I blew up the inverter????

I'm sorry to read this:

They look to be a front for a product liability law office trolling for someone to sue. Product liability lawyers make their money by taking your case and getting 1/3d of any monetary award. To them, you are a means to an ends, their standard of living ... the consumer product version of an "ambulance chaser."

There are real cases of product liability where a court case makes sense. One of my favorite columns is in an engineering magazine from an expert witness ... a profession engineer who does accident investigations. But Consumer Affairs is so far removed from the real world ...

Hopefully you have shared enough that they realize it is a 'dead end' and won't pester you. As for your report showing up on their site, don't worry about it ... we like you anyway. <grins>

Bob Wilson

ps. Let us know if you want to "dump it." <wink>

 

Wow that seems a bit fat, normal would be 13.7 to 14.2 volts, any higher than 14.5 volts can overheat the battery causing electrolyte to evaporate.

From About.com

Bosch regulators are set to 14.2V

 

If true, this is quite high. The normal Prius DC to DC converter should produce a voltage of ~13.8V.

 

Charging at 15.5 volts will give you a 100% charge on Lead-Acid batteries. Once the charging voltage reaches 2.583 volts per cell, charging should stop or be reduced to a trickle charge. Note that flooded batteries MUST bubble (gas) somewhat to insure a full charge, and to mix the electrolyte. Float voltage for Lead-Acid batteries should be about 2.15 to 2.23 volts per cell, or about 12.9-13.4 volts for a 12 volt battery. At higher temperatures (over 85 degrees F) this should be reduced to about 2.10 volts per cell. (NAWS solar forum faq)

The following link has more information about lead/acid batteries than you would ever need to know: http://www.batteryfaq.org/

 

funny enough, he actually has one of those assemblies and a couple of those huge cartridges laying around in his various tools. he looked closely last night and said that he felt it would be a stretch to call one of those a fusible link.

the one he has in mind is inside the inverter case. but again, until we know which one her dealer is talking about, we're shooting in the dark. internet diagnostics is hard enough as it is

 

it's that big metal box next to the engine up front.

 

Hi Ginny,

If you are asking where the inverter is located, it is in the engine compartment near the driver's side fender, and has a shiny aluminum cover on it with the Toyota Hybrid System decal.

The 12V auxiliary battery is located in the hatch in the right rear corner. The brake power supply is located to the left of the battery, and it is helpful to first remove that unit when you want to remove the battery.

 

Oooohhhh, we like you!!

I understand Haynes has finally come out with a hybrid repair book and another is being sold by the Michigan hybrid group. Both books cover the current NHW20 model, your vehicle. I understand both books are fairly affordable, ~$50, and would be a great way to learn where the systems and parts are in your own vehicle. Even if you never touch another part, learning the terms and terminology would give you a power edge when dealing with service technicians.

In the meanwhile, I'd recommend take a peek at good Prius friend Hobbit's work:

Hobbit's techie-rants
​

I think John1701 has some good stuff too.

Bob Wilson

 

I can't stop thinking that some of these tow trucks have Jump Starters (engined powered, 200 amp capable) on them. Not just battery chargers. And the Prius battery is not supposed to be charged above what 3 amps? Because its small, and would overheat.

The Jump Starters are meant to supply enough current to operate the starter motor. Which in a normal car is hundreds of amps.

Could it be these Jump Starters are frying Prius 12 V batteries?

 

I don't think that an external charger could fry (damage) a 12 volt battery during the connect time required for jump starting. It might be a concern, though, if it does supply unusually high voltage to the system.

As stated above, 13.8 volts +/- 0.1 is the happy place for the entire system. We would like to hope that all the electronics could accept, say, 2 volts higher without damage, but it's hard to be sure. If the Prius' 12 volt battery has a high internal resistance, it might not be able to pull down a high voltage, externally supplied.

 

Hi Doug,

This is especially true if the dedicated jump start terminal is used while the battery is ~9 feet away from all of the sensitive and expensive electronics, and you have the resistance of the battery cable plus the internal resistance of the battery to contend with.

 

I think connecting a donor battery to a dead one with reverse polarity is similar to connecting two batteries in series to a load, the difference being the load is replaced by a section of copper wire.

If you take your basic two D-Cell flashlight where the batteries are in series and the load is the bulb, replacing one of the batteries with a dead one results in no light from the bulb; that is no current is flowing through the circuit. Since the only thing changed is the one battery, it seems to me the dead battery must appear as a high value resistor sufficient to prevent the flow of current in the circuit.

If this is true of car batteries too, then it seems to me that connecting the donor battery with reverse polarity should be harmless (to the batteries) as long as the "dead" battery is really dead. The closer the "dead' battery is to not being dead is the more current will flow in what is effectively a short circuit, at the extreme where the "dead" battery is not dead, it's most likely that some part of the jumper cable will vaporize and open the circuit.

Anyway, short circuiting any battery is never a wise move but as long as there is some weaker link in the system than the internal and external conductors of the battery which will fry and break the circuit, they normally survive the ordeal. Short circuiting a series connected battery pack, assuming neither are dead, could result is more stress on the battery's conductors because there is twice (or so) the voltage into same load meaning double (or so) the current; then again the weakest link will also see the additional current and should vaporize even faster.

This is all theory of course, just applying a little ohm's law. I'll not be testing it with my Prius anytime soon.

As far as the rest of the vehicles electrical load goes, I can see how connecting a donor battery to a dead battery could wreak havoc on things. It's reasonable to protect low power circuits with inline diodes so current cannot flow in reverse. Diodes aren't practical for high current circuits because of their forward internal resistance; that's where circuit breakers or fusible links come into play, and that only applies to circuits that's aren't adversely affected by reverse polarity, like a DC motor that would simply rotate in the opposite direction.

Maybe in the future, cars and jumper cables will all be equipped with polarized jump start connectors so they can't be reversed

 

I've never seen a "dead" battery, except ones that have frozen and cracked their cases. Most batteries that are "dead" are discharged below the threshold of being useful. A battery with a dead cell, will hold some charge through all cells for months. A "dead" battery would read 0.0 vvdc.

In the context of this discussion when we describe a battery as dead when it drops below a voltage to energize the needed circuit. So to clarify MISSLEXI"S
comments, I suspect that no car battery that has been in service is indeed dead, and therefore capable of doing the above described damage with reverse polarity.

Icarus

 

Hi All,

Well, I am thinking along the lines if the battery goes open circuit from the overcharge, then there is nothing (or is there ?) to tame the alternator ripple from the starter.

 

If you are thinking about Prius: the DC to DC converter provides 13.8V on the DC bus once the car is READY, drawing upon the power from the traction battery. The DC to DC converter produces a well-filtered and regulated voltage source and the AC ripple is high frequency and relatively minor. If the 12V battery is taken off line after the car is READY, the Prius will continue to operate (Hobbit may have been the first owner to prove this experimentally.)

If you are thinking about a regular automobile: if the 12V battery goes off line, I do not think that the alternator will continue producing power. You are right that the relatively low-tech system assumes the 12V battery will be available to act as a filter for the ripple produced by the alternator.

 

Is the bus the same thats charging the small 12v battery? If so its charging at 14.8-14.9v.

See pic below.....

 

If your meter is accurate, that is way too much voltage for a lead acid battery. Does the battery run warm?

Bob Wilson

 

I hate to differ with you but thats not true.


All cars charge at 14.8. Every car I have ever owned has charged at 14.8. I have used many different multi meters and gauges to verify that fact. To test what I am telling you walk out to your car and start it up. Then place a mulitmeter on the battery terminals or in the 12v power socket. My diesel truck would go as high as 15.4.