Honda Odyssey battery issues

Shorted cells are caused by excessive charging and discharging. With a new battery take a voltage reading while the car is running. You should have a consistent 14.5 Volts. Monitor it for maybe ten minutes to be sure it's consistent. If you have more than 14.5-15 volts, you need a new voltage regulator. Most of the time the regulator is in the alternator, but it could also be part of you power control module.

If your charging voltage is fine, then go back to my original post and look for a drain. You said some lights are already known problems. If these are grounding out while the car is not started, then you are in a pattern of draining the battery and recharging every time you turn it on an off. Excessive discharge and recharge will cause cells to short. Even if its 1 or 2 volts every night for a month. Look for the drain and I'll bet it's on your instrument cluster fuse. Pull the dash an trace your wires from the known bad console lights.

 

Roger that,
I will start running some voltage checks and see what I can turn up.

Thanks for the info.

 

I just found this post, hope somebody is still reading it.

My 09' Honda Odyssey battery is draining overnight. Bought a new battery, it worked okay at first then a few days later, dead again.

I checked the alternator it appears fine. The battery does get charged up while I'm driving (measure > 14V). When I turn off the engine the battery is more than 12 V, but overnight it drops to 9V. I checked that everything is off, lights, radio, heater, ....etc, but something is draining the battery still.

Something that I noticed, which may or may not be related to the battery drain, is the air conditioning. No air is flowing inside the car, even though the fan is set to maximum and I can hear the fan noise. When I pop open the hood, I can see some pipes to the AC is really cold, ice is condensing on it. Yet inside the car it gets hot because no air is circulating. Some earlier posts said the AC clutch can drain the battery, would that explain the hot temperature inside the car?

 

Did you post these instructions somewhere? I'm having a similar problem, and am interested to measure the draw. But unsure how/where to connect the electrical multimeter that I have. (It looks like it can be set as an ammeter, but if I need to buy a different meter I will). Can you post instructions for that? (Or maybe you already did?)

 

Make sure your amp is set to measure current and that the leeds are in the correct ports... Some meters are different with how they are configured, if you don't set it up right and then go measuring amperage you will blow the fuse or the meter itself. Make sure you're set at the highest setting.

To measure current you want to put the meter in-line with your circuit. Disconnect the negative lead from your car battery. Put one lead from the meter on the negative battery post and put the other lead on to the cable you took off the negative lead.

Go open the car door, the interior lights should be on just like normal. Take a look at the meter and note what it reads. Close the door, whenever the interior light goes out you should see a noticeable drop. Within 30-60 seconds later you should see it drop to a minimal draw, but not quite zero.

 

For whatever it's worth, our 'replaced' battery is dead AGAIN. This battery is less than 3 years old too.