ohthetrees
New Member
- Joined
- Jun 28, 2021
- Messages
- 76
Hi, I'm installing a LiFePo4 system with an REC BMS. Im trying to figure out how to control the charger, a Mastervolt Mastercharge 12-100 100 amp. The charger I have works well, but it doesn't have BMS start and stop signaling, so the only way I can think of to turn it off and on is with an SSR.
If I haven't gone terribly wrong so far, now I need to decide whether to interrupt the AC input, or the DC output. I can't just interrupt the low voltage on-off switch, because this model uses a momentary switch that I must hold down for a few seconds to turn on and off.
SSR on AC input:
Lower amperage might mean lower cost SSR? Better for charger and battery to have input power disappear than having output load disappear? Would this be a good one? SSRT-240D25 Could the REC BMS drive it directly?
SSR on DC output:
Need a bigger, more expensive SSR for 100a current. Good ones readily available from Blue Sea, like the 7701. Would it be bad for the charger to suddenly disconnect under load?
So what do you think? Relay on input AC, or output DC? Or am I missing another option?
If I haven't gone terribly wrong so far, now I need to decide whether to interrupt the AC input, or the DC output. I can't just interrupt the low voltage on-off switch, because this model uses a momentary switch that I must hold down for a few seconds to turn on and off.
SSR on AC input:
Lower amperage might mean lower cost SSR? Better for charger and battery to have input power disappear than having output load disappear? Would this be a good one? SSRT-240D25 Could the REC BMS drive it directly?
SSR on DC output:
Need a bigger, more expensive SSR for 100a current. Good ones readily available from Blue Sea, like the 7701. Would it be bad for the charger to suddenly disconnect under load?
So what do you think? Relay on input AC, or output DC? Or am I missing another option?