Tim Dressel
New Member
- Joined
- Sep 22, 2021
- Messages
- 3
A $649.00CAD 100ah lifepo4 battery with charger is scary.@smoothJoey I've been thinking along the same lines but going a bit simpler (no Pi req'd) with an all in one LiFePO4 battery with built in bms and charger.
Not as modular/flexible as your setup but should do the same thing. Would appreciate your thoughts.
Are you planning an online or offline ups?@smoothJoey I've been thinking along the same lines but going a bit simpler (no Pi req'd) with an all in one LiFePO4 battery with built in bms and charger.
Not as modular/flexible as your setup but should do the same thing. Would appreciate your thoughts.
ok scream power is just a hilarious name.A $649.00CAD 100ah lifepo4 battery with charger is scary.
Considering the name is "Scream Power", that's nightmare fuel.
UPDATE: Maybe I'm just out of touch. There are lots of batteries in that price range on amazon.ca.
awesome!! way to dodge the old chemistry!Yeah, I should have updated the thread. I adapted one of Will's milk crate builds, leaving out the solar charge controller, and using 4x 100Ah packs from batteryhookup.com. Way overkill for the power capacity, but it's working well so far.
@danb35 which charger did you use? how is it working for you? any reliability problems from Drok?Yeah, I should have updated the thread. I adapted one of Will's milk crate builds, leaving out the solar charge controller, and using 4x 100Ah packs from batteryhookup.com. Way overkill for the power capacity, but it's working well so far.
I made my own double conversion ups.
Mine runs a base load of ~256 watts.
It can if needed deliver 1500 watts but in reality the load never exceeds ~512 watts.
At 512 watts my worst case scenario battery backup is 7 hours.
For the base load its 14 hours.
Mine charges off of mains power.
It discharges to ~50% DOD and then charges to full because lifepo4 batteries don't like to be kept full.
Even worse is to expose them to continual voltage stress above their full resting voltage.
Are you looking to build something?
@Supervstech Actually, Most UPS < 1000watts float at 13.6v which is perfect for LifePo4 . Check Will´s Video on Battleborn Factory Tour.Lifepo4 is not suited for the charge parameters most ups boxes use.
The issue is LFP needs to set at around 50% charge during storage. It doesn't like to rest full.
Most ups boxes float 14.8 for SLA.
A better plan would be a hybrid inverter configured for battery priority, where it runs off battery, switches to ac for charging then repeats.
Eaton makes 2 different versions of LiFePO4 rackmount UPS. Here is one version:Lifepo4 is not suited for the charge parameters most ups boxes use.
The issue is LFP needs to set at around 50% charge during storage. It doesn't like to rest full.
Most ups boxes float 14.8 for SLA.
A better plan would be a hybrid inverter configured for battery priority, where it runs off battery, switches to ac for charging then repeats.
That is perfect for an in use lfp setup.@Supervstech Actually, Most UPS < 1000watts float at 13.6v which is perfect for LifePo4 . Check Will´s Video on Battleborn Factory Tour.
I have tested >20 UPS for Float Voltages.
Yes, inverter chargers, or all in ones can be. So it’s best to get one of these to draw from the battery daily… not use a UPS designed for SLA and putting LFP instead.To make an ups requires little more than a decently configurable inverter/charger and a battery.
LFP batteries like to be cycled but many inverter/chargers can be configured to do manage this.
Actually, Lifepo4 are drop in replacements for SLA.Yes, inverter chargers, or all in ones can be. So it’s best to get one of these to draw from the battery daily… not use a UPS designed for SLA and putting LFP instead.
So you´r saying that if you follow Battleborn´s recomendation to float their LFP batteries at 13.6V. The batteries will FAIL?That is perfect for an in use lfp setup.
But if left plugged in, and only drawing from the bank when power is out, 13.6 will keep an LFP at 100% SOC and will degrade the cells in a short time.
For LFP to work in a UPS scenario, there would need to be a 3 fold charge profile, 14.4V then 13.2 float then 12.8 standby.
Otherwise the cells will be held at 100%SOC and fail.
Check any battery source… LFP is not designed to be stored at 100%Actually, Lifepo4 are drop in replacements for SLA.
So you´r saying that if you follow Battleborn´s recomendation to float their LFP batteries at 13.6V. The batteries will FAIL?
Well, that is a pretty awfull blanket statement right there.Check any battery source… LFP is not designed to be stored at 100%
It is designed to be cycled.
Fully charging LFP and NOT draining it is bad for the battery.
LFP would work perfectly in the ups, the problem comes when you use it AS a UPS, keeping it plugged in always floating fully charged, and never draining it.
"Float Voltage13.6 will keep an LFP at 100% SOC and will degrade the cells in a short time.