'06 FEH, 292,000 miles. Time to start thinking about an HV battery.

Here's what I want to know - Any ideas on the impact of time on these batteries vs mileage?

Yeah the SOC is abnormal occasionally. Low SOC once in a while after a weekend. It ran a regeneration/calibration cycle a month ago and another last week...

I'm not ready to give up on it, but need to be ready. This is my daily driver!

 

I have personally seen a 2007 Toyota Prius that went 256K miles in the Phoenix area. No cell failed, but a module leaked creating a HV path to chassis ground, which disabled the car. When the pack was reconditioned, the 27 remaining modules measured > 85% rated capacity.

If a Prius pack can do that in the hell that is Phoenix, I'm confident that the same can be done with one of the most reliable NiMH packs ever made (primarily from robust cooling system).

I would be willing to bet that reconditioning your battery on the PACK level, could restore the pack to near-new capacity UNLESS you are in very hilly terrain, and the battery has sustained permanent cycle damage.

Unfortunately, there are no commercial products available, but I have done DIY with success - at least in restoring a pack that discharged to 1V/cell. A $50 LED PSU is all you need to get > 400V to the pack, but it does require opening the battery cover and disconnecting a few things.

It could be discharged with 3X 110V incandescent light bulbs in series.

Alternatively, since you have the '06, I believe you could use the HV jumpstarter to improve pack balance.

 

I'm game. Unless it has a generator and points it's just magic to me, I'm an old school wrench.

But I know how to follow directions pretty good and can research to fill in the holes.

Any links?

 

This thread describes accessing the pack and where to attach the leads for the charger/discharger:

https://www.greenhybrid.com/forums/f...ry-jump-31056/

NOTE: THOSE ATTACH POINTS CARRY FULL PACK VOLTAGE WHEN THE SAFETY DISCONNECT IS IN. IT COULD KILL YOU.

Supplement for this exercise:

During charging lay a box fan on top of the cells with it blowing down through them.

Use the safety disconnect as a master on/off switch for both charging and discharging.

Discharger is just 3 cheap light sockets in series.

Currents are low, so 18awg wire is way more than sufficient.

Charge to peak voltage for 8 hours (voltage does not increase for 8 hours), not to exceed 25 hours.
Discharge with highest wattage incandescent bulbs you can find to 300V
Let bulbs cool and replace with 60W bulbs.
Discharge to 250V
Let bulbs cool and replace with 25-40W appliance bulbs.
Discharge to 200V
Charge to peak voltage for 8 hours (voltage does not increase for 8 hours), not to exceed 25 hours.
Discharge with highest wattage incandescent bulbs you can find to 300V
Let bulbs cool and replace with 60W bulbs.
Discharge to 250V
Let bulbs cool and replace with 25-40W appliance bulbs.
Discharge to 125V
Charge to peak voltage for 8 hours (voltage does not increase for 8 hours), not to exceed 25 hours.
Discharge with highest wattage incandescent bulbs you can find to 300V
Let bulbs cool and replace with 60W bulbs.
Discharge to 250V
Let bulbs cool and replace with 25-40W appliance bulbs.
Discharge to 125V
Charge to peak voltage for 8 hours (voltage does not increase for 8 hours), not to exceed 25 hours.

If the pack exceeds 90°F at any time, discontinue charge.

The last charge may be cut short after the LATER of 2 hours of grid charging or 313V.

 

Note also that Hybrid Automotive is working on an option for the FEH. They might be willing to work with you on developing it.

 

What sort of option?

 

Like every other product they have for other vehicles. Chargers, harnesses, smart dischargers, value dischargers.

 

S Keith:

Wow, thanks. I'm reading and jotting down parts!

Considering the long of tooth these hybrids are becoming should this not be a STICKY?

(yes it probably should)

Thank you!

 

Here's an update.

The FEH did another serious regen-cycle while SWMBO was driving to a neighbours (we live in the boonies ~15 miles one way). When I fired it up to go to town for provisions the Scanguage read SOC at 3.9%. Yeah I know!

Since then it has maintained between 48% to 53% SOC even through the rest of Christmas Holidays with lots of down time days and little bleeding off while parked over the weekends. Weird but it's like the good ol' days again.

Can it make it to 300,000? Doesn't seem to want to give up!

 

Sounds good.

You've always got that HV jump starter. I did some tests with mine. Tidbits:

It pulls 23A off the 12V.
Based on a nominal power relationship (23A*12V = 276W. 276W @300V = 0.92A). The 8 minutes of charging only puts about 123mAh into the battery.
Best to do it while connected to a 10A 12V battery charger.