new battery or try battery tender?

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Dec 28, 2009
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canada
Hi guys

I have a 05 honda crv that has a group 51 battery. Currently it has a walmart ever start (non maxx), previous owner changed at 2017.

The vehicle is parked outside all the time, used monday-friday to work, stop and go traffic 30mins commute.

Now if it sits for 1 or 2 days in -30C the car will not start. The battery is not completely depleted, as the dash lights, and accessories power up, but doesn't have enough juice to turn.

Would you guys recommend me purchasing a smart battery tender/charger? I have my eye on this ctek rated for winter weather. https://www.amazon.ca/CTEK-56-958-Automatic-Extreme-Climate/dp/B00GODCLYU?ref_=ast_sto_dp

But for the same price I can get a Costco kirkland battery for 109 + tax.
 
I think the plan with the best long-term effect would be to get the charger and see if it helps. If it doesn't, replace the battery and maintain the new one with the charger.

If it's a choice between the battery or the charger, get the battery. It's a bit of a gamble, but in my experience under those conditions, the chances of your battery being on its way out at this point are relatively high.
 
IF you have the ability to plug in regularly, a maintainer or a small charger maintainer will greatly increase the life of your batteries.

2017 to 2021 is a very short life, and I'd wager you could double that with regular maintenance.

If you cant regularly plug in just get a new battery at this stage.
If you can you should have a maintainer and Id get one now and see if you can recover this and get through another winter.
 
If you don't have the money for both I agree with the others to get a new battery but you should have some sort of charger/maintainer and that Ctek 4.3 would be a good one. I have an older 4.3 with out the test feature, if mine ever stops working that's the one I would look into.


I also suggest getting the bumper for them, it keeps them from sliding around.

 
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Thanks guys for the reply. I haven't done a load test, but I can bring the battery in to a local shop that can do it free of charge.

But either way I still want to get a smart charger for my other vehicles to top them up as well. Ive read review on the ctek and noco but the Operating Temperature: -4° to 104° F (-20° to 40° C) for both. It gets -35C - 40C here.

If need be I can get a battery, but I would like to try and salvage this battery, and based on reviews on amazon, and other forums these smart chargers are able to extend the life of the battery(depending on age and previous care ofcourse)

EDIT the CTEK 4.3 polar is rated to work at -30C, but seems like a -10C is not big of a deal if I leave it in the engine bay with the hood closed.
I would like to get the CTEK multi US 7002 which is 7amp vs 4.3amps. But does this matter? its just fast charging with 7amps?
 
I just bought a battery charger after reading all this about charging systems taking 3 hours to go from 80-100% state of charge....learned just this year that my 05 Silverado drops charge voltage down to as low as 12.4v (more commonly 13v) when it decides the battery is charged "good enough".

When I first hooked up the battery charger it said "on" and took a few minutes to show stare of charge (100%). I was a little dumbfounded as I expected something like 80-90% based on all that I read on here. I cycled it on and off and got it to show 97% charge, let it charge 15 minutes and it was up to 100%.

Then I put it on my fiance's 2013 Sonata which does nothing but very short trips and sits in the driveway. It was at 84%. I can understand how it would be low, I actually expected worse since it is getting cold out now and sits a lot.

Obviously though the "smart charging" on the gm truck is smarter than I was lead to believe here on bitog. Wouldn't be the first time I guess.

Update: I just researched a bit more and apparently the "surface charge" needs to be removed. I did that with headlights and blower motor for a couple minutes and now it's at 57% charge. The fiancee told me not to charge it until lower rates at 7pm so it has to wait. Will see in the morning what it's at after 13 hours or so of charging.
 
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I have never gotten much more than 3 years out of the Mickey Mouse 51R battery in my wife's CR-V, regardless of brand or CCA. Your battery is toast, just replace it and move on.
 
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Do a LOAD (not voltage) test? The battery tender is not going to do anything if the battery fail a load test.
This. A group 51 battery is pretty darn small, and smaller batteries tend to have higher impedance. So that plus the -30C situation isn’t doing much for you.

I’d want to condemn the battery if need be, and also determine if there are any parasitic drains acting against you.
 
If an hour a day drive won't charge it then it is done
I agree its probably done, but that thats no solution.

He could drive that car all day come back, put it on a smart charger and it will still take more.

Alternators aren't great battery chargers.
 
when I looked for my sisters 2006 Corolla the best deal I could find was a Costco Interstate 35 battery with 3 year full replacement for $78.99...was cheaper than Walmart EverStart Maxx or others I found elsewhere and appeared to be the same battery...

couple of things to add is that a Deltran Battery Tender will not re charge a battery below a certain percentage and only a load test will tell the tale of your battery...I relied on a battery once that "tested" just fine and full power...until a load was applied and it was dead flat...don't let that happen to you...

Good luck with your choice...

Bill
 
I’m used to -30 C. It’s a heck of a challenge on your battery. I would buy an “ intelligent” charger and get it charged up to 100% and do it weekly for a while. If it still gives you trouble, time for a new battery.
 
Good afternoon,

Thank you all for your help and suggestions.

I purchased the ctek mus 4.3 polar and bumper. It was a little more expensive than the noco genius10, but its rated for cold winter weather.

My first instinct was to purchase a new battery. But i will give this a try first. Plus I needed a charger anyway to maintain the other 2 batteries I have.


As for load testing, I'll have to remove the battery and bring it in to my local Canadian tire shop when I have time.
 
When one hooks up a charger, that has a state of charge display, the charger is simply reading the voltage of the battery when it was hooked up. it does not know when the last load or charging source was applied to the battery, and a load or a charging source recently on a battery can have huge effects on voltage. It has no magical powers to read the true state of charge or state of health of the battery, despite the marketing literature trying to imply this near impossibility.

Hook up such a charger while the headlights have been on for 2 minutes, engine off, and it will read alarmingly low, even though the battery could perhaps be 99% charged.

The % charged screen on chargers that provide such, is pretty much useless in most scenarios, as full charge resting voltage can be as low as 12.62 on some batteries and as high as 13.23 on others, and this will also change with battery temperature. Very few chargers have temp sensors on the battery clamp, making any % charged screen even more worthless.

Alternators are controlled by a voltage regulator. which might be located in the alternator itself, or in an engine computer, or sometimes a separate unit on the firewall.
The voltage regulator basically tells the alternator how much amperage to make in order to seek, or to maintain, a certain voltage the voltage regulator is looking for.

So While vehicle charging systems generally are poor at fully charging a battery, it is because the voltage regulator is timid for fear of overcharging and lawyers, and it is usually pretty dumb.

Some vehicles do intentionally manipulate voltage, to squeeze out minutely more MPGs, and do so at the expense of battery life.
Very few vehicles care about returning the battery to a true full charge ASAP for maximum possible battery life. Some older pre 90's vehicles that have a constant setpoint of 14.0v no matter what, in comparison to todays vehicles, would take far better care of the battery, even though long drives it essentially would be overcharging, and for short trip driving with a depleted battery, would not be charging it nearly as fast as 14.4v would.

My battery gets intentionally drained with engine off. powering refrigeration, powertools, portable office My externally regulated alternator(s) were once controlled by a voltage regulator inside engine computer and I found these voltages allowed to be infuriating for my purposes/needs.

I tricked this voltage regulator into thinking it is still connected to an alternator, with a 50 watt 10 ohm resistor, and use an external adjustable voltage regulator further modified to have a voltage dial on my dashboard, next to ammeter and voltmeter. When the battery is well depleted, and I start the engine with regulator set to ~12.4v, only 10 amps or so flow into the battery. My cold alternator at cold engine idle speeds can make 67 amps, but I have to crank up the desired voltage before the alternator makes this much juice. I can hear the note of the v8 engine change as the alternator sucks up 2+ engine HP in order to make this 67 amps to feed the depleted battery and run whatever other DC loads are on at the time.

The healthier and the more depleted the battery, the more amperage it can suck up at any charging voltage reaching the battery terminals. I generally observe 2 to 3x the amperage flowing into the depleted battery when held at 14.7v, compared to 13.6v, but as the battery ages toward the final third of its expected life, this is more like 2x.

When grid power is available, I use an Adjustable voltage power supply capable of 40 amps output to fully charge the battery. It is told to seek 14.7v, and I allow it to maintain 14.7v, until amperage the 100 amp hour group 31 TPPL AGM battery accepts, tapers to 0.5, then reduce voltage to 13.6v.

The Automatic 'smart' chargers I tried, would never hold 14.7v for long enough for the 0.5 amp per 100Ah of capacity threshold, to be reached.
Their green 'full charge' light, was so hideously inaccurate, I am still filled with disgust for them, many years after I quit using them.

I recommend users of battery chargers actually measure amperage the battery is accepting at higher voltages, if they are really trying to achieve true full charge for maximum possible battery longevity, rather than believe the lying BS artist green 'full charge' light.

the green full charge light ONLY indicates the charger has lowered the voltage it will hold the battery at, switching from a constant voltage in the mid 14's, to some float voltage somewhere in the low to mid 13's.

A green light on a smart charger does NOT indicate a truly fully charged battery, in most instances.

Any charging of a depleted battery is better than no recharging, but achieving 98% state of charge is only half as good as 100% charged, in terms of extending battery lifespan and performance during that lifespan. Most smart chargers likely stop holding an absorption voltage in the 92 to 95% charged range, then switch to float voltage. Charging does still occur at float voltage on a less than fully charged still relatively healthy battery, but basically comes to a standstill on a less than healthy battery. On the healthy battery, float voltages will take days to achieve full charge, whereas at absorption voltages in the mid 14's it might take .5 to 3 more hours.

The AGM float voltage setting is usually around 13.6, and on flooded batteries is usually 13.2. Almost all these smart chargers with battery choice buttons, will achieve higher state of charge by the next morning using the AGM setting as some portion of that 12 hours, will be at float voltage.

The AGM setting can also prevent overvoltage that some 12+ amp Schuchargers are famous for applying.

People really only start using a charger regularly on the less than healthy battery, so the premature float voltage initiation, and the lying green light is doing the battery and the battery owner no favors.

LED adjustable voltage power supplies capable of 30 amps can be had for under 25$, but they are far from automatic. They can however truly fully charge a battery back to its remaining potential capacity for the human who demands it and has the desire to operate it, and an Ammeter and or hydrometer.

Much easier to believe a green light though
 
I'd buy a new battery. Used monday-friday is enough to keep a good battery charged.
 
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