Car doesn't start because of weak battery. But starts after 4 tries. Why?

[phucheneh]

Eh, I don't think it's worth installing another battery and the proper wiring. And I don't think the OP has the capabilities.

The solution to that just lies in changing habits. I run a little inverter in my console a decent bit (maybe once every few days), usually to power a flourescent work light. Not sure of power consumption, but it's on for a while sometimes. Occasionally to charge my generic 15" laptop. I've got no battery issues; I just do it as little as I can manage, and run the engine if I suspect I'm going at it a little too hard.

I should really install a voltmeter...that would be a better solution for the OP, as well, IMO. And a big sign next to it that says 'if below 12.3v, start the damn engine.'

The '12.3v' part is arguable, but assuming no surface charge and a good battery, that should be about 50% charged. I wouldn't go below 12.2, as that's pushing below 40% or so. IIRC SOC range is about 11.7 to 12.6, but on a graph, the slope gradually lessens as you get closer to 100%. I.e. 12.15v, despite being the middle number, is well below 50%, and voltage continues to drop at an increasing rate below that. A healthy battery can usually start a car below 12v, but that's where you start to get into whole 'deep cycling' thing.

I'm rambling...basically, solution to deep cycling problem: don't deep cycle.

 

[LTC8K6]

http://www.conrad-uk.com/ce/en/product/844608/12V-Digital-Timer-Switch

http://www.conrad-uk.com/ce/en/product/841019/12V-Programmable-Digital-Timer-Switch

 

[phucheneh]

I'd rather have something that switched at a set voltage. Or included it as a backup.

 

[LTC8K6]

I'd rather have something that switched at a set voltage. Or included it as a backup.

I think the original problem was forgetting to turn things off.

I haven't seen those timers for sale in the US anyway.

I think it was already suggested in an earlier thread to just buy one of those jump starter/power packs that had a built in inverter and run things off of that and not mess with the vehicle battery.

Something like this, which has a lot of flexibility for powering or charging things.

http://www.walmart.com/ip/Peak-450A-Jump-Starter-Power-Inverter-with-Inflator/15127233

 

[BUTCH1]

I did a quick price check on Optima Yellow top on google... why would anybody drop $200+ (tax + recycling fee) on a battery for a daily commuter? I got my friend a Costco 51R battery for $65, runs perfectly in a Honda Fit.

He mentioned running electronics in the OP might be why he opted for a bigger battery, either way it should not take 4 attempts to finally get it started, OP, start with the basics, is the fuel pump reaching spec pressure?, has the throttle body ever been cleaned? throwing any codes?...

 

[onza]

Are Optima batteries supposed to suck or something?

The only thing that sucks is the way you respond to concerns and questions that are left by others trying to help you.

Please take the time to READ and then RESPOND using something more than one liners.

Maybe then you can figure out your problem.

./rant

 

[onza]

Also - if he was smart, he would have just disconnected the battery from the terminals for four months instead of leaving it hooked up.

 

[fuzzybabybunny]

Guys, I bought the Optima Yellow Top in 51R for $160 shipped.

The guys at O'Reilly Auto wanted $120 + 10% tax = $132 for a standard battery made to fit the Fit's small dimensions.

For a standard 51R battery they want $100 + 10% tax = $110.

For $50 more I thought that I would get a battery that would last a LOT longer.

Unfortunately it's out of warranty since I bought it in Sept 2011.

Where are you guys finding batteries for $60?

 

[fuzzybabybunny]

Also - if he was smart, he would have just disconnected the battery from the terminals for four months instead of leaving it hooked up.

I was planning on being gone for 2 months, but that unexpectedly changed to 4 months. I had friends nearby who could drive the car from time to time but the registration lapsed and I wasn't around to renew it, so they couldn't / wouldn't drive it.

 

[fuzzybabybunny]

I think the original problem was forgetting to turn things off.

I haven't seen those timers for sale in the US anyway.

I think it was already suggested in an earlier thread to just buy one of those jump starter/power packs that had a built in inverter and run things off of that and not mess with the vehicle battery.

Something like this, which has a lot of flexibility for powering or charging things.

http://www.walmart.com/ip/Peak-450A-...lator/15127233

I have one. It specifically says in the manual that using the car to recharge the external battery is not optimal, for whatever reason.

 

[imagoon]

I was planning on being gone for 2 months, but that unexpectedly changed to 4 months. I had friends nearby who could drive the car from time to time but the registration lapsed and I wasn't around to renew it, so they couldn't / wouldn't drive it.

The better option would have been a trickle charger or asking someone disconnect the battery. The small trickle charger I use on my motorcycle was $60. Bike spins right up when I start it monthly because of it.

 

[fuzzybabybunny]

I own 2 multimeters but everything that I have is in storage and after attempting to find one of them I wasn't able to locate it. I really don't want to buy a 3rd multimeter, even if it's cheap. Just seems wasteful.

I went to the auto parts store this morning (jumped the car, drove 2 miles to the store) and they hooked it up to a battery tester that said Bad Battery. They had to input the CCA spec (I think) and the voltage read 11.86V. The car still fired up, albeit barely. I'm not sure how their battery tester determines if a battery is bad or of a battery is simply low?

 

[imagoon]

I have one. It specifically says in the manual that using the car to recharge the external battery is not optimal, for whatever reason.

The car's charging system is designed to top off the battery, not charge if from dead. Doing so can cause damage to the alternator, regulator (if equipped), battery terminals, wiring and potentially other stuff if the alternator fails in a bad way such as jumping voltage up to 30vdc. You can charge alternate batteries in a car as long as there is an isolator and current limiter in place.

 

[fuzzybabybunny]

The better option would have been a trickle charger or asking someone disconnect the battery. The small trickle charger I use on my motorcycle was $60. Bike spins right up when I start it monthly because of it.

I have this lying around:

http://batteryminders.com/pics/products/hi_res/12151.jpg

I was going to unplug the battery and charge it with this overnight. Is that too short of a time to charge?

 

[LTC8K6]

I own 2 multimeters but everything that I have is in storage and after attempting to find one of them I wasn't able to locate it. I really don't want to buy a 3rd multimeter, even if it's cheap. Just seems wasteful.

I went to the auto parts store this morning (jumped the car, drove 2 miles to the store) and they hooked it up to a battery tester that said Bad Battery. They had to input the CCA spec (I think) and the voltage read 11.86V. The car still fired up, albeit barely. I'm not sure how their battery tester determines if a battery is bad or of a battery is simply low?

You put an appropriate load on the battery and measure the voltage. The battery is out of spec if the voltage is too low with the test load applied.

Leaving it for a few months to discharge to a very low state probably damaged it.

 

[imagoon]

I own 2 multimeters but everything that I have is in storage and after attempting to find one of them I wasn't able to locate it. I really don't want to buy a 3rd multimeter, even if it's cheap. Just seems wasteful.

I went to the auto parts store this morning (jumped the car, drove 2 miles to the store) and they hooked it up to a battery tester that said Bad Battery. They had to input the CCA spec (I think) and the voltage read 11.86V. The car still fired up, albeit barely. I'm not sure how their battery tester determines if a battery is bad or of a battery is simply low?

A bad batteries voltage delta is much larger than a discharged one. Basically (random example) starting at 12 volts, putting a 200amp load may drop a bad battery to 10.5 volts, while a good but discharged one would be 11.5 etc. When the load is removed, the bounce back time is longer on a bad battery also, IE time that it goes from 10.5 -> 12v takes longer than a good but weak cell. You can also measure battery internal resistance. higher than spec -> bad.

 

[fuzzybabybunny]

The car's charging system is designed to top off the battery, not charge if from dead. Doing so can cause damage to the alternator, regulator (if equipped), battery terminals, wiring and potentially other stuff if the alternator fails in a bad way such as jumping voltage up to 30vdc. You can charge alternate batteries in a car as long as there is an isolator and current limiter in place.

I've always wondered this - why would charging a low battery put added strain on an alternator? What kind of strain? The current draw could remain steady. The voltage supplied could remain steady. What kind of added strain?

The battery pack charges via a 110V plug. I can just plug my 120W inverter into it while driving and it'll charge safely just like that?

 

[imagoon]

I have this lying around:

http://batteryminders.com/pics/products/hi_res/12151.jpg

I was going to unplug the battery and charge it with this overnight. Is that too short of a time to charge?

Well first that should have been on the battery in the car when you left but at 1.5 amps, I would expect that it might take days to charge if it can actually recover the cell. I would plug it in and try it however.

 

[fuzzybabybunny]

A bad batteries voltage delta is much larger than a discharged one. Basically (random example) starting at 12 volts, putting a 200amp load may drop a bad battery to 10.5 volts, while a good but discharged one would be 11.5 etc. When the load is removed, the bounce back time is longer on a bad battery also, IE time that it goes from 10.5 -> 12v takes longer than a good but weak cell. You can also measure battery internal resistance. higher than spec -> bad.

Ah I see. So since their battery tester said that it's a bad battery, I should basically just chuck it? No use hooking it up to my trickle charger / desulfinator thing?

 

[LTC8K6]

I have one. It specifically says in the manual that using the car to recharge the external battery is not optimal, for whatever reason.

So plug it in when you get home to recharge...

 

[imagoon]

I've always wondered this - why would charging a low battery put added strain on an alternator? What kind of strain? The current draw could remain steady. The voltage supplied could remain steady. What kind of added strain?

The battery pack charges via a 110V plug. I can just plug my 120W inverter into it while driving and it'll charge safely just like that?

You need to connect it to 110V. If the alternator cannot charge it properly, it isn't going to charge it properly when connected to an inverter that runs a charger. Perpetual motion / free energy doesn't exist.

Lead acid batteries vary the amount of current they pull during charging based on the voltage of the cells. I don't know the total power of the Fit alternator but to put it mildly, 130 amp alts are common in other vehicles and a 600 amp CCA battery can sink 300-350 amps pretty easily at a low charge. (This the reason there are current limiters on most chargers. Typically 20 amps.) Typically the wiring in the car isn't designed for that level of pull and acts as a natural current limiter which heats / burns the wires over time.

 

[phucheneh]

They used a conductance tester to check it. It uses principles that don't require a full charge in order to make a decision; however, 'charge and retest' is a possible result for it to give.

'Bad battery,' unless there is a specific issue like a bad cell, simply means the capacity of the battery is diminished a fair amount below what it's rated at. It's possible to drive for a year or two, easy, on what a midtronics tester deems to be 'bad.'

11.86v is nearly entirely discharged. I would remove the battery and have the parts store do a 'diagnostic charge.' Essentially, put the battery on an autocharger then test again. If it's, say, a 600cca battery and the tester says 500cca, I wouldn't worry all that much about it- you just need to ensure the charging system is up to snuff and quit draining the batt with the car off.

It does not hurt a modern car to jump start and let the charging system do its work. It's just not going to charge particularly fast, and it could MARGINALLY decrease the life of the more sensitive parts of your alternator (voltage regulator and rectifier bridge). I think the whole 'oh noes alternators can't recharge batteries!' thing came from old shitty cars with inadequate wiring. In the 80's, there were GM's that relied on what was, at best, a freakin' 8ga cable run from the alternator to the starter (often ~4ft of cable), then a more proper 4ga cable to the battery. That system was capable of safely carrying, I dunno, maybe forty amps. Which was absurd.

 

[imagoon]

They used a conductance tester to check it. It uses principles that don't require a full charge in order to make a decision; however, 'charge and retest' is a possible result for it to give.

'Bad battery,' unless there is a specific issue like a bad cell, simply means the capacity of the battery is diminished a fair amount below what it's rated at. It's possible to drive for a year or two, easy, on what a midtronics tester deems to be 'bad.'

11.86v is nearly entirely discharged. I would remove the battery and have the parts store do a 'diagnostic charge.' Essentially, put the battery on an autocharger then test again. If it's, say, a 600cca battery and the tester says 500cca, I wouldn't worry all that much about it- you just need to ensure the charging system is up to snuff and quit draining the batt with the car off.

It does not hurt a modern car to jump start and let the charging system do its work. It's just not going to charge particularly fast, and it could MARGINALLY decrease the life of the more sensitive parts of your alternator (voltage regulator and rectifier bridge). I think the whole 'oh noes alternators can't recharge batteries!' thing came from old shitty cars with inadequate wiring. In the 80's, there were GM's that relied on what was, at best, a freakin' 8ga cable run from the alternator to the starter (often ~4ft of cable), then a more proper 4ga cable to the battery. That system was capable of safely carrying, I dunno, maybe forty amps. Which was absurd.

It has more to do with running a device at or above 100% load for hours. A truly dead lead acid battery can draw quite a bit of power. A car with a 130amp alt running at 135+amps while still running the car itself will fry itself or the its diode set in a fairly short amount of time. There is no current limit between the battery and alt peg.

 

[LTC8K6]

Here's probably what you need. It has a large battery, a built in inverter, and can be charged from 120V or 12V sources. So you can charge it while you drive.

http://www.batterychargers.com/ProductDetail.aspx?ProductName=94026931

http://www.batterychargers.com/Documents/0099001253-00.pdf

 

[fuzzybabybunny]

Well first that should have been on the battery in the car when you left but at 1.5 amps, I would expect that it might take days to charge if it can actually recover the cell. I would plug it in and try it however.

It looks like the battery is 38 Ah, so at 1.5 amps it should take maybe 24 hours of charging?