Hi everybody,
GIven that my previous efforts to grid charge my battery only got me a month of trouble-free service and that my voltage Taps show one tap that is extremely different from the rest I'm going to try to see if I can get a junkyard battery pack grid charge it and see what kind of shape I can get it into.
The plan is to do everything I can with grid charging this extra battery pack to get it into good shape and then take the sticks which act the most like the sticks that are in my current pack (most of which are still functioning well) and replace the 1 - 6 which are not quite as good as the rest.
I had one voltage tap which was Far Below the rest and to which were just a little outside of the recommended tolerance

I have an offer for one pack for $300 that I could drive and get but the junkyard is reporting that it's been sitting since April. I've read conflicting information whether this would be a good buy or not. I seem to recall hybrid Automotive saying that even if a battery sits a for that long it could still be brought back to life with enough patient grid charging but I think I've also read on this forum that this is not the case.

I'm not looking to spend much on this, 350 (including costs to go and get it) is about my limit.

Thoughts on any of this?

 

Check the taps on the pack. If you have a handful of decent taps > 14.4, you may have several useful sticks.

Look for evidence of prior disassembly.

Look for the sticker - Panasonic EV Energy vs. Primearth EV Energy. The Primearth packs tend to have less consistent quality, but aren't necessarily bad.

If the pack contains yellow sticks, they are likely original Honda sticks. If they are not yellow, best to stay away.

Sitting does not hurt a healthy pack. Sitting can help deteriorated sticks self-discharge to the point that they shed their voltage depression and improve in other areas.

$300 sounds like a fair price for what you've described. If I was in your situation, I would likely purchase it assuming a few good taps and yellow sticks.

I recommend that you fully recondition the pack outside the car - 3 cycles - before attempting to build a good pack from two.

 

yeah I'm definitely going to do three good Cycles and then take measurements on that drain and compare it to the data from when I was cycling my pack

the only part that really scared me was it it's been sitting for 4 months plus. Sadly my pack is not a Panasonic

 

So it's Primearth? That may mean nothing. Given that it's known that someone has been in your pack, it's hard to conclude anything from that.

The 4 month sit is NOT a concern if the sticks are yellow.

 

was there any significant differences between 03 and 05? This pack is from 03

 

Stick-wise, No. IIRC, sometime in mid-04, they eliminated the PTC circuit, so you will have to deal with that, but it's as simple as either cutting a wire or adding a resistor.

I hold the belief that the older ones are better given similar mileage/use conditions.

This is based on the assumption that as production continues, they are in a non-stop effort to reduce cost/increase production. Often these are attained by incremental compromises in quality/performance. If a manufacturer can lower cost by 5% and decrease longevity/warranty rates by <0.5%, you know they are going to do it.

I have found with significant consistency that 04-06 Prius modules are better than 07+, and I've evaluated 2,828 of them.

 

pack at 70volts, all taps between 6.8 and 7.15

 

Could be good or bad... hard to say. When they sit for extended times and self-discharge to low levels, they tend to improve.


If all the sticks are yellow, it may be worth it anyway.


I would definitely recommend 3X full reconditioning cycles.

 

well We're Off to the Races.
the voltage jumped from 70 to 100 and a matter of seconds and I do mean jump not climb. And it's been climbing steadily and quickly up to about mid 150s and I was hanging out at 163.

so when these things self-discharge what exactly is going on there? the electrons are going from the one side where there's more of them to the side where there's less of them, or are they hanging out but losing the voltage pressure? (I know it's not 100% one or the other....but in general)

I made the mistake of trying to test the voltage taps a few minutes ago you can pretty much watch them climbing by tenths of a whole every couple seconds... so not a meaningful measurement.

a half hour later I did a measurement and I got 1-tap that's .1 volts below the rest but other than that they're all within .03 which again I understand we're charging so that's going to be suspect it's up to 165 already.

since this is no longer really the subject of the original post I think I'm going to start another one to not clutter The Forum

 

The junk yard had the whole back seat module. They had sold the square shiney box that the volt taps connector plugs into ( BCM right? ) but the larger module to the other side was still in there.
foolishly thinking they may cut me a break if I let them keep some of it i said I only needed the battery pack, and that the other part was used to convert the 3 phases of A.C. from the motor into DC. As we drove off, I watched them pitch the rest of the parts into the scrap metal bin.

any guess how much I gave away there?