Charging the Lifelines questions

Mexico Mike

Are you in Michoacan or Vizcaino Desert/Biosphere?

Reed and Elaine

Mex wrote:
Presently I am at 111F inside the house and maybe its 121F or so outside. ... The locals are suffering. They aren't used to heat like this. The bad part is the humidity - 52% and it is clouding up. There's going to be some deaths in this pueblo over this and I feel sad for them. No one including me has home insulation.

Mex ... you need air conditioning ... pure and simple.

.... or next best - a rock wall with water running over it like the one in Scotty's Castle. Don't delay.

Mexico Wanderer

Two questions:

1. Where are you that it is 46°C?

2. Why are you staying there?

Time to go north or up in elevation. It was 105° F at son's place in Fort Collins a few years ago so went up to 10,400' just north of Rocky Mountain National Park and it was max of 75° F during the day and 38° F at night.

Reed and Elaine

Reed, now -that- would work. Presently I am at 111F inside the house and maybe its 121F or so outside. The Lifeline is disconnected. The locals are suffering. They aren't used to heat like this. The bad part is the humidity - 52% and it is clouding up. There's going to be some deaths in this pueblo over this and I feel sad for them. No one including me has home insulation.

Extremes like this are totally outside the control realm of battery converters or tenders. At 120F charging, even maintenance should altogether cease. The acid is just too corrosive. In Las Penas I would be in the ocean. Here it is 68 degrees with horrendous undertow. Obviously the breath of air is onshore. Oops we just gained another degree. We have another hour to go before it peaks. Past 111F it gets uncomfortable for me. 124F is the record here in the Vizcaino Desert. Just threw water on my stainless tubing hand rail outside and it steamed off. But the tomatoes, bananas and papaya are digging these temps!

I had a thread asking about AGM's and extreme temps before I bought the Lifelines. I wanted the info before I laid out the cash.

The fan on the MegaWatt is already making a horrid noise. Good thing I have some laying around.

I don't think the 45 C is hard and fast. Other blogs state 50 C (122 F) It doesn't mean much more than possible slight degradation. Chris Dunphy was probably up to 140 F in his battery compartment.

Whatta bummer. It got to 46c here three days ago. When I fire up a generator using $3.80 gallon fuel to recharge a deeply depleted battery in warm temperartures the last thing I want to do is trickle charge a huge bank. I suspect that high temperature limit is for the core of the lithium battery and with the risk of overheating and fire, that worries me. Lithium is appropriate for some folks it seems but not for others. I seem to be on the "excluded" list. I would like to take this opportunity to thank you for clarifying this for me. I'll have to make do with flooded and AGM.

Mexico Wanderer

Standard LFP will discharge at fairly low temperatures. The minimum values given in literature for discharge at low temperature are between –20°C and -30°C. The problem is in charging at high C charge rates and there the minimum temperature is 0°C. It is quite likely that the low C charging rates of solar in the morning may mitigate this. We left our rig at son's place in mountains of northern NM for the last two years when we flew to Central America one winter and South America for another winter and it got down to –30°C. Inverter was off (it has a parasitic draw of about 100 W) and so the battery suite was never discharged more than -300 W (-3% of total charge) so that charge rates would have been extremely low.


It is possible to heat the battery storage area with heating pads and/or incandescent light bulbs (30 W or so). We have done this to keep the main luggage are (basement) warm on cold nights to prevent the pipes from freezing. This kept the baggage area to upper 30's on nights that got down to –23°C. We have sufficient battery storage to do this.

The other worry is high temperatures and the limits are 45°C for charge and 60°C for discharge. Cris Dunphy of Technomadia blog has written candidly with problems of possible overheating when they were parked on tarmac in Phoenix during the summer for several weeks. The LFP battery bank was in a non vented compartment with the inverter and the temperatures could have been fairly high. We leave the battery/inverter compartment (8' x 2' x 3' or so) open when using inverter to run air conditioner. We plan to eventually install a couple of 12 V receptacles for 12 V fans (12 W) for increased circulation.The same receptacles will work for incandescent lamps.

Have installed a remote thermometer in the battery (otherwise known as a $15 Walmart inside/outdoor thermometer) to monitor the temperatures in the bay. The highest we have measured was 32°C when it was 34°C ambient.

Reed and Elaine

Here the temps range from 20 below to 100 or more above, I had to consider that in my choice.

Maybe I'll buy some used Teleco Li FePO4's some day, down in San Diego...