Best battery testers according to redditors

A multimeter won't really work, you need a battery load tester like this guy that actually puts some load on the jump battery.

http://www.amazon.com/gp/product/B000EVWDU0/ref=cm_cr_ryp_prd_ttl_sol_17

If you just want voltage, which will give you an idea of battery drain, this is it

I sort of doubt it on a 2014 Honda.

If the battery is more than three years old it's the battery.

You need to measure the charging voltage it should be over 14V when running.

One of these gizmos is handy as it shows the state of the battery charge when the car is off and shows charging voltage with engine running:

https://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0

Note that Honda has a variable output alternator; that can confuse some folks doing voltage testing since it reduces output to around 12.7 volts when battery is charged.

that'd do it; i don't know why you'd need two inverters though.

also you want a deep cycle battery rather than a regular car one as car batteries are designed for short bursts of high energy rather than a sustained drain. deep cycle batteries are used for running the electricity on boats and RVs. make sure to get one that's "100ah" or higher. that's essentially the amount of power available in the battery and the more you have the longer you can power your stuff. you can get two and connect them in parallel (google image this for a diagram) to increase your available energy.

you'll also want to get a battery charge reader so you can monitor how much charge the battery has. a full charged battery is 12.6v, and you should turn everything off and recharge if you dip down to 12v as that's around 50% charge and anything less than that will actually kill your battery and it won't charge again.

definitely don't do the gennie, we have enough air and noise pollution out there...


battery
http://www.amazon.com/Universal-Power-Group-45978-Battery/dp/B0044Z8DJW/ref=sr_1_1?ie=UTF8&qid=1374787029&sr=8-1&keywords=UPG+UB121000

combine these two items to create a battery charge reader
http://www.amazon.com/gp/product/B00065L2D8/ref=oh_details_o00_s01_i02?ie=UTF8&psc=1
http://www.amazon.com/gp/product/B000EVWDU0/ref=wms_ohs_product?ie=UTF8&psc=1

>is it just like me going to the store and buying a battery tester nowadays?

Not quite, but it would be like you buying one of these. In this case the load resistance (the wavy part in your pic) which gets hot, is contained within the protective case where the cooling holes are.

TBH i don think that little thing will do much at most it only puts back like 4 watts under ideal circumstances. meanwhile your computer is drawing at least 40watts and phone about 5 watts.

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i use something like this to monitor my battery whenever im listening to the radio or charging my computer. once it gets too low ill turn the car on for a little while. but i also pack a jump starter in all my cars just incase.

https://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0/ref=pd_cp_107_1?pd_rd_w=bySXE&pf_rd_p=ef4dc990-a9ca-4945-ae0b-f8d549198ed6&pf_rd_r=WT057VG43YSGXRCZH4Z2&pd_rd_r=56420b0a-67b9-11e9-aa29-13293a7f6817&pd_rd_wg=y2YGT&pd_rd_i=B000EVWDU0&psc=1&refRID=WT057VG43YSGXRCZH4Z2

Here is one circuit you might be able to build for yourself: http://www.learningaboutelectronics.com/Articles/Voltage-level-indicator-with-a-zener-diode.php


Here is a pre-assembled LED voltage bar, (might be too big though) https://www.amazon.com/dp/B07GGVV46T/ref=sspa_dk_detail_6?psc=1&pd_rd_i=B07GGVV46T&pd_rd_w=LrOVg&pf_rd_p=10ebaf99-73de-4f5d-a994-e7f5fc52f86f&pd_rd_wg=lh6B3&pf_rd_r=2PGC63FBX3YE7CHX6K6T&pd_rd_r=d526f036-2dff-11e9-b05b-55823f4364c8


I don't know anything about RC planes, but motor control is sometimes done through pulsing the voltages at different rates instead of just providing less or more voltage- I don't think these types of meters would work on the pulsed type control.

It is a marine battery monitor, available in blue and green oled. It has a limited application for our purposes, namely it is preprogrammed for a series of voltages. It will read a 3s, 4s, 5s, or 6s lipo pack. This is a 3s build.

Battery Meter, DROK Blue... https://www.amazon.com/dp/B01LQ7MT4K?ref=ppx_pop_mob_ap_share

I don't put much stock in those testers compared to a good invasive load tester. but the cost isn't worth it for something you use every five years and every parts store in town does better for free.

I would preemptively replace a battery of that age, especially if you have any cold weather to speak of.

Before they made sealed cells you had to top them off with distilled water. You measured the specific gravity with the hydrometer to get the right balance with the water and sulfuric acid.

https://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO

It looks like the 1999 Escort uses a serpentine belt and thus does not require manual adjustment, so I doubt your belt is slipping unless certain conditions exist:

• The belt is very old and worn/cracked, or
  
• The belt tensioner isn't working properly anymore
  
  Check the belt and the tensioner first.
  
  It might be possible that your alternator is supplying too much voltage, actually. Possibly due to a faulty regulator. I'm not sure if the alternator test carried out at O'Reilly's would detect that if it's only done with the engine at idle.
  
  Apparently the '99 Escort doesn't have any battery gauge on the instrument cluster, but just an idiot light. You might want to check the voltage while driving or increasing the engine RPM to see what's actually going on.
  
  Something similar to this thing could be useful and also probably the easiest way. Alternatively, just get a volt meter and check the voltage right at the battery terminals while revving the engine.
  
  

https://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0

If your battery has maintenance caps on it, you can buy a cheap battery hydrometer that reads specific gravity of the battery acid in the cells of the battery. Also check your battery fluid levels, adding distilled water if one or more is low.

It's quite easy to do and the hydrometer tester tells you the state of charge your battery is and if you have one or more cells (each tube is a cell) are bad. Instructions are on the tool itself, and there are hundreds of how-to's on Youtube.

A cheap multimeter, which can be had for like $8-12 at Walmart or any auto parts store, would be good to have. Just put it on Volts DC mode and put the probes on the red and black and see what your voltage is.

I have one of these volt meters that plugs into the 12v socket so you can monitor voltage when driving. Very handy. Voltage should be ~14 volts while running and ~12.x while stopped.

You can do this with a regular multimeter but sometimes it's helpful to be able to keep an eye on it while driving.

Use your starter pack to start the car and leave the duff battery on to regulate the power supply and soak up some current from the alternator.

If your starter pack is lithium definitely don't leave it connected you'll damage it and maybe cause it to catch fire. If you have a lead acid one then still don't as if one of the clips shorts against the chassis while driving that could also cause a fire.

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If you can't afford a new battery then on Monday I'd go to a scrap yard and ask if you can do a straight swap for your duff battery and a similar sized working one they've taken out of a car they've recently scrapped.

I have a few electric fences for livestock, I don't bother with fancy deep-discharge gel batteries, and I never bother charging them either. When they go flat I just swap them for working ones at the scrap yard (which happens to be next door to my farm). They never charge me anything.

It helps if you've got a battery load tester which can apply a heavy resistive load to simulate cranking, as just testing the voltage isn't enough to determine if a battery is good or not.

https://www.amazon.com/gp/aw/d/B01LQ7MT4K/ref=pd_aw_lpo_328_bs_tr_img_1/139-0462729-0348330?ie=UTF8&psc=1&refRID=QYV4J2GYADP6R1B9H1FN
Its $13 actually. Looks the same as above one!

Among the other great advice in this thread, keep in mind that the factory chargers are horrible at best. They are mostly two stage chargers that wreck havoc with lead acid/AGM batteries. It is possible that you are not getting a full charge. You may want to get a hydrometer battery tester and see exactly where each cell is at.

I also highly recommend four stage charger such as the Progressive Dynamics PD9200 charger converter. One of the best parts of the Progressive Dynamics charge wizard is it will do a quick desulfation every 21 hours. Another great line of chargers are by IOTA Engineering.

Even if this is something else the proper charger will save you money and give you better performance in the long run.

Uhh... ammeter is a bit of a misnomer there. You'd need something like a battery load tester to handle that much current safely!

How many miles are on the car?
If I had to be like OJ and take a stab at it, I am thinking that a piece of snow or ice got someplace where it shouldn't be.

Get one of these and use it (some Walmarts and Harbor Freights have them or something similar):
https://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0

Just ordered one of these

https://www.amazon.com/Cartman-12V-Battery-Alternator-Tester/dp/B00EXIEVO6/ref=sr_1_1?ie=UTF8&qid=1488075924&sr=8-1&keywords=car+battery+checker

As long as you're taking some long drives or you're doing extra charging at the correct voltage for AGM you should be good without a diode mod, I'm not sure how the voltage regulator works exactly, but I'm guessing this just tricks it into regulating at a higher voltage since silicon diodes have a forward voltage of about 0.7v this would raise an alternator putting out 14.2v to 14.9v. How the stock regulator adjusts for bulk, absorption, equalization, and float charge I'm not sure, and I'm not sure how this mod would effect it. But it looks like enough people have done it that if there were issues it would be known by now, I wouldn't do as some people are doing and just putting a diode in place of a fuse, but put it in line with a fuse like the product above is with an add a circuit mod.

I'd just get a cheap volt meter to measure usage. As long as the battery isn't under much load, it should be accurate enough. Typically you don't want to run a deep cycle battery below 50% for best life, though you can go down to 20% occasionally without much damage to a quality deep cycle, for an AGM that is usually 12.2v(50% @80ºF) and 11.8v(20% @80ºF) with full charge being around 12.8v after the float charge is gone. With a big battery like this you could probably start your truck with 20% charge, but I'd carry a lithium jump pack if I was planning on trying it alone with no one around to jump me.

The switch pro units do look pretty awesome, despite being expensive. Being able to use ignition only wired thing by using the app rather than putting the key in does look like an awesome feature. As well as output dimming for lights that support it. 2 year warranty does seem kind crummy, but I imagine most failure would be DOA/Crib deaths or from abuse, being solid state and not using relays that wear out over time.

A noco G3500 or G7200 is plenty for overnight charging of a single 100ah battery like yours, especially if just topping it off. Get the 7200 if you think you'll go dual battery in the future.

Get yourself one of these lil guys. It checks both your battery and your alternator.

I use one of these on both my starting and house systems.

http://www.amazon.com/gp/product/B000EVWDU0?keywords=voltmeter&qid=1448302823&ref_=sr_1_23&s=automotive&sr=1-23

If you're handy with tools you could probably knock the cigarette lighter adapter off and stick it on the wall wired in to your house system.

If you're designing the system for scratch, it would be nice to include an shunt and ammeter so you can see real time draw on the system.

You might want to get one of these to check things out and keep an eye on it: https://www.amazon.com/gp/product/B07GP1RXYZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I have a 2017 F150.

The F150's have smart charging systems (and AGM batteries) to save gas and deal with all the fancy electronics and auto start/stop system demands put on the battery, it gets complicated. This stuff doesnt necessarily shut off when the truck is off. If you don't have the auto start/stop feature maybe you were spared some of this.

Most likely its time for a new battery though.

I recently purchased one of these handy little gadgets that help me determine intermittent no start issues. http://www.amazon.com/gp/product/B000EVWDU0/ref=oh_details_o01_s00_i01?ie=UTF8&psc=1
You plug it in before starting to get an idea of the level your battery is at, while starting and cranking. Also, you can get a GENERAL idea of battery drain by checking level when you turn car off and checking next morning before starting. Best way is for a shop to hook a test light in the circuit to represent battery draw. However, a minute draw is normal as well. Have you installed anything aftermarket like alarms, amplifiers, or have anything hooked to your cigarette lighter? Anything weird youve noticed with lighting? Also, if you do not connect a boost box, charger, or anything and let it sit, will it start back up later? Also, when the problem occurs and the engine "gives up" do the lights dim down and it starts doing multiple clicks?

would something like this or this be able to tell me?

I think it's more to do with the battery not having enough time to fully charge due to the short driving distance.

Perhaps you should pick up a voltmeter for like $10ish on Amazon.com or a local shop? You can take measurements in the morning when it's not starting well and later in the day when it is starting well. It'll be difficult for the dealership to replicate your driving pattern so perhaps it's best that you do it.

Something like this: http://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0/ref=sr_1_3?ie=UTF8&qid=1406872499&sr=8-3&keywords=voltmeter+car

I have this one but it's a bit more complicated and works on other things also: http://www.amazon.com/Mastech-MS8268-Digital-Manual-Multimeter/dp/B0050LVFS0/ref=sr_1_7?ie=UTF8&qid=1406872598&sr=8-7&keywords=voltmeter

UPDATE:

First off: A huge thank you to all that responded!
Battery was showing 0.9 volts. Jerked it out, replaced with a new battery. Voltage w/vehicle off was about 12.5. Running voltage was about 14.3. I took the old battery, put it on a 2 volt trickle charger for a few hours to put some juice into it and then used a battery load-tester on it (side question: do those things even work? link at bottom of post on what I used). According to the tester, the battery was bad (it's just short of 3-years old, and no, I didn't keep the receipt on it, so even though CostCo has a very generous warranty, I don't believe I can do anything). At this point, I believe it IS just the battery, but I did throw the jumper cables in the back and will have to keep an eye on it. Thanks again to everyone!

Battery-load tester:
http://www.amazon.com/OTC-3180-Battery-Load-Tester/dp/B000F5HU6C

There's a tool called a memory saver, they come in cigarette outlet and OBD plug flavors.

The style you want to use is dependent on the vehicle.

If you want through-hole soldering, I recommend some clock kits. I found one for $4 on eBay and another for $5 on Amazon. There are a lot of options if your budget is larger, just search for "diy solder kit".

If you want SMT soldering, options are sparser, since most SMD/SMT soldering is done by machine. I did find a fun-looking clock kit for $13 on Amazon

Not sure if it's the same thing, but this is what we use around the farm. It's pretty good at telling when a battery is ready to go on the deads pallet.

https://www.amazon.ca/Schumacher-BT-100-Battery-Load-Tester/dp/B000AMBOI0

Right, that's a lot more energy than I was expecting.

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Your best bet, If you're willing to spend a bit of money 30-60US$ is to get a battery fuel gauge or battery tester look for the words "coulomb counter" or "coulomb counting" in the description. The cheaper ones just measure voltage and won't work for what you want. It should be able to measure the capacity of the battery while installed in the bike in the course of normal usage. Coulomb counting is what the method I explained above is doing, The module would do the same thing, tracking the Amp*seconds flowing in/out of the battery over time. IF you run the battery flat it would track the AHrs drawn from it and give you a total value in amp hours that it saw leave the battery since the last full charge.

Here's an example of such a product

Another example

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If you still wanted to try the improvised test method,

A 1KW kettle running on 230V would draw about 4 amps

(1000W/230V=4.34Amps<--drawn by the kettle)

(230V/4.34A=53 Ohms <--resistance of the kettle)

(48V/53 Ohms=0.9A <--kettle would draw from 48V source)

So a little under an amp (0.9 amps) from the 48V SLA battery.

That means it would take almost a day to run down one of those batteries with just one.

Two together would get the time down to about 10 hours and you could just take voltage measurements hourly.

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As to using the motor, It's meant to convert electricity to spinning wheel power, spinning the wheel in the air will draw very little power. Unless you're using the energy to push the bike, there isn't anywhere to put the energy and trying to get the power in by just connecting the battery across a motor winding will just fry it. The reason a kettle or toaster would work here is the energy can go into heating the air or water.

https://www.amazon.com/Cartman-12V-Battery-Alternator-Tester/dp/B00EXIEVO6/ref=sr_1_1?ie=UTF8&qid=1488297718

This is what sparked my question. How would this work?

I got an inexpensive Amazon volt meter, $2.40. It is hooked up so that it is only on when the engine is running. That makes it less accurate because of all the wiring between the battery and the meter.

https://www.amazon.com/gp/product/B00P7QC8PW/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

I use a real volt meter to check the battery voltage in the resting state, unloaded and not being charged, for 8 to 12 hours. I also use a hydrometer to check the specific gravity of the electrolyte. This one looks good, mine is very old.

https://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO/ref=sr_1_3?ie=UTF8&qid=1478312351&sr=8-3&keywords=hydrometer+battery

A really good marine battery monitor system is about $200. I got a battery power analyzer for radio control (RC) toys, $10.55. I use it to measure the current that different things use to figure out how much I'm using.

https://www.amazon.com/gp/product/B019OHZN9M/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1