LiFePO4 battery sizes that fit in 200 drawer wings (1 Viewer)

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My SOK battery order just got cancelled so now it’s back to the drawing board. Any particular reason to get the 18amp victron vs the 30amp?
Less load on the alternator?
Or split the difference (almost) and go 25A with RedArc ;) . I'd read some RedArc article about the low and slow approach to charging. They basically just said anything under 200Ah is best suited with around 25A charger. That being said, I think that mainly applies to AGM where lithium can handle a much faster charge if you want it. I've seen several builds that went 40A with a 100Ah battery
 

radman

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Or split the difference (almost) and go 25A with RedArc ;) . I'd read some RedArc article about the low and slow approach to charging. They basically just said anything under 200Ah is best suited with around 25A charger. That being said, I think that mainly applies to AGM where lithium can handle a much faster charge if you want it. I've seen several builds that went 40A with a 100Ah battery

redarc seems to be to go-to around here, but victron offers Bluetooth and much more granular programming.
 
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redarc seems to be to go-to around here, but victron offers Bluetooth and much more granular programming.
Yeah I also spoke with an electrical engineer last week that said Victron's solar charging algorithm is much better than the RedArc. I went with RedArc but I am going with the Victron 712 monitor/shunt combo, so I that does have the awesome Victron Bluetooth and app features. Or another option is just the Victron smart shunt if you want the Bluetooth but don't need the physical monitor, that's what @sdnative I said he had
 

Hants

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Yeah I also spoke with an electrical engineer last week that said Victron's solar charging algorithm is much better than the RedArc. I went with RedArc but I am going with the Victron 712 monitor/shunt combo, so I that does have the awesome Victron Bluetooth and app features. Or another option is just the Victron smart shunt if you want the Bluetooth but don't need the physical monitor, that's what @sdnative I said he had

I’ve heard similar from someone who does extensive testing of solar panels and solar charge controllers... the RedArc solar charger is significantly behind the leading solar chargers.
 

sdnative

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Or split the difference (almost) and go 25A with RedArc ;) . I'd read some RedArc article about the low and slow approach to charging. They basically just said anything under 200Ah is best suited with around 25A charger. That being said, I think that mainly applies to AGM where lithium can handle a much faster charge if you want it. I've seen several builds that went 40A with a 100Ah battery

Most if not all LFP batteries can handle 0.5C charge (50A into a 100Ah battery), some can handle more. For a 100Ah LFP battery, any of the chargers with LFP specific profiles up to 50A should be fine, just depends on how fast you want to charge. Of course double check the spec sheet on your specific battery. I am not aware of any minimum required charge rate for LFP batteries.
 

Hants

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Or split the difference (almost) and go 25A with RedArc ;) . I'd read some RedArc article about the low and slow approach to charging. They basically just said anything under 200Ah is best suited with around 25A charger. That being said, I think that mainly applies to AGM where lithium can handle a much faster charge if you want it. I've seen several builds that went 40A with a 100Ah battery

The Relion RB75 I have, specs say recommended charge rate is 3.7A-37.5A, and max charge current is 75A. LiFePo batteries all have internal charge controllers, AFAIK. This means that they likely have hard limits to specs like charge rates (for instance, I would be quite surprised if you could charge at >75A, or discharge at higher than the specified limit).

Regarding the earlier conversation about charging temps, from 14F to -4F they recommend significantly lower charge rates.

I have had AGM batteries in multiple vehicles. Due to the low internal resistance, they have very high charge and discharge rates, and no built-in charge controller to limit.

If you look at the charge profile on any of these batteries, only “bulk” is at high amperage. Things like cable length and diameter requirements play into the recommended charge rate, in addition to the practicalities of how long (wall time) it takes to materially charge your battery bank.
 

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