LiFePo4 battery users

[sternwake]

Sounds like you got quite the capable electrical system Kat. Sometimes I think about having the ability to run a 15 amp table saw from my Van, or other larger power requirment power tools, but am woefully lacking in PSW inverter to do so, and even engine idling the battery would see 50 to 80 amps of load and alternator would get too hot too quick maxed out like that. I'd have to rig up some sort of cold air intake to the back of the alternator to do that with any regulararity. Obviously more battery and a juicepacked Lifepo4 could power more of the load that the alternator cannot.

Yesterday I spliced up another 45 amp anderson powerpole on 10AWG into the 8awg wires already feeding my MPPT solar controller. I had been hooking my 100 watt portable panel directly to any handy 12v powerpole I have located in many convenient places, but once the portable panel itself could make enough amperage on its own to hold absorption voltage, soon it would exceed it ad could overvolt the battery and my system if I was not there to stop that from occurring.

Also direct connecting a panel I would lose some watts from it by not removing it from battery voltage dragging it down, the whole MPPT advantage being bypassed. So it is nice having this extra MPPT input available.

With lead acid I do worry about achieving absorption voltage early enough in the day so that there is enough time in the afternoon to hold absorption voltage, as long as required to get full. and that time has doubled at deep cycle 1000, compared to #400. That is the whole key with getting good life deep cycling lead acid, and it would be nice to not need to worry about achieving full, like one can with Lifepo4. I could likely get away with less solar without the need to achieve absorption voltage before 1pM just to keep lead acid happy enough. I'd only need the portable panel on select occassions, rather than as a necessity just to keep lead acid happy.

I was going to mount the 100 watt sunpower flex panel to my roof, but would have to modify it and my roof to get an acceptable installation, and the panel by itself stores nicely on the shelf over the drivers seat, So I decided against hard mounting it.

I also could not have achieved such good lifespan from lead acid without the ability to plug in or at least deliberatley driving early in the morning, much more often.

My Northstar AGM requires the occassional high amp recharge to full from a well depleted state. Too much low and slow solar only recharges, even to full, have it behaving poorly in as little as 6 deep cycles. I can and do regularly feed my 90Ah agm-27 65 plug in amps and my alternator can go as high as 106. My roof solar can do 12 to 13 june 21 at noon.

If Lifepo4 does not care whether it gets low and slow, or lots of amperage from a capable source, there is yet another advantage of that chemistry over lead acid.

I think Charge rate is well misunderstood huge grey area with lead acid, especially when solar is involved and one wants to second guess the recommended rates provided by manufacturere who are generally assuming an overnight charge via a plug in charging source.

Personal experience says not to worry about exceding the recommended charge rates in vandweller applications emplong lead acid batteries. My previous flooded marine group 31 regularly saw large amperages and behaved better after receiving them. The Nannies will say no more than 10 to 13 amps per 100Ah of lead acid capacity. I say no less than 20 for a plug in charging source and mo is bettah.

I've never seen much in the way of recommended minimum and max charge rate for Lifepo4 and how that affects the total KWH figures one could expect from the battery.