How to Test your Boat Battery Voltage with a Multimeter!

[@DanRichardFishing]

Just a small tool tip video I shot yesterday while filming this week's video. Having a multimeter is critical when working on the electricals of your boat or car and they're very inexpensive. Next video will be back on our regular schedule, Thursday at 2PM EST!

[@antoninorandazzo378]

😮😮😮😮😮😮😮 3:12

[@Perkykurt]

Thanks for this quick little helper. I appreciate it.

[@andrewwiltzius6228]

just what I was looking for , thanks

[@charliefeinstein943]

Perfect. Exactly what I needed to know. Thanks!

[@cliff-8412]

Great vid Dan! Helped me install my 94sv uhd

[@DanRichardFishing]

Awesome, glad it helped!!

[@Quillmgs14]

Solid! Thanks.

[@octaviofuentes7781]

Thanks for sharing my man

[@chrischorney5085]

Very nice straight forward video thanks man. I’m so sick of Everyone talking about there dog and there wife and their family and every goddamn thing other than what the video is suppose to be about the first 10

[@DanRichardFishing]

HAHA! To be fair, I tend to over-explain in my how-to videos, but I put in chapters so people can skip to the parts they want :) I try to keep my intros to a minute or so :) glad you liked this one, thanks for the comment!

[@chrischorney5085]

It’s a great video buddy!

[@georgemccane5376]

Thank you. Helpful.

[@DanRichardFishing]

You're very welcome! :)

[@scottrenfro1164]

Can you make a video on how to check (using the multimeter) my onboard battery charger? Thanks.

[@DanRichardFishing]

I'll have to check how that can be verified... smart chargers will test to ensure it's connected to a battery before it will even charge so I'll have to do some research on this one. Thanks for the video idea!

[@Theskyisgreen436]

Can you post a video on how to test voltage on a trolling motor

[@DanRichardFishing]

I do have a video coming up on something like this on a trolling motor that doesn't work correctly! I'll be sure to show the voltage check!

[@ltownandfriends4531]

played music in boat today with engine off and was wondering to what voltage can i let my single 102ah deep cycle battery drop until i can no longer start the engine? ive got a 5 liter petrol engine. also got a victron controller that goves me exact voltage reading.

[@DanRichardFishing]

This is a good question but it's also very hard to answer because you can't judge this on battery alone. Voltage doesn't start an engine, amps do so the condition of the battery will determine how effectively it can delivery the amps your engine is drawing to start. So if you have an older battery with ineffective cells, then it will have trouble pushing amps at higher voltage, whereas a brand new battery could have no issues delivering the required amps at 11.5 volts. As a general rule, anything under 12 volts is a drained battery and you risk getting in trouble :)

[@dparel]

Don't you have to disconnect the batteries? I have 2 trolling batteries and 1 cranking/electronics battery. Trolling motor has been acting funky and I'm wondering if my batteries are going bad. It's been 3.5 years with these.

[@DanRichardFishing]

By acting funky, do you mean the trolling motor is dying faster than usual or seems underpowered after a few hours? Easy way to tell is charge them up, and run the TM for a couple hours on the water as usual and then check the voltage on each. No need to disconnect them to do this as you are post to post on each battery. If one battery is much lower than the other, you found your bad battery. If you have a fairly new marine bank charger, it should be signaling if you have a battery not holding a charge either although I wouldn't rely on that 100% Hope that helps!

[@dparel]

@@DanRichardFishing funky meaning doesn’t hold spot lock for 1. Seems to when they are fully charged but after 30-45 on water it won’t spot lock anymore. Last two times (both failed) it was also windy out. Haven’t been able to test in different situations yet.

[@ethanm1580]

Hi Dan, good info there. I have watched your past videos of you troubleshooting your Garmin sonar interference issues. I am about to install a Striker 7 on my boat this spring. I have a Terrova also. I'm not looking forward to this now... :-( Have you found a way to reduce the interference somewhat since that video? (where you mention all the steps you have taken) thanks

[@DanRichardFishing]

Hi Ethan! Thanks so much for watching my videos, really appreciate it! Unfortunately there was nothing I could do about it, the motor housing itself is just pumping that EFI noise and no one could figure it out. It's become a "that's just how it is" situation. I'll be upgrading motors soon so it's not the end of the world. What version of the Terrova did you get? If you have the Bluetooth edition, you have a newer generation than I do so you may not have that problem any more :) Let me know when you get it installed! All the best :)

[@ethanm1580]

Thanks for the reply Dan, much appreciated! The Terrova is an older ( 55 LB,12V). I'm currently running a Garmin Echo 500C and getting those vertical lines also. I am using the internal transducer on the Terrova and connect to the sonar via US2 Adapter Cable / MKR-US2-12. I did not clamp on the Garmin transducer to the motor head. I'll do the same with the Striker 7. How did you run the transducer cable up to your sonar? Does it get tangled a lot? I might sell this Terrova and upgrade sometime.

[@carlosdeno]

Great video thank you 👍🏼

[@dellscatering975]

Great video. Forgive me if I am new to this but I just purchased a used boat and it has three batteries hooked up for various items. There is an external charging system that plugs into the wall that charges all three. How would I test to see that everything is fully charged? Also, I had a weird thing happen yesterday. I got off of the water and then plugged it in to charge and it was like I could hear a faint bubbling sound coming from the 1st battery in the charging system. Is that normal lol? Thanks for any guidance!

[@DanRichardFishing]

Thank you! No worries, please don't be shy to ask your questions, that's why the channel exists :) So actually testing if a battery is fully charged is difficult unless you have specific tools to do this. You can get a general sense of the charge by looking at the voltage... if the battery is lead acid based (not lithium) and is showing 12.7 volts or higher, it's fully charged. If it's showing ~12.4v then you're at ~75% charge. I'd just keep this easy... your battery charger should indicate if your battery is fully charged, so if you plug it in and it keeps charging and never shows 100% charged, you may have a battery issue. You also need to look at the real-world use. So if you charge a battery overnight and the charger is showing fully charged, but it only lasts a few hours out on the water, your battery is likely end of life. If the batteries are older than 5 years old, you should probably change them anyway. Lithium batteries actually have indicators on them that show you the charge and others have connectivity with a phone app to the BMS to check. A faint gurgling sound when charging a flooded lead acid battery is totally normal. The charging process heats up the electrolyte (the acid in the battery) and it can bubble and let off some gas. Nothing to worry about :) Hope that helps!

[@dellscatering975]

@@DanRichardFishing Thank you very much for that explanation. It helped a ton. Keep up the awesome work. Subscribed!

[@SpikedVanlife]

Afaik deep cycle can go down as low as 11.8 and still have 30% charge. And that's float value. Under load can drop to as low as 10.5v with a trolling motor pulling full 40+ amps, but once you let go of the throttle, it could still come back up to 12.2v after a few hours of trolling... which is normal...agm will also have different values than flooded

[@DanRichardFishing]

You shouldn't be draining your VRLA battery that low (30%) on a consistent basis unless it's an AGM. Once you're under 12v, a typical VRLA should stop being used and charged. And yes of course, totally normal a battery will drop under load unless connected to a charging system. All measurements should be done with no load. Thanks for the comment!

[@joehubbard4405]

Thanks for getting to the point 🙏👍

[@evanhoskins4968]

I know this question has alot of different answers but if you could give me a general answer. Im running a battery for my trolling motor on a 10 foot jon boat.. At what voltage should I start looking for a way back to the truck.. In General..

[@DanRichardFishing]

Haha well that depends on how far from the truck you are. Once you start dropping below 12 volts things can get interesting in a hurry. 12.20 is 50% charge, 12.0 is around 25% charged and you're now draining the battery too far. Ideally you don't want to go lower than 12.08v - assuming we are talking about lead acid batteries, not Lithium.

[@evanhoskins4968]

@@DanRichardFishing Im assuming this is when NOT under a load right? My completely charged battery fresh from the charger goto 12.0 - 11.9 under a load.I dont think ive ever seen it below 12.80 not under a load after like 2-3 hours of trolling.

[@dexter7s847]

if i Battery is 36v ,so i go to dc 20 or dc200?

[@DanRichardFishing]

You can use DC200 for that :) Thanks for the question!

[@dexter7s847]

@@DanRichardFishing thank you

[@rbrood267]

Hi. Maybe you can help me. I bought a new semi traxi battery 75 ah and used it for three weeks untill i found out my rectifier wasnt wired up to charge. the voltage dropped down till 10.8 and now i am charging by boat and it would go up till 11.7v Is this battery broken now or should i charge it with a charger?

[@EastCoastCasting]

Quick question for you. I have been trying to find an answer inline but haven't been able to locate much. I was running a group 24 interstate cranking battery that was purchased in April of this year for obviously my 50 HP mercury and 2 echomap 73SVs. Right after taking the battery off the charger, the Garmin units read 11.9 volts but when I hooked my volt meter up the battery read 12.79. Thought maybe something was wrong the the interstate so changed it out for group 24 everstart. Charged that up and checked it on my Garmin units and it read 12.6 and on the volt meter 12.8. I fished for about 2 hours to test it out and the voltage dropped to 12.2. Any idea what could be causing the voltage difference? Even with the low voltage with the interstate I never noticed a picture change and did not get any warnings.

[@DanRichardFishing]

Hi Ryan, the low voltage warning could be set to different voltages, so doublecheck what it's set to on your unit. If it's set to 11v or something like that, it would explain the no warnings. The unit will work down to 9 volts, so you won't see any picture changes or really any issues as long as you're above 9v. As soon as you drop lower, the unit will simply shut off. In terms of your testing of voltage and voltage drops, there's a lot of factors that could affect reading a slight change in voltage on your readings at the battery vs at the unit, but a difference of 1 volt seems odd. What I would do is check the power at the cable itself by testing the female end of the cable and seeing if that matches what the unit is telling you. I wouldn't worry about 12.8 vs 12.6 but 11.9 vs 12.8 seems weird. Things that affect voltage between the battery and the unit are purely connection related, so a poor ground or positive connection would be something to look for, or using wiring that is too small. Also check that the fuse connection is good, no corrosion etc. Btw I am pretty much using the exact same battery as you, a group 24 interstate lol! My marine starting battery died out on my and this was an emergency replacement that so far has been doing a great job :) Hope that helps!

[@EastCoastCasting]

@@DanRichardFishing thanks for the feedback. I have actually checked it at the connection and it was the same as what it was directly at the battery. That is one of the major reasons why I am incredibly confused

[@michaelross5674]

Just bought a brand new 12 v deep cycle marine battery hooked up multi meter and it's going up to 19. Something and shutting off saying 1.

[@lal3724]

So if im using my new 105 amp hours battery on my trolling motor, (only 28lb thrust), can I use my fully charged battery for an hour or two and then see on the volt meter how much charge is left? If it reads 12.7 before launch, would turning around, going the same speed, at say 12.5, get me back? I just want to avoid the battery running out while on the water. it's hard coming from using phones and devices with a battery percentage to marine batteries where it seems you have to look at voltage to measure charge. everything im seeing with the volt meter seems to measure battery life, not battery charge

[@colsoncustoms8994]

I ran around all night on my wide / heavy 16’ Jon boat chasing down jugs with 2 of these www.ruralking.com/catalog/product/view/id/28357 and I’m right at 12.4. Granted they were 13.4 and 13.7 before hitting the water. That was about 6 hours on the water, probably 4.5-5 of it moving around. I try to keep it on the 1,2,3 settings most of the time and only use the 4&5 setting in quick bursts. It’s a 30lb thrust motor and I probably traveled 2-5 miles, or more. Went back and forth on a long / skinny 200 acre lake 4 times and ran around a bunch in between, not sure the miles but I can certainly tell the second battery was there last night (only had one 2 nights ago, it definitely started to loose some steam on the way back, setting 4 was comparable to setting 2 on a fresh battery). Not sure if that’s any help.

[@arthicks4785]

What about 12v LITHIUM batteries. How do you test them for voltage??

[@vtxdaryl]

12 volts are 12 volts, check it same way.

[@arthicks4785]

Thanks. I was thrown a blind curve. I was checking the voltage on a Lithium "Smart" Renogy Batt. which I didn't realize has to be "turned on" from shelf life. It comes in that mode from the factory. It also comes with a plug in switch. Once I turned it "on" it read correctly.

[@vtxdaryl]

@@arthicks4785 Thanks for responding.

[@DanRichardFishing]

Hi Art, as D Carlton mentioned, you test them the exact same way :) Check out my LiLead review video and you can see me testing the voltage on it :)

[@vtxdaryl]

@@DanRichardFishing Thanks for the shout out, great explanation. I had a Multimeter from Harbor Freight, free of course and it was showing 17+ volts. Thanks to your video I bought a new Multimeter and it works. Put the free one where it belongs.

[@ThePackDad]

Why is my RV battery showing zero when I test but can power my RV? Testing other vehicle batteries gets normal results with the same meter.

[@DanRichardFishing]

You're testing right at the battery posts and you're 100% sure you have the right polarity?? That doesn't make any sense unless you have another battery hidden somewhere on your RV LOL

[@colsoncustoms8994]

My new deep cycle batteries sit at 13.7v when fully charged 😅

[@DanRichardFishing]

Is it a lead acid battery and is that the voltage when the motor is running? If so, that makes sense.

[@TheRodFather5913]

Word

[@DanRichardFishing]

up!

[@chris2884]

Just because a battery shows 12.6-12.8 doesn’t mean it’s good.

[@alloftis4684]

Sorry, that’s not a load test

[@DanRichardFishing]

Correct, this is how to test standing voltage.

[@hankjones2975]

@@DanRichardFishing This is not the way. You have to load test it. Tomorrow it may show low voltage.