Alternator, regulator, battery? 2009 696

[koko64]

Yes I was wondering about that. Considering how tight a voltage range Lith batteries need you want 14-14.3. Since they are in reality 13V batteries, they're getting low at 13V. I would be curious to see what readings you got with the oem reg. I would also ask Shorai what they think about running the oem reg.

[metroplex]

Shorai claims the OEM rec/reg is fine, but that seems to be the case for a lot of LFP manufacturers. I asked them specifically about float voltage, and they said anything 13.1 VDC would be fine. I tested my Deltran Battery Tender Jr. to float it at 13.66 VDC and they said it was fine, but for max safety they recommended that I just charge it up infrequently versus leaving it on indefinitely like a normal lead-acid.

I measured the open circuit voltage at the terminals for a few weeks without the battery being connected. It would rest somewhere around 13.06-13.16 VDC.

[koko64]

I tend to agree with a periodic charge over an ongoing trickle. I think to leave a charger on maintenance requires a high quality, intelligent charger. I have a Tecmate Optimate Lithium charger and also an Optimate AGM, lead acid, Gel, etc version. They conduct diagnostics, monitoring and save functions automatically. Ive got the Shorai charger too (and two Ducati chargers among others). I agree with others here that cheap trickle chargers can kill batteries.

[koko64]

Would be an interesting exercise to see the readings with the oem reg. How's the wiring and connector from the alternator?

[metroplex]

From experience the Battery Tenders are the only maintainers I'd trust leaving them on indefinitely on my lead-acid batteries. I've been buying and using them since 2006 and have them on each battery I don't use regularly. But LFP is a different animal altogether, and I know not to leave any of them constantly charged (whether it is a smartphone, tablet, etc...)

The wiring and connectors looked fine.

I had the OEM R/R working just before I had issues with the Yuasa. It was at 13.6 VDC idling, 3-bars on the temp gauge. But this was on the instrument cluster and not at the battery terminals.

[koko64]

I have a mate who leaves his car battery on tender literally for years (he works overseas). He never had a problem, but I can't do that for more than a night once or twice each week. I clearly have trust issues.

[metroplex]

I have a mate who leaves his car battery on tender literally for years (he works overseas). He never had a problem, but I can't do that for more than a night once or twice each week. I clearly have trust issues.

For lead-acid, I use the Battery Tender and leave them on whenever I am not operating the vehicle. I've had batteries hooked up for years. The Battery Tender brand never failed me.

For Lithium, I'm using the Battery Tender Jr in LFP mode but I am hesitant to leave it on indefinitely.

I just read the Optimate manual and it says it floats at 13.6 VDC and then rests for 30 minutes. Every charger I've used for Lead-Acid that does that, has resulted in boiling over the lead-acid battery or causing it to fail. I am not saying Optimate will cause the Lithium batteries to fail, but I've had bad experiences with lead-acid chargers/maintainers that do that. The Tender for lead-acid will float at 13.2 VDC at 50mA-150mA indefinitely which seems to fine for the lead-acid batteries.

[metroplex]

Here's an update:

I measured 2.2 Ohms coil to coil to coil for the stator
During the initial cold start with the regulator disconnected, I measured roughly 17-18VAC across the stator coils at low idle (not touching the fast idle lever)
Once the RPMs kicked up to 2000-3000 RPM, I saw 41-42 VAC. I didn't rev it further.

I put everything back together, including re-organizing the 15 miles of wire that Rick's provides with their regulator, and saw 13.6 VDC from the instrument cluster but once I kicked up the RPMs to 3000-4000 RPM, I saw 14.1-14.2 VDC.

I didn't have an opportunity to put my multimeter across the terminals to see the actual reading while idling, I should have time tomorrow.

[Howie]

Did you check for voltage drop in the charging circuit?

[metroplex]

Did you check for voltage drop in the charging circuit?

From where to where?

[Howie]

From voltage regulator output to battery positive and battery negative to engine will give you total voltage drop for the system.  Since you did the cables I wouldn't worry about the negative side.  You should have less than .5 volts

  is a how to for a car.  Since the car has an internal regulator, or, if new enough, controlled by the ECU he goes from alternator output to battery.

Back to your readings.  Your Shorai battery will be happy as long as the charging rate is higher than 12.86 volts and your maximum for a full charge should be between 14.2 and 14.6 volts your numbers are pretty good, though you should check with a real  multimeter for accuracy.  At that, even good multimeters are accurate within 2%.  Yes, your Shorai is technically fully charged at 14.4, but you will not notice the fraction of 1%.

[metroplex]

So I got an opportunity to do some testing today.

Ran the multimeter on the battery terminal and kept an eye on the instrument panel voltage display as well. At times there is a 0.3 VDC discrepancy but most of the time they were within 0.05 VDC

When I first fired her up, the display would fluctuate from 13.6 then rise up as high as 14.2
On my multimeter, it basically stayed at 13.95 VDC. If it fluctuated, it was down to as low as 13.93 up to 13.96 mainly when I used the turn signals, and hit the brakes to induce some current draw. I'm running a LED H7 headlight bulb, which I am sure helped cut down on some current draw. The halogen H7 was like a rotisserie oven light.

I noticed the Rick's MOSFET Lithium regulator fins got as high as 160F when my display showed 3 bars (IR thermometer showed heads were around 255F, oil filter was 208F, so oil is fully warmed up). I'll have to check with them to see if that's normal/safe, as I haven't thought to check the stock regulator.

Someone here wanted to know what happens at 3000 RPM, so I checked it at various RPMs from 1300 RPM idle, up to 3150 RPM. The digital display would be at 14.0V with my multimeter at 13.95 VDC.