LiFePo4 Batteries Issues and Diagnosis

[koko64]

I'll check em out. Some local comp for Shorai. Cheers

[Howie]

Forgot,  https://earthxbatteries.com/earthx-now-australian-distributor-jetline-aviation

[koko64]

I notice the yellow alternator to regulator wires and the main fuse wires are only luke warm when using a healthy Shorai battery "receptive" (for want of a better term) to showing 14+ V while the bike was running. Those same wires get hot when a weak Shorai battery "unreceptive" to taking more than 13.7V is used. My test involved using two identical Shorai LFX18 batteries and the healthier battery resulted in sitting at about 13.8-14V at idle and 14.3V at higher revs with the headlight on. The healthy battery is the burned shop battery that survived a major bike fire and still cranks hi comp motors. . The weak battery sat at high 12s at idle and low 13s at revs.

I tested for voltage drop from battery to frame to motor to regulator earth point. All good. It has a new Electrosport single phase reg, the headlight is bright. The difference in heat to the touch of the wires mentioned was substantial between the strong and weak batteries. The headlight is strong with either battery and the only difference is the heat in the aforementioned wires and voltage at the battery terminals while the motor is running. This speaks to me of internal battery resistance in the weak battery that would not take the higher voltage. It's standing voltage was about 13.2V while the strong battery's sitting voltage was about 14.2V.  It appears to mimic the resistance of sulphated lead acid batteries. It is hard to understand the chemical behaviour of LiFePo4 batteries in regard to internal resistance compared to the old technology, but tht's what it looks like.

What do you reckon Howie? Am I on the right track?

[koko64]

Just an update. I tested the weak battery after a restoration routine to check my findings. When I go through the resurrection routine on the weak battery and stretch it back up into the 14+V range, the wires are only luke warm like when using the strong battery. It's as if the equivalent of a lead acid desulphication process for LiFePo4 batteries has reduced the internal resistance, as the running voltages were the same as the strong battery and the wires did not get hot.

That is my finding but I do not have the theoretical framework for explaning the chemical process, just my observations.

[NAKID]

The last thing I'd spend my money on is a lithium battery.

That's just me.

I'm a curmudgeon...

seriously, the technology isn't worth it IMO. Special chargers, different regulator requirements...poor life...yada yada yada.

Gimme a good old lead acid battery. You can almost see the electrons flowing.

Poor life? Maybe in the first couple of iterations, but Shorai now offers a lifetime warranty with their LiFePO4 batteries. And the charger is only ~$85 versus ~$40 for a good tender. Not a huge expense IMO.

[koko64]

That's great to hear, backing the product. How conditional is the warranty?

A buddy of mine (electrical engineer) has suggested that although the weak battery has "come back", it may be too damaged and revert to the lowest denominator over time as far as resting voltage is concerned. We'll see over the next few days as I check it's resting voltage and how it goes under the bike's charging system.

[ducpainter]

Poor life? Maybe in the first couple of iterations, but Shorai now offers a lifetime warranty with their LiFePO4 batteries. And the charger is only ~$85 versus ~$40 for a good tender. Not a huge expense IMO.

So, other than a 'lifetime warranty', which I rarely trust, what's the advantage?

[koko64]

Imo, only light weight, packaging due to small size, non toxic and low discharge rates (if no parasitic loss). A quality Yuasa AGM is cheaper and more reliable than most LiFePo4 technology available imo. I may try EarthX batteries as they claim to have built in protection against the very things that void warranties.
My Hyper had a Yuasa AGM, rock solid.

[ducpainter]

Imo, only light weight, packaging due to small size, non toxic and low discharge rates (if no parasitic loss). A quality Yuasa AGM is cheaper and more reliable than most LiFePo4 technology available imo. I may try EarthX batteries as they claim to have built in protection against the very things that void warranties.
My Hyper had a Yuasa AGM, rock solid.

Like I said...a Lith battery would be the last thing I'd spend my money on.

Not enough benefit.

Everyone else do what you want...you will anyway.

[koko64]

A buddy of mine (electrical engineer) has suggested that although the weak battery has "come back", it may be too damaged and revert to the lowest denominator over time as far as resting voltage is concerned. We'll see over the next few days as I check it's resting voltage and how it goes under the bike's charging system.

Also have a Shorai LFX18 out of an MTS1100 I am "bringing back". Emailed the distributor here but have not heard back yet. I think a good test of battery health for the Shorai is testing what the resting voltage settles down to after a few days and whether the Shorai charger senses over discharge and is happy to conduct a quick top up and balance without throwing an alarm code. If the resting charge settles to 14.2-3V and the battery can hold that charge, the battery cranks well and the Shorai specific maintenance unit doesnt throw a fit and does it's thing quickly, and, the battery takes a good 14V off the bikes alternator/reg combination with no symptoms, then the battery is ok. That's a lot of "ifs".

The weak battery out of my M900 came back well to sit at 14.3V and let the Shorai charger do its thing without complaint so I'm hopeful.

This begs the question Howie recently put to me; should we run such batteries without an on board balancing/maintenance system and expect a bikes charging system to balance all the cells?

[ducpainter]

You created your own mess...

live with it.

[koko64]

I've changed the heading so that some of the stuff learned about these newfangled LiFePo4 batteries is emphasised.

[Howie]

I predict a great thread ahead!

[koko64]

 
This new technology is becoming more common (even oem in some cases), so it's the future. It's worth collating member's contributions to develop the forum community's understanding of the technology for maintenance, diagnosis and trouble shooting.

[NAKID]

So, other than a 'lifetime warranty', which I rarely trust, what's the advantage?

Like others have said it's mainly weight and packaging benefits. I think the lifetime warranty is a huge plus. We actually just warrantied one that was overly discharged and wouldn't come back. Totally the customer's fault, but Shorai replaced it anyway.