Hi Scotty,
Victorian batteries eh, a bit behind the times, technically don't you think ;) Of course you must mean Victron which is what I use and they are certainly not 18th century! I blog for them part time btw. Victron do a number of different types:
https://www.victronenergy.com/batteries
To be fair lead (be that flooded, AGM variants or gel with Peukert exponents around 1.25) does not behave like lithium (be they lithium iron phosphate (LiFePO 4) chemistry which I use with Peukert around 1.05). You only have to look at charge and discharge profiles to see that. For example see the first two graphs I did in this blog a few years back:
https://www.victronenergy.com/blog/2015/03/30/batteries-lithium-ion-vs-agm/
I'm not sure what your friend's application is, as a car battery/starter battery or in an electric car. Regardless it is my view that one picks the appropriate tech for ones wallet and application. As I conclude in my blog with lithium there is a capital risk and capital upfront cost to take into account but subject to loads, lithium in terms of cost per cycle can be cost effective against AGM for example.
In terms of charging I use 2 of Victron's 200 Ah, 12.8V Lithiums in series for my small auxiliary direct drive on my sailing yacht. Unlike lead acid tech which might have 4 charge stages of bulk, absorption, float and storage at say a recommended charge rate of 0.2C, I charge my lithiums at 14.2 V, or rather 28.4 as a series string, to around 90 to 95% which can be at a recommended rate of 0.5C. If I want to balance the cells (as balancing is built into the battery casing) I continue for about an hour. I also have a BMS and over/under voltage cut off relays. I can programme and start/stop my charger/s over the internet via the free Victron VRM (Victron Remote Management) site, as my boat has a 4G router and Victron Color Control GX.
When it comes to batteries for electric boats I'd personally be using either Victron's new Super Cycle AGM which has some interesting properties or a TPPL AGM type such as Odyssey or Northstar, if not going the lithium route.
If I were rich and my boat a bit bigger though, I'd probably choose something like a Deep Blue direct drive:
http://www.torqeedo.com/en/products/inboards
Why you may ask? Because they now use the BMW i3 battery with a 9 year warranty. Having said that batteries of all types do behave if treated properly to the manufacturers specs. I know I'm delighted with my lithiums which will probably outlast me!
If your friend needs more info or has queries he/she should speak to their Victron dealer.
John R
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