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Hylas Discussion / Re: LiFePO4 batteries
« Last post by snailor on November 30, 2020, 02:51:49 PM »We replaced our three 8D Lifelines with three Relion 8D LiFePO4s two years ago. We've kept our two Lifeline 4D AGMs for our starting/backup house bank. It was a little bumpy at first and it took me a while to zero in on something approaching optimal settings for all of our charging sources. I probably had the most trouble getting our Victron MPPT controller to cooperate followed by several rounds of adjustments to our Balmar MC-614 regulator. I also replaced our main charger/inverter with a Victron 2,000 watt model that's supposedly smart enough to deliver the right charging profile for lithium Batteries. We still use our other three chargers in parallel using their AGM settings and this seems to work just fine.
In our experience the lithium batteries work well with AGM settings but we've managed to optimize settings in equipment having that capability. I think Relion recommends a charging voltage for their 8D of around 14.2V but I think its okay to go up as high as 14.6V - similar to AGMs. However they also recommend holding charging current to 50A. Since we have two banks 1X8D (300AH) and 2x8D (600AH) we runup to as much as 80-90 amps and see no distress in either bank. We wish we had room to even up the two banks with 2X8D each but alas the first bank only has physical space for 1 8D and 1 4D.
Our main house alternator is a Balmar 210 amp controlled by the MC-614 regulator equipped with both alternator and battery temperature sensing. We monitor the two banks through two Xantrex LinkPROs and a Victron monitor as well. These have alarms set should the battery or alternator temperatures rise above the recommended 60 degree C limit. At the moment we've limited the charge levels using the internal settings (which escape me at the moment). I think we can go higher but I sometimes worry how hot the alternator getting hot in warm weather while charging at full capacity. In any case we find we can run the batteries down to 50% and be back up to near capacity in a couple of hours of motoring. We occasionally run them even lower than 50 percent but old habits die hard and I think even ReLion does indicate the cycle life is shortened by deeper discharges. Nevertheless, these things are supposed to go 5-6,000 cycles through deep discharge so they'll probably outlast me.
One other thing I did was to install an echo charger from one of the house batteries over to the AGM bank to provide a load to the alternator at all times - even if the internal BMS in the lithiums disconnects them from the alternator. This is a safety measure to prevent blowing the diodes out of the alternator if that ever happens. It also keeps the starting bank fully charged. So far we've never seen high charging temperatures or signs of overcharging with our system. Overall we're pretty satisfied with the performance of the new batteries. One thing I like is these lithiums can discharge pretty far without experiencing much of a voltage drop. They also have low internal resistance and therefore charge much faster that we were able to achieve with the AGMs.
If I had any advice it might be to stick with one manufacturer for as much of the system as possible. It would make the programming and integration simpler and easier to follow.
In our experience the lithium batteries work well with AGM settings but we've managed to optimize settings in equipment having that capability. I think Relion recommends a charging voltage for their 8D of around 14.2V but I think its okay to go up as high as 14.6V - similar to AGMs. However they also recommend holding charging current to 50A. Since we have two banks 1X8D (300AH) and 2x8D (600AH) we runup to as much as 80-90 amps and see no distress in either bank. We wish we had room to even up the two banks with 2X8D each but alas the first bank only has physical space for 1 8D and 1 4D.
Our main house alternator is a Balmar 210 amp controlled by the MC-614 regulator equipped with both alternator and battery temperature sensing. We monitor the two banks through two Xantrex LinkPROs and a Victron monitor as well. These have alarms set should the battery or alternator temperatures rise above the recommended 60 degree C limit. At the moment we've limited the charge levels using the internal settings (which escape me at the moment). I think we can go higher but I sometimes worry how hot the alternator getting hot in warm weather while charging at full capacity. In any case we find we can run the batteries down to 50% and be back up to near capacity in a couple of hours of motoring. We occasionally run them even lower than 50 percent but old habits die hard and I think even ReLion does indicate the cycle life is shortened by deeper discharges. Nevertheless, these things are supposed to go 5-6,000 cycles through deep discharge so they'll probably outlast me.
One other thing I did was to install an echo charger from one of the house batteries over to the AGM bank to provide a load to the alternator at all times - even if the internal BMS in the lithiums disconnects them from the alternator. This is a safety measure to prevent blowing the diodes out of the alternator if that ever happens. It also keeps the starting bank fully charged. So far we've never seen high charging temperatures or signs of overcharging with our system. Overall we're pretty satisfied with the performance of the new batteries. One thing I like is these lithiums can discharge pretty far without experiencing much of a voltage drop. They also have low internal resistance and therefore charge much faster that we were able to achieve with the AGMs.
If I had any advice it might be to stick with one manufacturer for as much of the system as possible. It would make the programming and integration simpler and easier to follow.