Ohmmu LFP battery in a Gen 5 Prius ?

1. No, I did not get the Bluetooth version. (I can never get Bluetooth anything to ever work for me, but that's just me). I can see voltage when I'm in the car as I have two voltmeters, one that measures at the terminals of the battery and one that measures at the converter. I can see a voltage difference when the battery is low and charging, indicating there is loss in the cable between the two.
2. No device to monitor on phone. Just visual of the voltmeters. If it were to disconnect it would reset my fuel mileage and other such measurements at instrument cluster, which it hasn't done that so far. So far it stays at around 13V or better. I should keep better track of the lowest it goes when used alone with my 100W shortwave radio. I do remember it dropping down to close to 12V (maybe even 11.8V IIRC) under load, but didn't keep track of the exact number. I don't think I've ever drained it down below 12.5V not under load.
   
3. I do not have a plug-in hybrid. So I never charge off of AC power.

 

Thinking about this, it is a fire hazard to install an LFP 12-V battery. First, it cannot be mounted securely due to the incorrect size, and then, lithium-ion batteries (including LFP-cathode cells) have a tendency to catch fire in crashes to begin with.

 

Perhaps all or mostly true. But the stock 12V SLA is not a good battery for my purposes (amateur radio). So, I either deal with a sub-par battery, give up my hobby, or just have to take that risk. Others will have different situations that may or may not justify an LFP battery.

 

It that a loaded question?

There might be a smokin gun, riddled though out this forum. A fire, no I haven't heard of one, but I'm not looking all that hard either.

 

LFP (LiFePO) is considered a safe battery that doesn't catch on fire, or is at least very difficult to catch on fire. They can be overcharged, overdischarged, overcurrent, shorted, overheated, punctured, crushed, etc. and still don't catch on fire except maybe rarely. Now is it as safe as or safer than lead acid? I'll let you be the judge.

 

So this morning was the first time the LiFePO4 battery had shut itself off due to extreme cold. I could not start the car. On a side point, I had a very hard time unlocking the driver's door with the key from inside the key fob. After that it was easy to get into the trunk/hood and jump start the car with it's original 12V LA battery.

I may either just get a LiFePO4 charger (Li-Time recommends their 20A version) and leave it charging all night or just switch to the LA battery and, well, I'd still need to charge the LiFePO4 battery if I'm going to be doing any all-day ham radio. Either that or I need to start shielding all the electrical in the car so I can just sit and ham radio with the car running. The engine running in particular raises the noise floor tremendously. Sometimes I wish I still had my old NA mechanically injected VW diesel with a noise floor increase of practically zero.

 

I wish I had an actual thermometer on the battery. But the car was outside, and it was around -15°F/-26°C outside a good portion of the night, and I had gotten home early the day before so from around 3pm until 8am it had sat in the cold without the self-warming function, and the spec sheet says that the battery shuts off completely at -4°F-20°C. So my guess is the battery itself got below -4°F/-20°C.

After running the car a couple hours (I did drive around town doing errands) it seems to have self-heated enough to fully activate the battery again at 50°F/10°C. The battery voltage when I turned off the car was 13.3V, and the spec sheet says it won't start charging until it self-warms up to 50°F/10°C (only discharges between -4°F/-20°C and 50°F/10°C).

 

Yes, that's about right. So far it seems to be working as intended. Li-Time does sell Bluetooth batteries now, as well as more sizes, so maybe in the future I would try one of those.

On the other hand this battery from SodiumHybrid.com claims to work down to -40°F/-40°C without any need for BMS shutoff. It is 36Ah, as compared to 50Ah (25Ah usable) on the stock battery for my Avalon hybrid, and compared to the large 100Ah LFP battery I have on it now. That would be another battery I would consider after asking others how theirs fare.

 

Yikes. Well, that's deal killer for me if I was ever considering an LFP. If the battery shuts off at -4F, it'd mean I'd be stranded maybe 20 or 30 times a winter.

 

Mind you we've been getting down to between -10 and -30 °F every night for the past 2 weeks with it never getting above freezing during the day and finally this happened.

Still, it is a risk, so I understand you. The good thing is that while the car is running the self-heating battery heater seems to keep everything working fine and the battery holds that heat for hours after turning off the car.

Personally I'm going to try an LFP charger so it will activate the self-heater all night long. I plug in a block heater every night anyway, so adding another device on the car isn't a problem for me.

 

I've seen -52 °F here. I got a self heating battery. It only heats when charging. So if the car is off, it can only stay on until -4 °F. But if ran often it heats up to 50 °F IIRC.

 

Last night we got home at around 9:00pm. So the car was off until this morning and so far the battery didn't self shut down. It also wasn't as cold last night, I saw 0 °F on the thermometer this morning.

 

I had a question about the brand of heated LFP until I looked at some earlier posts. Than I searched a bit more elsewhere and found Will Prowse ( DIY Solar Power forum ) ( I'd already seen a bunch of his youtubes ) which get a bit advanced for my current solar DIY level. I've also seen some battleborn heated LFP videos and prices for their products which prompted my curiosity on this subject.
Thanks for helping me up my game another step as to what's currently available, otherwise I'd still be a few years behind from where I was before reading this thread.