12 Volt Battery Service

Not mine. The terminals and clamps were clean to start with, and since they were tightened enough to form a gas-tight seal, opening them up to clean them would only create the possibility of trouble.

 

Your Prius 12v Battery is SEALED (with an over pressure vent tube) so battery acid will not cause the corrosion common in lead acid batteries. There is no need to ever clean the battery. Checking the connections to make sure that they are tight, measuring the battery voltage with your Prius off (It should be more than 12v) and again with the headlights on (the voltage should not drop below 12v) once in a while are the only maintenance items that may be required.

JeffD

 

My OE 12v battery was still good after 8 years and 215k miles with NO maintenance (due to long trips and never discharging the 12v battery) when I replaced it with an Optima Yellow-Top.

JeffD

 

What about the traction battery which is in the same compartment and must be subject to the same corrosion?

 

Actually, you very likely get enough plastic deformation of the metals to create a small gas tight seal, or seals. A circular seal area even 1 mm in diameter would probably work well since there is very good heat sinking around the contact point.

Also, the "skin effect" for current being distributed to the surface of a conductor applies only to AC circuits.

 

There's another recent post mentioning checking the water levels:

12 Battery Maintenance | PriusChat

Also: it's worthwhile hooking up a low amperage trickle charger, just a token level of charge is needed, before disconnecting the battery, to maintain memory.

(I tried PriusChat's search function and completely struck out. But just using Google search with a few key words I remembered: it was the first search result)

Addendum: Just had a look at ours. It says "never add water", and has opaque black case. I believe it's not like traditional lead-acid battery, has liquid, but not sloshing around: it's in some mesh medium. Guess I'd just leave it alone.

 

the secret to longevity of the prius battery is buying the prius before it sits around on the dealer lot and never letting it discharge. my 04 lasted 8 years, my 08 is coming up on 5 years and i expect my pip to do as well. if you bought your prius after used, or after the dealer had it more than a month or two, or you let it discharge by leaving somrthing on, all bets are off and i don't know if cleaning the terminals will extend longevity or not.

 

The early (Gen1 2001=2003) Prii HV batteries did suffer from corrosion of the "Bus Bars", but that was due to leaking electrolyte from the HV Battery Modules, not the 12v battery. Corrosion has not been a problem since the HV battery modules were improved for the 2004 model year. The HV battery modules were improved (reduced effective series resistance) again for the 2010 model year Prius.

JeffD

 

Or get one so long on the lot that the 12 volt is totally dead, and get it replaced prior to the sale. That was our situation.

 

Well, my '06 12v battery after 6 years of silence was dry as a bone, filled it with distilled water, charged it and it's holding a charge, put it on the lawn mower, so I'd clean the teminales, coat the connections with a dielectric grease, fill the six chambers with distilled water, once a year and top off with a 2amp charge once a month for longevity,ymho,ymmv.

 

HAH ????

This is only through for quite high frequency AC and we are not talking about the 60Hz neighbourhoud !!

So the AWG rating just bogus right NO need for thicker cable for higher current !!!!

Where did you get this ??? I am E.E so please believe me AC and even home DC is flowing "troughout" the cable material and thickness does mattter (other example fuses !!)

 

I put a drop or two of "bar & chain oil" on each battery post when my Prius was new (3 years). Bar & chain oil has a sticky additive making it cling to metal and gives a long lasting air / moisture tight seal.

I do this with all my batteries, AGM and flooded cell. It keeps the terminals free of corrosion.

 

You are NOT correct it will NOT flow outside ever ! Energy maybe in some very "interesting" cases again you are wrong. In an automotive setup NO electricity will "flow outside of a conductor"
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It seems to me you do NOT really have even the basic understanding about this. Yes voltage is dropping but it is because of the resistance (increase) at the contacts (which are not perfect any more due to some corrosion) this is not what damage anything ... most stuff in your car has its own DC/DC converter built in and will be happy with the "dropped voltages" probably way down when the batter is already dead. Please if you do not understand this just leave the details out....or to the "perfectionists". And if the car is able to start (well before devices you mention even come to life) the HV WILL maintain the desired "voltage".

The only valid point is that THE car becomes less efficient ... and maybe you can not fully charge the battery. However you are 100% right that it is a good idea to keep the voltage drop due to some corrosion on the terminals to the minimum and that can be done with some LTC ... but the rest of semi scientific thing PLEASE !!!

This part is OK with me personal opinion something which is not measurable

 

No I am not !!! This still totally incorrect .. leaving out the details current WILL NOT flow outside of the material. ENERGY in form of "electromagnetic field" effect introduced by the conductive material and current may. There is NO current in vacum but of course ENERGY can flow through ... I know this is black magic.g

So chill I am not distorting anything .. NOTHING goes OUTSIDE of the conductive material (in any of the Prius use case anyway ... ) ... however surface oxidation/corrosion is a possible issue but not for the reason you stated ... that is all.

 

Current can and does flow through a vacuum if it did not the old style radio and tv valves "tubes" would not work.
It has also been proved that high voltages travel along the outside "skin" of a conductor.