'BOAT' needs your help and advice

[BOAT]

I don't know what battery monitor to get to monitor my batteries! I need some help and advice on what I should use to monitor the batteries in 'boat'.

Any suggestions?

[kadet]

Depends on what you want to monitor, but I use these for my solar and will be using another for my dc to dc charger;



And my new Yamaha is going to have a Lowrance LMF-400 gauge that monitors alternator and battery voltages.

Blue Sea probably makes some of the best stuff but lots of $$$$ I can get 11 watt meters for the cost of just one Blue Sea monitor.

Just google watt meter your choices will be endless

[BOAT]

I guess state of charge is a controversy - I get a lot of people calling me a dummy because I look at a monitor that tells me the voltage or something and they say that is a dummy thing.

I think maybe I don't know enough to know what I want.

They say a good meter will tell the percentage of battery power that is left in the battery.

Is that what yours does?

[kadet]

Voltage is only an indicator and yes a bad indicator of state of charge.

If you use two watt meters one to measure output and one to message input in watt hours or amp hours you can get a better idea of your useage and state of charge but not necessarily much better.

E.G. if I start out with a fully charged 100AH battery and draw 50AH during a 24hr period and the solar puts back in 25Ah during the same period then you will have 75Ah as state of charge left in the battery or 75% but this is really only an indication as well because batteries are normally rated only on a 20hour usage at no more than a 10% load. So if I used that 50AH on a heavy load of 50amps for an hour my 100AH 20 hour battery really is only a 80AH battery and I only put back 25 so it down to 68%.

Then there is surface charge resistance and temperature to consider. Not to mention battery chemistry and type.

Clear as mud, sorry but nothing is easy with batteries, for most users the at rest battery voltage is as good as an indicator as any. Unless you intend to spend weeks on your boat living off the batteries.

[kadet]

This may do a better job than me explaining it after a quick google

http://batteryuniversity.com/learn/arti ... _of_charge

[BOAT]

E.G. if I start out with a fully charged 100AH battery and draw 50AH during a 24hr period and the solar puts back in 25Ah during the same period then you will have 75Ah as state of charge left in the battery or 75% but this is really only an indication as well because batteries are normally rated only on a 20hour usage at no more than a 10% load. So if I used that 50AH on a heavy load of 50amps for an hour my 100AH 20 hour battery really is only a 80AH battery and I only put back 25 so it down to 68%.

See! This is what I'm talkin' about! I have no clue what you just said! What country are you in? Is that English your speaking? I am just a dumb Yank so please try to take that into consideration.

They have these fancy BALMER things that cost 300 dollars and they claim to be the best way to monitor - but the output on the front just looks like a voltage to me! (Am I stupid? How is this better? )

[BOAT]

This may do a better job than me explaining it after a quick google

http://batteryuniversity.com/learn/arti ... _of_charge

Oh no, that's MUCH worse, I think I like your explanation better - at least yours had less words. The one in the link has many PARAGRAPHS with PICTURES and TABLE and GRAPHS and SCIENCE and STUFF that I will not understand.

Here is the top rated thing at AMAZON for monitoring the voltage - you said I could use voltage?

Is this a good thing?



Here is the link to the item - I picked it because it's waterproof in case I capsize the boat it will still work:

https://www.amazon.com/GEREE-Waterproof ... M9KX74T3QC

(This is harder than I thought )

[kadet]

The smart gauge for $300 is not that much different to what you already have, except the smart gauge will try and learn and adjust for temperature etc. to give a more accurate reading.

But again your display says 100% 100% of what? If your battery is old or has been drained at what temperature what load?

Sorry BOAT it is complicated so just use your meter but don't trust it Or get a Smartguage and after 6 months of useage it will give a better accuracy

From their website:

Accuracy
SmartgaugeTM is proven in independent testing by Enersys® to be accurate within 3% after 6 months of use. SmartgaugeTM automatically adjusts for temperature conditions and the battery’s health.

[BOAT]

I don't have a meter Kadet, and it's not your fault I am stupid, so no need to be sorry. Your explanation was the easiest for me I got at least 11 percent of what you said - I did not get -1% of what that article said and the internet says stuff that confuses me.

I will keep looking around for something - I guess I am getting the impression from what you said that the voltage can be an indicator of what's left in the battery but that as the battery ages or heats up that value will change. So you can't really depend on it? (I think I was better off when i did not understand anything about this, now my brain is hurting).

And the way you are doing it is to measure AMP HOURS? That is totally don't understand.

Thanks for the help.

)(Are you in Australia, ? Isn't it bed time over there? )

[kadet]

No mid morning just about to go finish preparing my boat for it's new motor
Don't let it worry you your AP setup is why better than mine

[kmclemore]

I use a Xantrex Link 20, but I can't say I'm terribly pleased with it. I think it draws a fair bit of current just to run it, and given I'm on a 40W solar panel when I'm out, I can't afford to lose much. Anyway, here's what I have:



I don't think they make it anymore, though Xantrex does have a whole line of monitors. Perhaps the newer ones have lower current draw?

[Herschel]

Boat, I will share what I use for what it is worth. I don't anchor out overnight; when on a trip I tie up at marinas and use shore power to recharge batteries as needed. I do however, keep my boat in a slip full time WITHOUT shore power. I rely on getting underway every three weeks and running my engine for about 30 minutes to keep my batteries charged. I have Optima Blue Tops, one starting and one dual use. They are four years old and going strong. I use this little jobber to keep a general idea of the state of my batteries. It plugs into a "cigarette lighter" type plug. When it goes "yellow" and the numbers start to go down toward 12.5 ish, I know to get the engine on line or plug into shore power for my charger to go to work. I think I paid about $15-20 for it. Meets my needs.

[Highlander]

Well I just installed 2 new golf batts under the aft entry ladder as house batts , moved my new start batt to the port side aft seat beside the ladder my third battery bank for my anchor winch also doubles as a second house batt, all on independant systems if need b or all connected which ever I want , got three 40 watt solar panels to install yet too , but I also got one of these on sale it,ll boost a 6 ltre diesel 40 times weighs 5# compared to my old booster pack #18
http://www.canadiantire.ca/en/pdp/noco- ... p.html#srp

So I figure I got all the bases covered

J

[BOAT]

Yeah John, I do have one of those portable jumper deals and it's a good idea too - I have the cigarette lighter deal in the van and it has let me down many times - the coach battery has failed and been replaced twice - but that's not as important because the van always will start up on the engine battery - but on the boat - if you lose the battery there is no back up so I thought a meter would be nice. I saw the Xantrex stations too.

I think Herschel sort of made the point that diligence is the key here. I guess i will not be able to rely on a meter.

[kadet]

but on the boat - if you lose the battery there is no back up so I thought a meter would be nice

But you do BOAT one of the things I liked about the E-tec before it shat itself was that you can rope start them But a jump pack is easier

Also a battery monitor is not going to tell you if the battery is going to suffer an internal short or lose a cell or two and die just that the volts are OK at that point in time.