What Kind Of Charger For Hybrid Battery

Hi Myrelle, let's step back for a moment. Are you talking about the 12v battery in the right rear fender area? If so, that is your 12v auxiliary battery. Your high voltage hybrid battery is located behind your rear seat and below the cargo area deck.

Questions:

1. Do you drive it everyday?
2. How many miles per trip/how many trips?
3. What is the indication you need a new battery?
4. How many total miles on vehicle?
5. Any there warning lights when you are having issues?
6. If #5 did you have the trouble codes read?
7. If #6 generic obd2 reader, mini-vci w/techstream, or dealership/independent mechanic?
8. How was it determined that you needed to replace 3 new batteries?

Video about 12v battery location/replacement:

 

I would say yes.

 

I think there is a terminology issue here. You must be talking about the 12V auxiliary battery. Three hybrid batteries would have set you back about $7,500, not $600.

Assuming I am correct, any sort of maintenance charger such as the one you already bought is fine to keep your 12V battery topped off. Most of the chargers sold today are "smart" and will not overcharge the battery. They will sense when the battery is full and go into trickle mode. I use Battery Tender brand on my motorcycle during winter storage and it will probably work fine on the Prius, but I think the one you bought is totally fine and safe, provided it's one of those "smart" ones. Most of them are these days.

If your hybrid battery is dying because you do not use the car a lot, then that's a whole different issue and a whole different set of equipment and methods is involved.

 

This has got to be the 12 volt battery. Our situation, the car will often sit for 2~3 days. I keep it hooked up to a CTEK Multi US 4.3. It's fine to hook it up, let it run through a charge regimen, and then remain connected, as long as the car is idle. There's various other similar chargers. You're looking for something around 4 amp, and a "smart charger".

If you're likely to be hooking it up frequently, a quick-connect is good to install. My charger came with one; I've wired it into the under-hood fuse box, so I just need to make a corded connection, no alligator clips. I still need to pop the hood, but that's relatively easy, and I can then set the hood ajar, with the wire running under.

You could also wire a quick connect to run out through the front grill, but it's less secure. There is an inline fuse, but it's more vulnerable, someone might try to short it out or something, not sure.

 

welcome to priuschat.

 

We use the CTEK Multi 7002 7 amp and have a green-yellow-red LED charge state telltale/connector hard-wired to the 12V in the right rear cargo compartment.

 

Had to hunt a bit for this, and it's maybe overly cautious, but on page 502 of the Owner's Manual (at least in my pdf version), the max recommended charge rate is spec'd at 4.2 amps:



If you've got significantly higher and it's working, it's working. But shopping for a new charger, something to consider.

 

The CTEK 7002 produces 4.3A in the managed "Smart Charge" protocol, and up to 7A in open "Supply" mode (like a battery booster).

 

Ah, I saw that number, jumped to conclusion.

 

Verify in your manual, probably 4.2 amps, indicated on page 502. The operative word, what you want a "smart" charger, ie: one that can assess the battery, go through a charging regimen, tapering off to a maintenance charge.

If your current battery condition is really bad, it's not worth charging. A smart charger may let you know this. Research them online, a lot of times there'll be a pdf users manual available, you can read through it, see what it can and cannot do.

Most battery retailers these days have electronic load testers, to determine conclusively where your battery stands. There's DIY level versions, but for starters those retailers would be the simplest route.

You can charge at the jump point under the hood, or directly at the battery; either will work.

I'm happy with my CTEK multi US 4.3, also have an older 3.3, fine also. @Air_Boss 's 7002 also sounds like a good choice, believe it is 4.3 amps as well? Note, 4.3 is SLIGHTLY over 4.2, but I suspect Toyota's very conservative with this spec.

 

Yes. Doesn't hurt to try though. This is a snapshot from my CTEK 4.3 manual, saying before it starts the charging regimen, it assesses the battery determines IF if it's chargeable. That's the norm for smart chargers I think:




I'll attach the full manual.

\Still, if you're regularly having dying batteries, there may be some underlying issue, something using juice when the car's off, say an aftermarket alarm, dash cam that's not turned off, or just something defective.

This guy's expression when he cranks the car is priceless:

 

My basic approach would be to:
1. Disconnect the 12v from the cables. Were the cable connections to the battery loose?
2. Apply a battery charger with a voltage indicator for several hours directly to the disconnected 12v. Until the battery reads 13 volts.
3. Disconnect the charger. Let the battery sit for several hours. Retest voltage. It will sink a little but if good, not much.
4. Reconnect battery. Does the car now start?
5. Apply battery maintainer/reconditioner to the charging points under the hood to maintain voltage.
6. Exercise car once a week.

Some units can do all of these things recondition, charge, maintain. Those are usually the more expensive ones.