amp meter?

[id10t]

Finally got my canoe set up to enjoy the local rivers and gulf coast in style - electric trolling motor et al

Unfortunately my paranoia about running out of go juice is always in
my head - sure my buddy and I can paddle a few miles but ....

So I need a "gas gauge" (and a second battery at some point)

My motor has a useless one - impossible to see in the sun and even then it is "full", "eh halfsies" and "get ready to paddle"

I want something a little more granular (so I can plan on the 1/3 rule left over from my cave diving days) and more importantly visible

Dont need fancy console mounting etc - just something I can put inline when I hook up my motor etc

Suggestions?

[Cajundaddy]

Here you go. This is a bluetooth shunt that sends current, voltage, and state of charge to your smartphone. It is indispensable when on battery power and you want to avoid getting stranded.

https://www.amazon.com/Victron-SmartShunt-500AMP-Bluetooth-Battery/dp/B0DJ2P2XN5/ref=pd_lpo_d_sccl_1/132-7929347-2908650?pd_rd_w=3zIik&content-id=amzn1.sym.4c8c52db-06f8-4e42-8e56-912796f2ea6c&pf_rd_p=4c8c52db-06f8-4e42-8e56-912796f2ea6c&pf_rd_r=PVKGSHH8N6CHYPEEDD22&pd_rd_wg=05Dzx&pd_rd_r=4631964f-d385-41f5-a0d9-20c511465464&pd_rd_i=B0856PHNLX&th=1

[id10t]

Originally Posted by Cajundaddy

Here you go. This is a bluetooth shunt that sends current, voltage, and state of charge to your smartphone. It is indispensable when on battery power and you want to avoid getting stranded.

https://www.amazon.com/Victron-SmartShunt-500AMP-Bluetooth-Battery/dp/B0DJ2P2XN5/ref=pd_lpo_d_sccl_1/132-7929347-2908650?pd_rd_w=3zIik&content-id=amzn1.sym.4c8c52db-06f8-4e42-8e56-912796f2ea6c&pf_rd_p=4c8c52db-06f8-4e42-8e56-912796f2ea6c&pf_rd_r=PVKGSHH8N6CHYPEEDD22&pd_rd_wg=05Dzx&pd_rd_r=4631964f-d385-41f5-a0d9-20c511465464&pd_rd_i=B0856PHNLX&th=1

Phone has less battery life than the trolling motor, and I don't use non-Free software if there is a choice. Looking for analog/dial or LED bar style (have seen both on the golf carts around campus)

[908/930]

I think you just need a voltmeter, and to keep track of run time after certain voltage.

[911 Rod]

How about something like this? You charge your phone too.

[dad911]

^^^ I have that on my boat.

I also use a battery analyzer every few months to check the batteries.

[juanbenae]

Is there a cut off voltage for the motor? Is the system 12V? If a good 12V battery is charged you should have near 14V with no draw or charger attached. I'd be interested in at what voltage would the motor no longer operate at. Say 10V? 8V? That'd be a good thing to know if you are going to be testing voltage when the Minow is in use.

[juanbenae]

I'm not electrical guy, frustrates the hell out of my pops as an electrical engineer. One thing he told me that has stuck in my mind is comparing volt v. amps is a water comparison. Volts are like a charged waterline PSI, whereas amps are like when the facet is turned on the delivery rate.

[908/930]

If it is a lead acid or AGM battery you really want to avoid bringing the battery voltage down too low, probably below 11v is low and the battery lifespan can suffer.

[911 Rod]

Cheap trolling motors use a lot more juice that good ones.

[Cajundaddy]

Originally Posted by id10t

Phone has less battery life than the trolling motor, and I don't use non-Free software if there is a choice. Looking for analog/dial or LED bar style (have seen both on the golf carts around campus)

I can't speak for your phone battery as mine lasts 8 hrs and also connects with USB for unlimited power.

If you need a physical gauge instead of free phone app, this Chinese one works. These genuine shunt monitors give you precise battery state of charge while a volt meter only offers a rough approximation.

https://a.co/d/7BRiEx9

[id10t]

Originally Posted by Cajundaddy

I can't speak for your phone battery as mine lasts 8 hrs and also connects with USB for unlimited power.

If you need a physical gauge instead of free phone app, this Chinese one works. These genuine shunt monitors give you precise battery state of charge while a volt meter only offers a rough approximation.

https://a.co/d/7BRiEx9

Ordered a very similar one should be here tomorrow and Im hittin the water again Sunday

Knew about voltage != charge state until it gets to be too late in my use case

Once I get a trailer (car topping means totally emptying it) I plan on adding some stuff that will extend life (use a pwm for speed control vs using in line resistors to slow motor when not running full on) but then also some things that will draw more power (nav lights so I can run at night, fish finder etc)

[id10t]

Got out on water yesterday, the "gas gauge" worked great and seems to be accurate when the battery is under load, much more precise than the one built in to motor