pianotuna wrote:
Hi Matt,
I did not misquote you deliberately.
You would have a hard job designing an LI battery pack for me as I need it to be good to -40. Heating the battery bank electrically would be a zero sum game, so until someone comes up with an LI chemistry that works at -40 without the need to be warmed they will not be useful to me. Propane heating would also be futile for my particular use pattern. (i.e. 3 months storage at temperatures that rarely climb above -20 C and that are as low as -40).
From what little I know of LI, they do not trickle charge too well. That eliminates small solar as a charging source. One person on the Forums does have 1400 watt of solar powering their RV with LI batteries, so it is possible. They don't cold weather RV.
It is moot, as I'll never have the funds for an LI installation.
My ideal system would be six two volt AGM's with a capacity of 800 to 1000 amp-hours. Recharging would be met by 1250 to 1500 watts of solar.
Don,
Is true that in Regina you don't even use the snow until it is at least a year old? ;)
You do have a problem, but even Lead/Acid (be they AGM or Flooded) do not do well at low temperature. (Trust me, I have been there.) An insulated battery compartment with a provision for forced cooling is about the only hope. All batteries generate heat when they are charged, if you can use that heat to get them to a better temperature for charging, you win. But Yes, that takes charging at a rate to make heat at all.
What I am waiting for is the hybrid car batteries to start to show up on the used market. I go to a couple of electric vehicle shows a year some are hobby shows and some are trade shows. I look at prices. I too am stuck with old technology for the foreseeable future.
Matt
