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Need recommendations for LiFePO4 engine starting battery

LarryJForman

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Joined
Apr 7, 2021
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I have been making some progress with my Ultravan RV solar and Lion battery system. I decided to purchase a dedicated engine starting battery now (and for engine starting reliability) and keep looking for the four 280a DIY cells when I can find a reliable (read as dependable) supplier who can sell Grade A properly packaged and without damage four cells. I need something over about 500 CCA and am looking for small and light and around $300. I really like the Australian FPV-POWER 12V 25AH LIFEPO4 SUPERCAP COMBO for $300 plus shipping cost. I love the fact that it can crank 1900 CCA, and is WAY beyond what I need for that big Olds Toronado engine and it is just under 15 lbs. I have not yet checked what the shipping cost and delivery time will be. I would like to get something like that here in CA if possible and maybe someone here can recommend an alternative. I went ahead and purchased the Noco Genius GenPro 10X1 and that would perfectly charge that FPV dedicated engine starting battery, which I would also use for powering the engine when under way as well as the electric fans to cool the two large radiators. Once I get a lithium engine starting battery I will likely get a DC to DC converted to recharge that battery when under way. Note: I also purchased a Victron 500 Amp SmartShunt so I can monitor how much amperage my engine takes to start and run as well as the electric cooling fans so I don't over tax the engine starting and running battery.

I used my Will recommended battery capacity tester and verified my fears were well founded that my main Optima Yellow Top AGM spec'd at 55AH and 750 CCA is really now at only about 8AH(!) Ouch! So I will need to see if it will be covered under the warranty or do something until I can build a 280a or 272a 12 volt house battery. Note: that weak Optima AGM has still been able to start that big engine when charged only by my now 200 watt solar system. But I need to move forward on getting a dedicated engine starting and running battery as well as my ultimate house battery.

So if anyone has recommendations for alternatives to the Australian FPV Supercap hybrid battery I am all ears.
 
I have been making some progress with my Ultravan RV solar and Lion battery system. I decided to purchase a dedicated engine starting battery now (and for engine starting reliability) and keep looking for the four 280a DIY cells when I can find a reliable (read as dependable) supplier who can sell Grade A properly packaged and without damage four cells. I need something over about 500 CCA and am looking for small and light and around $300. I really like the Australian FPV-POWER 12V 25AH LIFEPO4 SUPERCAP COMBO for $300 plus shipping cost. I love the fact that it can crank 1900 CCA, and is WAY beyond what I need for that big Olds Toronado engine and it is just under 15 lbs. I have not yet checked what the shipping cost and delivery time will be. I would like to get something like that here in CA if possible and maybe someone here can recommend an alternative. I went ahead and purchased the Noco Genius GenPro 10X1 and that would perfectly charge that FPV dedicated engine starting battery, which I would also use for powering the engine when under way as well as the electric fans to cool the two large radiators. Once I get a lithium engine starting battery I will likely get a DC to DC converted to recharge that battery when under way. Note: I also purchased a Victron 500 Amp SmartShunt so I can monitor how much amperage my engine takes to start and run as well as the electric cooling fans so I don't over tax the engine starting and running battery.

I used my Will recommended battery capacity tester and verified my fears were well founded that my main Optima Yellow Top AGM spec'd at 55AH and 750 CCA is really now at only about 8AH(!) Ouch! So I will need to see if it will be covered under the warranty or do something until I can build a 280a or 272a 12 volt house battery. Note: that weak Optima AGM has still been able to start that big engine when charged only by my now 200 watt solar system. But I need to move forward on getting a dedicated engine starting and running battery as well as my ultimate house battery.

So if anyone has recommendations for alternatives to the Australian FPV Supercap hybrid battery I am all ears.
Correction: that 8AH AGM capacity was only to the 50% 12.3V setting so it is really about 16AH, but still near death.
 
I had an extra Valence XP battery from a project. The 138 amp/hour version. It is the same size as a Group 27 car battery. I dropped it in a boat and it works great.
 
OK, I was not familiar with the Valence XP 138AH battery. The specs say it is good for 300 Amps for 30 seconds. That is getting very close to my needs. I run about 400 amps for 10 seconds or so as measured by a 1000A clamp meter. I think I need to now install my Victron 500 Amp SmartShunt and take some measurements to verify my real cranking current. I also need to measure the voltage when doing that since the amps will peak if the battery voltage sags. With that tired Optima AGM, I might be getting artifically higher cranking amps and a stronger battery might see lower cranking amps. While that Olds 455 is a low compression engine, it is still a huge engine. Many thanks for pointing this out to me.
 
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