BMS
- Thread starter jtjgl
- Start date
That very much depends on your usage.
What are you planning on supplying power to? How many amps, etc.
Max draw at anytime would be around 40amps.
If that is your peak draw at 24v, then JBD or Overkill solar BMS are some of the most reliable (just not high amps).
Thanks. I was thinking about the overkill solar 100amp. Just so I'm correct, the BMS rating refers to how many max amps you can draw, it has nothing to do with the battery AH.
That is correct
labeeman
Solar Enthusiast
Yep you can connect a 60 amp BMS to a 1000 ah battery.
MisterSandals
Participation Medalist
And how many amps you can charge thru the BMS.
Yep I forgot that part auctully
Thanks
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
24V/280AH/7.168kWh, can support up to 280A Discharge & 140A Charge.
24V pulling 250A = 6000W.
250A is typically the MAX recommended pull from a battery bank.
Constant Draw is the normal running of whatever "usual" items not the high loads like pumps or fridge every 20 minutes etc... If you are running an AC for hours on end, that is a "constant draw" as such.
So your "Maximums" are
250A Fuse or 300A if concerned for Surge potential.
BMS Max should not be more than 250A either but can be up to 300A for surge handling extra buffer. If needed.
A FET BMS to support 250A should be rated no less than 20% Above the minimum required. It is ALWAYS best to under-rate the BMS for safety margin.
If Relay/Contactor controlling BMS, the same applies to the Relays/Contactors, allow for a margin above the max potential loads you expect.
A SmartBMS can often be programmed to limit In/Out Amps and cutoff thresholds which can be used to further "safety" your equipment.
"Best BMS" is a tough Q, because it depends on application usage & Discharge/Charge capacities to be handled. Without a lot more info such is hard to suggest. For BMS' it is usually best t think of "worst case scenario" and plan for the maximums possible. The main reason for that is your lifestyle & items are one way today but things change along with needs etc... Also, you only want to Buy Once and not have to upgrade if you undershot and ended up with Magic Smoke. I have yet to meet anyone who likes to toss hard earned cash away for any reason, especially if they under judged and created the problem by going too small or too cheap.
Two examples to ponder on.
1200W Panasonic Inverter MIcrowave @ Full Power will draw 74A from 24V system
1000W Coffee Maker will draw 50A+/- from a 24V system. Get a coffee maker with Thermal Carafe and get rid of the horrible enegry wasting warmer that burns it.
Hope it helps, Good Luck
24V pulling 250A = 6000W.
250A is typically the MAX recommended pull from a battery bank.
Constant Draw is the normal running of whatever "usual" items not the high loads like pumps or fridge every 20 minutes etc... If you are running an AC for hours on end, that is a "constant draw" as such.
So your "Maximums" are
250A Fuse or 300A if concerned for Surge potential.
BMS Max should not be more than 250A either but can be up to 300A for surge handling extra buffer. If needed.
A FET BMS to support 250A should be rated no less than 20% Above the minimum required. It is ALWAYS best to under-rate the BMS for safety margin.
If Relay/Contactor controlling BMS, the same applies to the Relays/Contactors, allow for a margin above the max potential loads you expect.
A SmartBMS can often be programmed to limit In/Out Amps and cutoff thresholds which can be used to further "safety" your equipment.
"Best BMS" is a tough Q, because it depends on application usage & Discharge/Charge capacities to be handled. Without a lot more info such is hard to suggest. For BMS' it is usually best t think of "worst case scenario" and plan for the maximums possible. The main reason for that is your lifestyle & items are one way today but things change along with needs etc... Also, you only want to Buy Once and not have to upgrade if you undershot and ended up with Magic Smoke. I have yet to meet anyone who likes to toss hard earned cash away for any reason, especially if they under judged and created the problem by going too small or too cheap.
Two examples to ponder on.
1200W Panasonic Inverter MIcrowave @ Full Power will draw 74A from 24V system
1000W Coffee Maker will draw 50A+/- from a 24V system. Get a coffee maker with Thermal Carafe and get rid of the horrible enegry wasting warmer that burns it.
Hope it helps, Good Luck
Yes, and don't forget that many BMS will only let you charge half of what they will let you draw. Not all, but many of the FET based BMSs have this limitation. Just something to keep in mind (like you said).
Overkill (and the JBD it is based on) are pretty solid, and accurately rated. In other words, if they say 100 amps, you can pretty much draw 100 amps for 8 hours, many other brands are not accurately rated. As Steve mentioned, you need to order at least a 200 amp (preferably 250 amp) Daly to get 150 amps continuous. If you need more than 200 amps continuous, I would recommend a contactor or relay based BMS (and over rate the relay/contactor).
