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Re: Lithium Iron Phosphate Battery

Posted: Sun Oct 09, 2022 5:50 pm
by stitch2k1
Dave W. wrote: Fri Oct 07, 2022 9:06 pm Thanks for the tip! The NOCO batteries on Summits website look like a good deal for the money.
I might give them a try. I have a NOCO jump box.
My only real concern to update is potential battery fire issues. I need to update the FE I carry in the S2. Cheaper than Hagerty.

Edit: https://no.co/nlp20

Looks pretty good. 600A is plenty for me in FL. 14.6v is required, so a charging system update is required. All in all, it might be an upgrade I save for the street-track project, where it would DEFINITELY help. My goal is to build a 924S at 2,500lbs and still be streetable with (some of) an interior.

Re: Lithium Iron Phosphate Battery

Posted: Thu Oct 20, 2022 8:57 am
by Ajay213
I realize this is a little older now, but some random thoughts;

- A factory battery is like 40-50 Amp/Hr in size, so keep that in mind when comparing to a cheaper motorcycle sized battery, the one linked above is a 7Amp/HR battery. A 944 doesn't have a heavy electrical load, but a 7A battery is still very small, so if you ever have a problem starting your car, a 7A battery will have some troubles pretty quickly. On the flip side, if your car is healthy, you can lose a LOT of weight with one sized that way (Porsche does that with the GT cars and I think it's optional on some others?). LI batteries have VERY high discharge rates, hence a very small battery can start a bigger engine (or has a higher CCA type rating), but it just won't have a lot of capacity.

- The BMS is important, you can buy a 'raw' 12v Li battery pretty cheap these days, but without the BMS you risk turning it into a paper weight or creating a bon-fire. They aren't nearly as fragile as people think, but they don't do well with over and under charges. A company like Antigravity puts a bit more work on that side (which is also why they are priced the way they are).

- Li batteries and heat, they tend to have problems once the actual battery temp goes over 130F, so it should be ok in a 944 factory location. But you don't want them to get too cold, below freezing temps is just as bad. A good BMS will cut power under either of those.

-Li gets a bad reputation with regards to fires. All of the Boeing/laptops/phones/scooters/etc that we all heard about were not using LiFEPO type batteries, which are considerably safer than the technologies used in those devices. LiFEPO is used in EV's and the majority of those fires come from physical damage to the battery pack and/or a failure during the charging side and then the HUGE amount of energy stored in them (or the HUGE amount of energy that is being put into them). We are a bit sensitive to LI battery safety because of the stories, but LOT's of vehicles have burned to the ground because of lead acid/AGM battery failures, one needs to be aware of the dangers of any battery that has that much energy in it.

Hope it helps.

Re: Lithium Iron Phosphate Battery

Posted: Tue Mar 14, 2023 9:13 am
by Dave W.
Update: I purchased a NOCO NLP30 for my daily driver last week. I'm happy with it. It weighs 5 pounds, has 700CCA and starts the engine as if it's really 700CCA. I was worried that the 8ah capacity might be too low, even though I rarely use electrical power when the engine is off, but it hasn't been an issue yet. The recommended charging rate of 14.5 volts has not been an issue either. I watched my voltmeter while driving and it took a few days to reach a fully charged state while doing 45-minute-long commutes. I checked the temperature after driving and felt no heat or warmth. The price was about the same as a replacement lead/acid battery, so I think we've reached the turning point where lithium batteries should become the norm. Saving 35 pounds is a nice bonus, too.

Re: Lithium Iron Phosphate Battery

Posted: Tue Mar 14, 2023 10:08 am
by Tom
Dave W. wrote: Tue Mar 14, 2023 9:13 am Update: I purchased a NOCO NLP30 for my daily driver last week. I'm happy with it. It weighs 5 pounds, has 700CCA and starts the engine as if it's really 700CCA. I was worried that the 8ah capacity might be too low, even though I rarely use electrical power when the engine is off, but it hasn't been an issue yet. The recommended charging rate of 14.5 volts has not been an issue either. I watched my voltmeter while driving and it took a few days to reach a fully charged state while doing 45-minute-long commutes. I checked the temperature after driving and felt no heat or warmth. The price was about the same as a replacement lead/acid battery, so I think we've reached the turning point where lithium batteries should become the norm. Saving 35 pounds is a nice bonus, too.
Awesome. Might need to check one out. How did you secure it in place?

Re: Lithium Iron Phosphate Battery

Posted: Tue Mar 14, 2023 1:21 pm
by j1nx3d
Another risk of sounding silly, can two smaller lifepo4 batteries like the Noco 600 be connected in parallel to boost performance? Even with 2 batteries there's still a significant weight saving.

Re: Lithium Iron Phosphate Battery

Posted: Tue Mar 14, 2023 7:11 pm
by Dave W.
j1nx3d wrote: Tue Mar 14, 2023 1:21 pm Another risk of sounding silly, can two smaller lifepo4 batteries like the Noco 600 be connected in parallel to boost performance? Even with 2 batteries there's still a significant weight saving.
I thought about that too. The problem is you need to find a way to balance the charge between the two batteries. If the resistance is different, and it usually is, then one battery gets more charge. The battery that gets less charge also wears down a little faster, which makes it worse as time goes on.

Re: Lithium Iron Phosphate Battery

Posted: Tue Mar 14, 2023 7:54 pm
by Dave W.
Tom wrote: Tue Mar 14, 2023 10:08 am
Dave W. wrote: Tue Mar 14, 2023 9:13 am Update: I purchased a NOCO NLP30 for my daily driver last week. I'm happy with it. It weighs 5 pounds, has 700CCA and starts the engine as if it's really 700CCA. I was worried that the 8ah capacity might be too low, even though I rarely use electrical power when the engine is off, but it hasn't been an issue yet. The recommended charging rate of 14.5 volts has not been an issue either. I watched my voltmeter while driving and it took a few days to reach a fully charged state while doing 45-minute-long commutes. I checked the temperature after driving and felt no heat or warmth. The price was about the same as a replacement lead/acid battery, so I think we've reached the turning point where lithium batteries should become the norm. Saving 35 pounds is a nice bonus, too.
Awesome. Might need to check one out. How did you secure it in place?
Hi Tom,
I just used a generic battery hold down bracket from the local O'Reilly. Since you mentioned it, I did a quick search and found this beauty with nearly perfect dimensions.

https://www.ebay.com/itm/364172057518?h ... R9jx2rLcYQ

Re: Lithium Iron Phosphate Battery

Posted: Fri Apr 07, 2023 11:04 am
by cp99
Dave W. wrote: Tue Mar 14, 2023 9:13 am Update: I purchased a NOCO NLP30 for my daily driver last week. I'm happy with it. It weighs 5 pounds, has 700CCA and starts the engine as if it's really 700CCA. I was worried that the 8ah capacity might be too low, even though I rarely use electrical power when the engine is off, but it hasn't been an issue yet. The recommended charging rate of 14.5 volts has not been an issue either. I watched my voltmeter while driving and it took a few days to reach a fully charged state while doing 45-minute-long commutes. I checked the temperature after driving and felt no heat or warmth. The price was about the same as a replacement lead/acid battery, so I think we've reached the turning point where lithium batteries should become the norm. Saving 35 pounds is a nice bonus, too.
It turns out I need a new battery or fill up the cells with water, which I don't know how effective that will be.

So can you provide an update on your NLP30 experience? My car has the stock alternator, so I want to see how yours is running before I buy the NLP30. Have the cold starts been ok? Any issues driving at night with the headlights on? Did you purchase a new charger that works with LI batteries? What lugs/clamps did you use to connect the cables to the battery?

Thanks!

Re: Lithium Iron Phosphate Battery

Posted: Fri Apr 07, 2023 11:11 am
by Zirconocene
No affiliation, but these look pretty nice, though are more expensive than the eBay part which was shared: https://www.rennline.com/porsche/944/el ... ount-kits/

Cheers

Re: Lithium Iron Phosphate Battery

Posted: Fri Apr 07, 2023 12:37 pm
by Dave W.
cp99 wrote: Fri Apr 07, 2023 11:04 am
Dave W. wrote: Tue Mar 14, 2023 9:13 am Update: I purchased a NOCO NLP30 for my daily driver last week. I'm happy with it. It weighs 5 pounds, has 700CCA and starts the engine as if it's really 700CCA. I was worried that the 8ah capacity might be too low, even though I rarely use electrical power when the engine is off, but it hasn't been an issue yet. The recommended charging rate of 14.5 volts has not been an issue either. I watched my voltmeter while driving and it took a few days to reach a fully charged state while doing 45-minute-long commutes. I checked the temperature after driving and felt no heat or warmth. The price was about the same as a replacement lead/acid battery, so I think we've reached the turning point where lithium batteries should become the norm. Saving 35 pounds is a nice bonus, too.
It turns out I need a new battery or fill up the cells with water, which I don't know how effective that will be.

So can you provide an update on your NLP30 experience? My car has the stock alternator, so I want to see how yours is running before I buy the NLP30. Have the cold starts been ok? Any issues driving at night with the headlights on? Did you purchase a new charger that works with LI batteries? What lugs/clamps did you use to connect the cables to the battery?

Thanks!
I put the NOCO battery in my daily driver, so I don't need to use a charger. My voltmeter typically shows 13.8 to 14.0 while driving so I don't believe it's necessary to charge at the recommended 14.5V. IMHO optimum charging is at 14.5V but 14.0 seems to work just fine.
Cold starts are great. The engine spins quickly with no sign of struggle. I also have newish battery cables between battery, starter and alternator, and a newish starter.
Driving with all electrical loads on, such as headlights, wipers, fan and brake lights, the voltmeter shows 13.6V. Typical night driving with just lights on is 13.8V.
BTW I just bought another NLP30 for my other car. Prices on eBay/Amazon seem to be coming down.