Hello all- I have been handed a new RELiON RB50 battery. So I’m wondering if I can use it in my setup (and honestly I like learning about new things so I’d love it get some feedback and opinions and suggestions). Sorry it’s a long read...
My boat currently has single interstate deep cycle srm-24 on switch posistion 1, and an srm-24 in parallel with an srm-27 on switch position 2. This is how the boat came (she is new to me this year but a 1981 build).
I have 3 small incandescent cabin lights, one 12v fan, gx-2200 vhs/ais receiver, a jabsco electric head, and use navionics on a Samsung rugged 2 waterproof tablet (android version of navionics does correct text on course up view). So my power needs are little.
Boat usually goes for day sails, from a mooring, engine typically is used to leave/enter the mooring field and occasional pickups and supply from dock. I do the occasional overnight with kids on the hook.
The yanmar is the 3gym I believe (it’s the 30 hp with freshwater cooling but I can never remember the model number). It has the stock hitachi alternator (no external regulator). I am comfortable using the conventionally wired 1/2/b/off as is.
My gripe-
The boat has a ton of battery, all mounted far out to starboard along with the 12g fuel tank and 20 gal holding tank. The location of the battery area can not be changed. Ive only got a 20gal water tank to port, so even with the lead ballast all to port she still lists ever so slightly. Not a big deal but yes I notice.
So my thought is is- can I replace the #2 batteries with one of these relions? They have a built in BMS.
Since the #1 battery is used only as a starter, it think it is basically full all the time except due to self discharge. I could start on posistion 1, then switch to both once running. The RELiON is a 12.8 nominal voltage battery that wants 14.2 V - 14.6 V charge voltage. I believe that’s compatible with the lead?
The LiFePO4 would suck up power super fast, but the BMS will take the battery offline once it is full. Perhaps the alternator theoretically/hopefully wouldn't blow its diodes as the lead acid battery is still connected. I’m not sure if this offline action of the BMS is like a hard stop or not.
Could the regulator on the hitachi be relied on to protect the alternator from the hungry LiFePO4? I’m not sure.
My hope-
Once engine is off switch to #2. I now have a 15lb 50amp that can be taken to a low soc without damage, and won’t be damaged from sitting around with a low charge. I have less weight and the start battery will be happy as it’s only starting. I could probably install a monitor for the lifep04 as you can’t tell what’s going on from voltage (right?).
Anyhow it’s a thought- love to hear alternate ideas and feedback. I’m reasonably sure there’s no way it could be this easy or more people would have this set up.
My boat currently has single interstate deep cycle srm-24 on switch posistion 1, and an srm-24 in parallel with an srm-27 on switch position 2. This is how the boat came (she is new to me this year but a 1981 build).
I have 3 small incandescent cabin lights, one 12v fan, gx-2200 vhs/ais receiver, a jabsco electric head, and use navionics on a Samsung rugged 2 waterproof tablet (android version of navionics does correct text on course up view). So my power needs are little.
Boat usually goes for day sails, from a mooring, engine typically is used to leave/enter the mooring field and occasional pickups and supply from dock. I do the occasional overnight with kids on the hook.
The yanmar is the 3gym I believe (it’s the 30 hp with freshwater cooling but I can never remember the model number). It has the stock hitachi alternator (no external regulator). I am comfortable using the conventionally wired 1/2/b/off as is.
My gripe-
The boat has a ton of battery, all mounted far out to starboard along with the 12g fuel tank and 20 gal holding tank. The location of the battery area can not be changed. Ive only got a 20gal water tank to port, so even with the lead ballast all to port she still lists ever so slightly. Not a big deal but yes I notice.
So my thought is is- can I replace the #2 batteries with one of these relions? They have a built in BMS.
Since the #1 battery is used only as a starter, it think it is basically full all the time except due to self discharge. I could start on posistion 1, then switch to both once running. The RELiON is a 12.8 nominal voltage battery that wants 14.2 V - 14.6 V charge voltage. I believe that’s compatible with the lead?
The LiFePO4 would suck up power super fast, but the BMS will take the battery offline once it is full. Perhaps the alternator theoretically/hopefully wouldn't blow its diodes as the lead acid battery is still connected. I’m not sure if this offline action of the BMS is like a hard stop or not.
Could the regulator on the hitachi be relied on to protect the alternator from the hungry LiFePO4? I’m not sure.
My hope-
Once engine is off switch to #2. I now have a 15lb 50amp that can be taken to a low soc without damage, and won’t be damaged from sitting around with a low charge. I have less weight and the start battery will be happy as it’s only starting. I could probably install a monitor for the lifep04 as you can’t tell what’s going on from voltage (right?).
Anyhow it’s a thought- love to hear alternate ideas and feedback. I’m reasonably sure there’s no way it could be this easy or more people would have this set up.