It would be useful to know what the issues they had actually were?
There are two issues as far as I am concerned with Lithiums ...
1) All too often they are advertised as "drop in replacements" and people don't take the time to check the small (sometimes invisible) print where it says this is assuming the chargers installed are suitable and there is a way to monitor the batteries.
Many motorhomes have borderline charging systems that were designed to charge Lead Acid batteries and do not expect to be running at 100% for hours until a Lithium
battery (which will eat all it can until full) is fully charged.
It is like expecting to be able to run the engine at the red line constantly. Yes, you could, but you probably wouldn't as it will not be very good for the engine. Why would you run a charger at full pelt and expect no issues?
Fitting truely Lithium capable chargers where the designers expect a high load is another matter and decent ones are designed to handle the constant load.
LIthium needs a capable charging and monitoring support system to work correctly.
2) Cheap Lithiums, sometimes made from grade B cells (ones that have failed to pass the QC checks), fitted with BMSes made as cheaply as possible.
People buy Lithium Batteries expecting them to last much longer than Lead Acid Batteries, and they usually have an very attractive looking warranty period of 6, 7, or maybe 10 years. But what some of these companies supplying the "bargain" batteries don't publicise in the same way is the BMS may only be warranted for 12 months (KS Energy and Roamer I know about. There may well be others?). These cheap BMSes also tend to be fairly unreliable in electronic terms, so even if it is covered by warranty, your
battery could still be unusable while the fault exists and then still need to wait for it to be taken away, tested probably and then possibly repaired or more likely just replaced (ps. the Warranty terms will be the customer pays shipping, so it will still cost you).
Also mentioned was about Standby? BMSes by default have a setting to go into sleep mode when there is no load. The problem is "no load" does no equal 0A. It is possible for some of these batterie to enter standby/sleep when in use! Some folk have actually reported a fairly significant load (in Amps, not Milliamps) and it going to sleep.
For the Leisure industry I personally see no point in having this auto-sleep function. And the observation about one of the major
battery suppliers not supplying batteries with the sleep function is correct. This is Alpha Batteries. The Lithium
Battery range they get from their Far Eastern manufacturers they specify that feature to be disabled as standard.
What I would look for personally for Lithium is (and in no specific order):
- Track Record of supplying batteries.
- anyone can import Lithium Cells, BMSes, cases and become a Battery "Manufacturer", and good luck to them, but If I wanted to take a punt on that, I'd just build my own. It is not actually that hard to do. But to do it well is another matter.
- Designed to work in multiples.
- If the plan is to install multiple batteries connected together (common due to the way the battery spaces are in motorhomes), they ideally need a way to communicate with each other. Decent Batteries have cells that are 'matched', but too often, especially with cheaper batteries, different, nominally identical, batteries have different packs of cells from one to another which causes mismatches of discharge and recharge. One job of the BMS in a Lithium Battery is to balance the individual cells within a battery, but the better BMSes extend that function so they will talk battery to battery to balance complete batteries. This is not that common a feature sadly, but is a very useful one.
- Full Warranty with no component exclusions.
- I would discount any battery that had a limited warranty on a specific item such as a BMS. To me, that indicates a lack of faith in the product and questions their choice and ability to specify quality components. IMO, I think a Lithium Battery will probably fail due to the BMS anyway eventually for most people, and to have a question mark on that from the outset would not be acceptable.
- Servicability
- This is maybe a dubious thing to look for maybe? But being able to repair a battery is a desirable feature for maybe the owner later on when the BMS has failed after a few years, or for the supplier who could actually repair and return a failed battery economically. I think most people who are interested in Lithium Batteries will have watched Youtube videos of people doing "tear downs" of Lithiums, getting out their stanley knives, dremels, or reciprocating saws (incredible and stupid) ripping apart batteries. Why don't batteries have removable tops to allow service? There is no acid sloshing around that means there needs to be a chemically secure seal. In fact some do. (mine certainly do).
- BMS Ability
- Touched on some desirable features of the BMS, but the key one is the Discharge and the Charge Currents. They need to be high enough to work for you. The typical 100Ah Lithium has a 100A limit BMS. If you had a single 100Ah battery, you could not successfully run an inverter to power say a Coffee Machine, Microwave, or similar. This is often a reason why people go for multiples in series to get a higher current limit (2 x 100Ah batteries with 100A BMSes will give you a 200A limit). The is a trend for the bigger batteries to get fitted with higher rated BMSes, but it is not automatic and there are Lithium batteries out there with 40A or even 20A!
To be frank, I would question their ability and knowledge, considering there are many many examples of LIthium
Battery setups working very well, installed by DIYers, small conversion companies and major manufacturers.
How did we survive without having all this power? We did add some mod cons I seem to remember. Someone bought a plug in 12v cool box which replaced the welly bar which I loved. The welly bar was a big green welly full of little 250ml bottles of beer for the journey (driver excluded).
