an accuate voltmeter.

the whole charge range runs from 10volts stone dead flat to 15 volts fully charged and still on a fast charger.
All the sensible readings will be between 12 and 14 volts...... so we are talknig fractions of a volt.

realy what you need to know is....... charge with a decent charger at the earliest oportunity.

And yess i would agree that leaving the battery on a good modern charger will be better for the battery all round..... especilay if it may be weeks between uses at times.

cheers

[Swamp]

Just before it stops is good

Jokin

I think experience is the best judge

[artesian]

stuff I have read says that discharging a battery too low will shorten it's life, maybe dramatically, but what is 'too low' depends on the type of battery.

A search here will reveal some (divergent) views.

[Melec]

g`day mate .your minkota will have a spec sheet that tells you how much current it consumes . example it may use 10 amps per hour, your battery is a 110 amp hour , you have 40 amps available out of that ,.before you should recharge . new school of thought is only use a max of 40% of batt capacity . so without putting a monitoring device on your batt you have approx 4 hours use before recharge . c-tek is an exellent charger tha0zt canbe put on your batts at anytime for anytime .

[oldboot]

let me clarify what I said before.
No lead acid or related battery or benifits from deep cycles, however some related technologises based on lead acid will tolerate deep cycles better than others.
So you are always better of recharging at first oportunity.

Do not be confused with other completly unrelated battery types which are not used in general boating applications. some of these do like deep discharge.

cheers

[plaztix]

Always charge as soon as possible after use.

I have a ctek which is designed to be left on and will maintain a battery at its optimum level of charge but usually just top up every week or so. I don't like the idea of having something on in the shed constantly (other than the beer fridge)

[1337]

Charge immediately after use as leaving batteries flat is not good practise.

Get a multimeter and measure voltage -12.7v across the terminals is a good indicator of a fully charged up battery.

Refer to this link for additional info mate - hope that helps
http://www.trojan-battery.com/Tech-Support/BatteryMaintenance/Testing.aspx

Regards
CT

[the gecko]

Thanks guys. Im gonna get a meter and measure it. I know charge early, charge often, is good practice. My concern is that the boat is outdoors and rain could get in the charger. I usually just put a bucket over the charger, but I prefer to charge less if Ive had a short fishing session. Last night I only used the minn kota for a total of 30 min in a 6 hr session, so I will get another session before I recharge. Im just one of those guys who likes to measure everything.

Appreciate the feedback.

Andrew

[artesian]

G'day Andrew,

I shelter my charger from the rain when charging outdoors as well - dunno whether your model gets hot or not, but mine does, and I don't know that a bucket would suit my charger.