What's the best battery charge tester, reasonably priced?

CCC

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Viajero

Well, any cheap VOM meter will tell you what your battery voltage is. But that is not really a test of the battery. 

If you are looking at load testing it then just grab whatever load tester is on sale at Canadian Tire or whatever the American equivalent is as far as an auto parts store. These are typically under 50 bucks, have a big coil inside that heats up and two very large battery clamps. Watch a you tube video on how to use them and have at it. The battery may appear fine with a volt meter but completely fail under a load test. 

Heads up. Don’t freak if it smells like something is burning the first time it’s used. It is. But it’s no big deal. It’s just what happens. 

Cheers. 

Sharon_is_SAM

If you mean a monitor, this will get you started.  Boy has it gone up in price!  

qhumberd

I have read on the forum many times it is a right of passage to ruin your first battery. That got my attention so I decided that a battery shunt would provide all the data I might need on the performance of a battery. Victron makes a good shunt device that is commonly used but expensive.  I got the AiLi shunt for less than 50 dollars and installed to monitor both flow into and out of our battery. It monitors voltage very accurately so you can judge battery heath when it is under load. Really helps with anxiety about how much you can discharge the battery without causing damage. Several threads on here provide info on installing shunts.

pthomas745

A multimeter is my favorite tool in my tool box.  If you can learn how to properly "measure the voltage of a rested battery" with one of these, every other step up the battery monitor level will make even more sense. There are simple tools like a multimeter that attach directly to a battery and can send you the battery voltage via bluetooth, also. 

And, it is a great tool for many other small electrical issues, also.

(I have a Victron shunt, too, but I love my meter!)

Marceline

I used an earlier version of this device (https://amzn.to/3MOwVmO)

for a year or so, but if you plan to do a lot of boondocking it would probably be better to just bite the bullet and get a Victron SmartShunt (https://amzn.to/3KDbROV). 

SLJ

Quicky if you If you have a voltmeter but don't have a battery tester, measure the battery voltage at full charge with it off shore power or solar charging. Then turn everything on you can and measure it again and watch it for a few minutes. If the battery continues to drop in voltage while you watch it you know you have a problem. If you boondock a lot don't add anything to monitor it like a SmartShunt that's a constant drain. Solar controllers are also a drain when there's no sun. I put mine on switches so they're off when I'm not using them and know there's no sun for a long time. There are a lot of parasitic drains on the T@B battery.

ScottG

If the battery is a common wet cell, another approach to assessing its health is to monitor the gravity of the electrolyte in each cell using a hydrometer or refractometer. This can also tell you if one cell is going bad--a common point of failure.

Last season I retired my aging but still functional six-year-old battery to spare status. I had previously noticed one of the cells tested a little low. Although I never needed to use the battery, by season's end I noticed it would no longer hold a charge, and--sure enough--that one cell was totally shot.

pthomas745

The solar controllers and shunt "drains" are incredibly small.  The manuals state the smart shunt uses "less than 1 milliamp."

SLJ

pthomas745 said:

The solar controllers and shunt "drains" are incredibly small.  The manuals state the smart shunt uses "less than 1 milliamp."

While shunts and controllers are relativity low, Bluetooth increases the draw. Granted by themselves they won't do much but if a T@B is sitting unused or being stored over the winter it adds up combined with everything else that is a constant draw. The point is combined with everything else it will all eventually draw a battery down to the point of no return if left to sit out of the sun.

B11

@pthomas745, @SLJ...Is it possible to have a Victron shunt and or a controller and avoid the drains @SLJ is referring to while the camper is stored over winter? I haven't stored over winter yet, and I'm only guessing, but wouldn't the battery shutoff be applied in the case of storing the camper? Or, as with other smaller battery operated items I've had, simply remove the batteries from the unit over winter then reinstalled when ready for use to stop the constant drain.

VictoriaP

@B11 The shunt and solar controller are usually installed before the battery cutoff switch, so using that wouldn’t help with any drain. That said, I don’t have onboard solar, do have a SmartShunt, and I have a smaller AGM battery capacity than your 400. It’s a total non issue. Battery drain from the SmartShunt with the battery switch turned to off is negligible. I installed the shunt in the middle of winter. Zero change in battery charge between January and April. None. It’ll overwinter just fine.

Sharon_is_SAM

Even without installed solar, just fully charge your battery prior to storage, make sure your inverter is turned off, turn off the battery switch and you are good to go.  We have a 150 Ah AGM without solar and store it with the battery switch turned off.  We come back after 6 months and it has never been any lower than 12.8V or 99%.

Denny16

You can turn off the solar charging/controller from the Victron phone App.  That said, ours remains on all winter, ant it along with the Victron Shunt do not drain the battery, the solar panels get enough sun (even though they are facing North) to keep the battery charged, even with the battery switch on.
 Cheers 

Parlando

@pthomas745 and anyone else with Victron Smartshunt experience. Have you found that the bluetooth is strong enough to get a reading inside of the T@B. Or is buying the $50 dongle necessary?  Thanks

VictoriaP

@Parlando I have no trouble taking readings from inside a 2019 320 with the older Boondock tub. There’s been at least one report of someone having an issue with the newer tub, which doesn’t have the open back of the older model. We never established whether the tub, shunt, or the phone used was at issue. So my suggestion would be to skip the dongle for now, or buy it from somewhere that makes returns easy, and try it out for yourself. 

Marceline

Parlando said:

@pthomas745 and anyone else with Victron Smartshunt experience. Have you found that the bluetooth is strong enough to get a reading inside of the T@B. Or is buying the $50 dongle necessary?  Thanks

I have been able to connect with mine from both the tow vehicle and from inside my trailer.

pthomas745

I have no problem inside or in the vehicle with the signal.  My trailer is outside in the drive about 25 feet away, and I can connect from here.  Doesn't work through the wall, though, I need to see it out the window.

Parlando

@VictoriaP @Marceline @pthomas745 Thank you all for your responses.  Will any of you be at the East meets West gathering. We are coming.

Horigan

FYI.  I found this inexpensive non-Bluetooth battery monitor shunt that gets high praise from Will Prowse.  Plan to put this on our boat.

https://www.amazon.com/AiLi-Voltmeter-Ammeter-Voltage-Motorhome/dp/B07FGFFHC6/ref=sr_1_9?keywords=battery+monitor+12v+with+shunt&qid=1652454077&sprefix=battery+monitor%2Caps%2C220&sr=8-9

Marceline

Parlando said:

@VictoriaP @Marceline @pthomas745 Thank you all for your responses.  Will any of you be at the East meets West gathering. We are coming.

Sorry, no. I went a few years ago when I was in WA to see family, but I haven't been that far north lately. Maybe next year...

dsfdogs

@Parlando Are you looking for a Multimeter? I have this one from Harbor Freight and it's cheap! In fact, it might have been free with a coupon. I found a video on YouTube to learn how to use it. I really only use it if I want to take a reading directly from my battery. I do not have a Victron smart shunt.
https://www.harborfreight.com/electrical/electrician-s-tools/multimeters-testers/7-function-digital-multimeter-63759.html
I will be at the rally.

Parlando

dsfdogs  Thanks for the suggestion. I do have a multimeter, and have been learning how to monitor the battery with it.  Mostly I want to monitor the battery usage inside and often in the cold and dark. So I'm considering the victron to monitor from inside the T@B.  I do appreciate saving costs, as you'll see from my awning at East Meets West.  Looking forward to meeting you, and thanks.

Parlando

Horigan