Hi For 100 to 120 AH at 13.4V you will pay in the $900 to $1000 range (delivered) for the RV batteries with built in BMS. Capacity / price / current sale deal vary a bit manufacturer to manufacturer. Warranty also varies from <1 year to 10 years …..
Bob > On Mar 8, 2019, at 2:32 PM, jimlux <[email protected]> wrote: > > On 3/8/19 5:38 AM, Bob kb8tq wrote: >> Hi >> If you are headed into a “cost is no object” sort of battery backup bank for >> the lab / shelter / cave >> there are some interesting options out there. The RV world is very slowly >> waking up to the fact that >> big heavy lead acid batteries may not be ideal. For a ghastly amount of >> money, you can now get >> 12V 100AH “drop in” (no they are not drop in) Lithiums with fully integrated >> BMS systems in them. >> They *appear* to be safe and come with cute things like 10 year warranties . >> Be aware that you >> can buy a nice 5065 on eBay for what a couple of them will set you back ….. > > I've used the A123 7Ah "brick" LiFePO4 that replace the standard Lead Acid - > they weigh a LOT less, and cost a LOT more ($100 vs <$10) - They're pretty > nifty devices. As you note internal battery management, built in (easily > replaceable) 30A fuse, etc. > > They weigh about 850g (vs 2.6 kg) and work well at low temperatures (-20C) > > One peculiarity is that if you discharge them below minimum voltage, they > cutoff and put out nothing. You have to put a charging voltage on them to > turn them back on. This fouls up some "smart" battery chargers which use > the "discharged" battery voltage to tell them that there's a battery > connected. So we always had our smart chargers for day to day use, but had a > couple wall wart trickle chargers around to turn the battery back on. > > 100 Ah would set you back well over a kilobuck. But, you would be able to > lift it without you going over the OSHA 55lb/25kg "one person lift" limit. > > > > >> In return for your massive cash outlay, you get a battery that does not >> outgas or have the need >> to be watered along with the plants. It has a much flatter discharge voltage >> curve than a lead acid. >> Their peak current vs voltage generally is better than a lead acid. The BMS >> may impact this if it >> is an issue in your setup. They also is a *lot* lighter / smaller for the >> same amount of useful >> capacity. The built in BMS *should* take care of all of the fiddly little >> issues that might burn the >> house down. Lots to like other than the absolutely giant hole in the wallet >> …. >> Bob > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
