My LFP Charger Overcharges, Any Way to Cutoff Charging at Say 14.2V?

DIY
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1

OK, so I want to charge my two LFP batteries from my powerful and expensive charger, which puts out 10Amps x 2 channels (perfect for my needs), because replacing it is pretty expensive, and it works very well. Only problem is that it likes to charge LFPs to 14.5V for an hour and I think that’s a bit much, and it’s not configurable.

I have found from watching my Victron 75/15 MPPT that my battery connected to it, charges to full most of the time in only 20 minutes at 14.2Volts.

So I would like to install a device on the positive of each of my charger’s positive lines, that cuts off charging at 14.2 volts. I think it’s good enough. And they can be topped up from solar if needed anyway. I just want the charger to provide quick fill up bulk charge.

The Victron Energy Smart BatteryProtect 12/24-Volt 65 amp looks interesting, IF I could make it work in reverse IE instead of undervolt protection, it could be used for OVERvolt protection.

I wish there were battery chargers that were as configurable as Victron MPPTs! But they all seem designed for their own preferences, hard coded.

Any suggestions? I would think there would be a simple device to just cut off at 14.2V but I can’t seem to find it in Google/Amazon etc.

Thanks in advance :slight_smile:

2

Every Victron charger is configurable like the Victron MPPTs.

The overvoltage protection of the BatteryProtect is not configurable, but maybe you can use the “load output” of the MPPT to switch the BP on/off via it’s remote contact.

3

Well that’s some very interesting information.

Now I’m considering putting both batteries in parallel and getting a single outlet Blue Smart IP22 charger. 20A for 2x 160Ah batteries which should top up one overnight on shore power. It’s a simpler system. And it’s configurable. And not as expensive as the old charger it replaces. Nice :slight_smile:

Now I need a low voltage alarm. Because my autopilot is on one battery, and that’s critical hardware on the boat and I don’t want to lose that because I ran the inverter or fridge too long. Although a shut off no longer makes sense with this system as they will be in parallel, I will need a battery monitor/alarm. I don’t suppose you have any suggestions for that one?

4

BMV? SmartShunt?

Just take a look through the Victron product portfolio: