I am often having trouble getting my car to start and half of the issue I think might be the battery. I only drive my car a few thousand miles a year and it has all the cold start stuff removed and a modded TB. The issue is that after about 5 seconds of cold cranking, my battery will not crank fast enough to start the car. I have taken the battery to advance auto parts and they said it tested good. When I am not driving the car I always keep it on a Battery Tender which keeps it charged. Once running, it works fine and I see 14 volts while driving. I am just looking for confirmation that the battery is dead before buying a new one. It is in an awkward spot and a pain in the *** to change. I can not think of anything else it could be? Thanks

 

Hold a voltmeter to the battery while someone cranks the engine over. If voltage dips below 10v while cranking you have a bad battery.

 

ok, ill check that once it recharges. thanks.

 

could also be a bad starter that drains the battery heavily when cranking
if it cranks slow or uneven off of a charged battery that is a fair chance

maybe try cranking it with a battery from another vehicle and see if it drains that

 

the problem is that its a mini battery (odyssey pc680) mounted in a bin, with a harness bar a few inches over the bin. I can't fit a full size battery in there and it is a pain in the *** to get out. i've got a couple spare starters laying around that I could try. The one that I am using is pretty new (remanufactured).

 

one more thing i forgot to mention. i have some aftermarket gauges that come on with the key to "ON". when i crank the car to start it, all of the gauges turn off until i let go of the key.

 

I had my fan to switch on when the key was on,and found that it does suck alot of power out especially when the starter engages.That is on a Optima.
The problem I can see Adam is a Combo of that small Odyssey Battery that has just enough cranking amps to put out to start a "normal" car and the extra stuff off the switch.Can you try the car without any thing hooked up to switch,Just to start it off.,then switch the stuff on?
May not matter if the stuff is switched off at start.(just read that ,sorry)

 

i probably could but i dont think that's the issue. a few small light bulbs in the gauges shouldnt make a big enough difference for the battery to drain.

 

put a jumper box on your battery and see if that fixes your problem. Jumper cables from another car will work too.

dont ever trust autozone testing equitment. in my 9 years experence in the car business ive had there testing machines say a alternator/starter ect say something was good when it was not.

anyway try jumper cables or a jumper box. Ive seen batterys with a bad cell do the exact thing you describe. it basically makes 1/4 of the battery not work intermittantlly.

 

it cranks normally if i jump it from another car/battery

 

battery for sure.

 

sounds like from all the charging on the battery you may have over charged it and boiled the water out of it. try adding water to the cells if you can.

 

IG1 fuses have power w/key to start while IG2 fuses lose power temporarily when the key is put to start but returns power to these fuses when the key springs back to the on position. Your gauges are likely powered by one of the IG2 fuses.

 

the charger does not over charge the battery. it is also not a traditional battery. i cant open it

good to know. i just picked a couple switched 12v sources in the fuse box by the dead pedal

 

I think those batteries are crap. I had the mini like you have do that to me as well as a larger one. I just went with a large AGM from autozone with an 8 year warranty. Problem solved.

 

i bought a braille b2015c battery and all is good now.

 

If it's a small battery the problem could have started in the first place from over-draining it. Something left on after the car stopped, or driving at night with 3 devices running for a long time and the alternator (possibly weak) only putting out 12 V under the heavy load. That'd drain a big battery too but with a big battery you'd have to do it for a full hour or three non-stop. And you wouldn't notice thanks to the battery tender charging back up... until one day it's so overworked it can't hold a charge anymore. Or option #2 everything I just said is BS and it's been X years and that's how long the battery lasts anyway. If you can get those little batteries to go at least 3 years I wouldn't worry about drain issues, I'd just swap them as they die or hunt down some supreme long lasting type but even those can only last so long.

 

^ i actually have a circuit breaker switch and i kill everything once i shut the car off. i think the problem was from using old/used batteries i got from parts cars... i have an almost new OEM alternator and a newly rebuilt starter. the alt puts out over 14v during driving. the braille battery is top of the line so i hope it lasts a little while (it better, it was almost $300). only time will tell i guess.

 

Ya probably. Who knows how old it was already and a battery will age even sitting around doing nothing if it has a partial charge. Keeping them full on a trickle charger in storage helps but even then they age slightly.