Automotive

Car Batteries - FAQ, General Information, Tips & Tricks

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Oct 26, 2003
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got honda civic 2003, replaced both battery and alternator, tested both and they are good but the battery light signal on dash still on, pretty sure it's an issue with the signal cable to the dash, is there anyway to confirm or replace?
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Jan 27, 2006
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divx wrote: got honda civic 2003, replaced both battery and alternator, tested both and they are good but the battery light signal on dash still on, pretty sure it's an issue with the signal cable to the dash, is there anyway to confirm or replace?
How was the battery tested?
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Oct 26, 2003
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craftsman wrote: How was the battery tested?
load tested by mechanic at the shop with a special battery tester, same as the alternator, they are both brand new. pretty sure it is a signal issue at this point.
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Jan 27, 2006
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divx wrote: load tested by mechanic at the shop with a special battery tester, same as the alternator, they are both brand new. pretty sure it is a signal issue at this point.
There's a lot of threads on the 'net that seem very similar to your issue - try googling 'honda civic 2003 battery light'. A few of the threads out there actually found various solutions (ie - https://honda-tech.com/forums/honda-civ ... s-3019040/).
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Oct 26, 2003
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craftsman wrote: There's a lot of threads on the 'net that seem very similar to your issue - try googling 'honda civic 2003 battery light'. A few of the threads out there actually found various solutions (ie - https://honda-tech.com/forums/honda-civ ... s-3019040/).
thanks, it looks like it might be the ELD issue and needs a Honda 38255-S5A-003 Electronic Load Detector Unit replacement, i ordered a odb2 to confirm the error code, if it shows 1298 then i will proceed to order the eld or 3rd party brand Dorman 601-019. It seems only ebay and amazon have the part and it ships from the states which shipping and custom costs as much as the part itself. Do you know which site RFD member uses to order car parts? I figured there must be a Canadian parts site.
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Jan 27, 2006
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You could try RockAuto.com in the states.
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May 11, 2009
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I just have some questions regarding charging a completely flat battery - my mom hasn't driven her car since November and it has been sitting in the garage, sure enough the battery is dead (Didn't even try to see if it starts - no interior lights, no power locks, no power at all).

Now, there is an old charger/engine starter in the garage - a Motomaster 40/2/200 Amp 6/12V that has sat in the garage unused for the better part of 15 years. Would it still be safe to use? From what I can tell it's a huge heavy transformer in a steel case with a 12v/6V selector, a high/low switch, an ammeter, and a timer knob that goes to 120 and hold. The battery in the car is a AC Delco 75PG 700CCA installed maybe 3 years ago.

Is it as simple as connecting the positive/positive and negative/engine block and setting the timer? If so, what would be an appropriate charge time?

I'm a little concerned since this is not a smart charger, how do I know when the battery is fully charged? Do I just let it charge for ~20 minutes to give it a partial charge and if it starts take a very long drive?
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Jan 4, 2009
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Toronto
I left a brand new car battery (for my Mazda CX-5) on the passenger seat and that battery leaked! I realize there is a small incline with the seat but aren't all batteries supposed to be completely sealed nowadays?!

Was I unlucky and bought a leaking battery or is it true that a minor tilt for ~9 hours enough to cause the acid leaked from the seams?
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Jan 27, 2006
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alfredkcp wrote: I left a brand new car battery (for my Mazda CX-5) on the passenger seat and that battery leaked! I realize there is a small incline with the seat but aren't all batteries supposed to be completely sealed nowadays?!

Was I unlucky and bought a leaking battery or is it true that a minor tilt for ~9 hours enough to cause the acid leaked from the seams?
Car batteries are NEVER sealed. Only Sealed Lead Acid or Gel batteries are somewhat sealed as they all have some kind of vent hole to let gas escape so they don't explode.

Chances are that it didn't leak at the seams but through a vent hole or near the terminals.
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Jan 6, 2011
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craftsman wrote: Car batteries are NEVER sealed. Only Sealed Lead Acid or Gel batteries are somewhat sealed as they all have some kind of vent hole to let gas escape so they don't explode.

Chances are that it didn't leak at the seams but through a vent hole or near the terminals.
That explains when EricTheCarGuy demonstrate how top cover could become conductive and cause the battery to drawdown, i.e. road surface not being flat and bumpy.
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Jan 27, 2006
21844 posts
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Vancouver, BC
M1K3Z0R wrote: I just have some questions regarding charging a completely flat battery - my mom hasn't driven her car since November and it has been sitting in the garage, sure enough the battery is dead (Didn't even try to see if it starts - no interior lights, no power locks, no power at all).

Now, there is an old charger/engine starter in the garage - a Motomaster 40/2/200 Amp 6/12V that has sat in the garage unused for the better part of 15 years. Would it still be safe to use? From what I can tell it's a huge heavy transformer in a steel case with a 12v/6V selector, a high/low switch, an ammeter, and a timer knob that goes to 120 and hold. The battery in the car is a AC Delco 75PG 700CCA installed maybe 3 years ago.

Is it as simple as connecting the positive/positive and negative/engine block and setting the timer? If so, what would be an appropriate charge time?

I'm a little concerned since this is not a smart charger, how do I know when the battery is fully charged? Do I just let it charge for ~20 minutes to give it a partial charge and if it starts take a very long drive?
People have been charging batteries with something similar that you have for the decades so it's safe provided you use it right.

Charging time will depend on the rate of charge that you use (DON'T use the 200A unless you know what's going on) and the capacity of the battery in question (in Amp Hours - AH). Most car batteries have anywhere from 20 to 40 or so AH. So, let's say that the battery is 40 AH (please check yourself as I don't know and just made up this number)... and let's say you use the 40A setting. Then in ONE hour that battery would have received 40 AH of charge and in a perfect world with a new battery, that battery would be FULL.

But we don't live in a perfect world SO, it would normally take longer than 1 hour as batteries charge slower as they get closer to full so think 1.5 Hours. Also, we don't know if the battery will take a full charge anymore as it's 3 years old. Heck, we don't know if the battery will take any charge right now! I would remove the battery from the car, clean the battery off (soap and water), check to see if there are any fluids in the battery and fill so that the fluid just covers the plates but no more, connect the battery to the charger, select 12V, select 2A (nothing higher until you know that the battery will charge), then let the sucker fly. Check the voltmeter to see if the voltage increases steadily for about an hour. If it does, then you have just put in 2 AH into the battery! At that point, you have a choice of either going to 40 A (which I don't recommend) or leaving at 2A and slowly charge the battery according to the capacity of the battery. If you go the slow route, check every few hours to see that everything to go fine and the fluid levels are OKAY. If you do decide to use the 40A mode (which I don't recommend), have a fire extinguisher handy, remove the filler caps of the battery, and stay with the battery through the charging process.
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Oct 6, 2007
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Kootenays
What kind of moron downvotes a thread that the OP took the time to research and post for the good of all here? Get a bloody life! Thanks, OP.
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Feb 14, 2002
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Would it be relevant to also talk about what happens after a battery is restored? For example, your radio may require a 6-digit "anti-theft" code to start working again.

The code is usually unique to your vehicle. You can find that code typically on a plastic card in your car manual package. If not, you may need to contact the dealer. Some makes such as Honda and Volvo will allow you to request the code online.
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Dec 23, 2003
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smacd wrote: What kind of moron downvotes a thread that the OP took the time to research and post for the good of all here? Get a bloody life! Thanks, OP.
Thanks smacd for your kind words.

For those who downvoted this thread, could they please tell me why?

Thanks
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Dec 23, 2003
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quanta wrote: Would it be relevant to also talk about what happens after a battery is restored? For example, your radio may require a 6-digit "anti-theft" code to start working again.

The code is usually unique to your vehicle. You can find that code typically on a plastic card in your car manual package. If not, you may need to contact the dealer. Some makes such as Honda and Volvo will allow you to request the code online.
Good suggestion. I just added a blurb about this as well as a link to a video that may be of help to those with Honda vehicles.
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May 1, 2012
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smacd wrote: What kind of moron downvotes a thread that the OP took the time to research and post for the good of all here? Get a bloody life! Thanks, OP.
One moron. I kinda wanna know who it is.
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Jan 6, 2011
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Purchased this $25USD, https://www.ebay.com/itm/AUTOOL-BT-360- ... 2749.l2649

Did the testing today, literally minutes.

Though my results were unstable, does that imply the battery is close to being dead?
1. Battery Test: First run=Good Health; Second run=Replace, State of Health=22%, State of Charge 73%, 12.44V, 405A/795CCA, R=7.96mOhm
2. Cranking Test: First run=Low, 9.46V, Time=2498ms; second run=cranking normal, 9.66V, time=1540ms
3. Charging: Both runs normal, Loaded=14.04V, Unloaded=14.50V

Should I test when cold or warm?
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Jan 27, 2006
21844 posts
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Vancouver, BC
LongLiveRFD wrote: Purchased this $25USD, https://www.ebay.com/itm/AUTOOL-BT-360- ... 2749.l2649

Did the testing today, literally minutes.

Though my results were unstable, does that imply the battery is close to being dead?
1. Battery Test: First run=Good Health; Second run=Replace, State of Health=22%, State of Charge 73%, 12.44V, 405A/795CCA, R=7.96mOhm
2. Cranking Test: First run=Low, 9.46V, Time=2498ms; second run=cranking normal, 9.66V, time=1540ms
3. Charging: Both runs normal, Loaded=14.04V, Unloaded=14.50V

Should I test when cold or warm?
Battery performance will depend on the temperature of the battery. In theory, CCA is supposed to compensate for that but realistically, I've found that testing CCA in cold weather will drop the CCA performance in regards to warmer weather (usually about 10 to 15%). The other issue is if you recently charged or ran the car within the last few hours. If you did, the battery has a surface charge of some degree which will need to be dissipated before a reliable test can be done.

Questions -
* Are you seeing any issues in starting your car?
* How old is the battery?
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Oct 26, 2008
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Victoria, BC
Battery testing is not an exact science - as evidenced by your contrasting results minutes apart.

That is the sort of tester Walmart uses, though their's is probably better quality.
Assuming yours is broadly accurate, the fact that you only got 22% SOH on the 2nd. run suggests to me that your battery is on borrowed time.
SOC will of course vary quite a bit depending on when you test it, but SOH should be relatively constant.

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