Switch to LIFePO4?
I have a trio of Rolls Surrette FS210 wet cell batteries that give me about 315 AH of usable capacity. My big concern is weight, the total is 400 lbs in my from compartment of the 5er, and I think tha...
Forum Discussion
So, here are some snippets of email exchange with the owner of the company producing these LIFePO4 batteries (Lynac Lithium). Your comments are appreciated. I'm leaning towards giving him a try, he's an electrical engineer (I checked his LinkedIn page) and seems pretty up front. Will ask for references. Looks like he started off by hand-building battery units for another business of his, got into the battery business and is now having manufacturing done in China...
Sorry for the late response, I was on the road yesterday.
I checked out the Samlex 3012 Inverter, it looks goods, with plenty of power and proper charge ranges. You will have to customize it's charging parameters for LiFePO4. I can help further with that down the road.
If you were to go with 2 x 300Ah batteries, each unit has a max current draw of 100A. The total max draw for them together is 200A. It is most certainly OK to draw up to 200A for short bursts. Basically it depends on the duration and frequency of current spikes to 150A (0.75C). The more the system is drawing above 0.5C(100A), the more capacity loss you will see over time. Microwave, toaster up to 150A would have negligible lasting effects, if any.
Now, 4 x 100Ah batteries - 400A max draw
6 x 100Ah batteries - 600A max draw
Easier install with the 300Ah's and far less hardware required, but you are sacrificing some top end current draw.
My reply:
Thanks for the info, would appreciate quote for both 2x 300 amp and 4x 100 amp. I am located in Quebec, postal code is XXXXXX
Wouldn’t .5C on 300 AH unit be 150? Why is there a difference for that unit vs the 100 AH?
The Samlex is a 12v unit, so I can’t put them in series. You’re saying that if they are paralleled then C would be drawn across both equally (presuming they are wiring correctly)? I’ve never seen a draw above 175 amps and that was for a couple of minutes.
A question I would have is why your pricing is significantly lower than other brands such as Battleborn or Relion. This is a significant investment and as I’m sure you can understand I’m a little hesitant with a lesser known or newer company, no offense!
His reply:
Sorry for the confusion. You have (C) rating correct. When wired parallel, you add the capacity of each battery to get the total battery bank capacity. I was speaking in terms of the max current that can be drawn. The max current draw from our 300Ah battery is 100A. The max draw from our 100Ah battery is 100A. When you wire them in parallel, you add the max current draw from each battery to get your total bank maximum current draw.
For comparison:
6 x 100Ah: Capacity = 600Ah, Max current = 600A
2 x 300Ah: Capacity = 600Ah, Max current = 200A
I have been using this technology in machines with my partner company (www.Lynac.com) for 2 years. I created the machine BMS fo them. We saw the need to serve the Canadian market as we became familiar with the technology. We JUST launched the website and have been slightly struggling to keep stock. The American market is overpriced in my opinion, they get away with it because demand is so high with limited options. I can say that Relion and Battleborn use basically the exact same technology s us and the cells are no different. Credibility is tough when you are starting out in this market. We are confident enough to offer a 3 year warranty and will continue to assist or repair if something were to go wrong thereafter.
Sorry for the late response, I was on the road yesterday.
I checked out the Samlex 3012 Inverter, it looks goods, with plenty of power and proper charge ranges. You will have to customize it's charging parameters for LiFePO4. I can help further with that down the road.
If you were to go with 2 x 300Ah batteries, each unit has a max current draw of 100A. The total max draw for them together is 200A. It is most certainly OK to draw up to 200A for short bursts. Basically it depends on the duration and frequency of current spikes to 150A (0.75C). The more the system is drawing above 0.5C(100A), the more capacity loss you will see over time. Microwave, toaster up to 150A would have negligible lasting effects, if any.
Now, 4 x 100Ah batteries - 400A max draw
6 x 100Ah batteries - 600A max draw
Easier install with the 300Ah's and far less hardware required, but you are sacrificing some top end current draw.
My reply:
Thanks for the info, would appreciate quote for both 2x 300 amp and 4x 100 amp. I am located in Quebec, postal code is XXXXXX
Wouldn’t .5C on 300 AH unit be 150? Why is there a difference for that unit vs the 100 AH?
The Samlex is a 12v unit, so I can’t put them in series. You’re saying that if they are paralleled then C would be drawn across both equally (presuming they are wiring correctly)? I’ve never seen a draw above 175 amps and that was for a couple of minutes.
A question I would have is why your pricing is significantly lower than other brands such as Battleborn or Relion. This is a significant investment and as I’m sure you can understand I’m a little hesitant with a lesser known or newer company, no offense!
His reply:
Sorry for the confusion. You have (C) rating correct. When wired parallel, you add the capacity of each battery to get the total battery bank capacity. I was speaking in terms of the max current that can be drawn. The max current draw from our 300Ah battery is 100A. The max draw from our 100Ah battery is 100A. When you wire them in parallel, you add the max current draw from each battery to get your total bank maximum current draw.
For comparison:
6 x 100Ah: Capacity = 600Ah, Max current = 600A
2 x 300Ah: Capacity = 600Ah, Max current = 200A
I have been using this technology in machines with my partner company (www.Lynac.com) for 2 years. I created the machine BMS fo them. We saw the need to serve the Canadian market as we became familiar with the technology. We JUST launched the website and have been slightly struggling to keep stock. The American market is overpriced in my opinion, they get away with it because demand is so high with limited options. I can say that Relion and Battleborn use basically the exact same technology s us and the cells are no different. Credibility is tough when you are starting out in this market. We are confident enough to offer a 3 year warranty and will continue to assist or repair if something were to go wrong thereafter.
