Emrhys Barrell tests a dozen 12V lithium batteries (60-120Ah) with integral charge monitoring and the results are surprising
Sterling AMPS 60 & and AMPS 100
- RRP: £599 (AMPS 60) and £1,250 (AMPS 100)
- Contact: sterling-power.com
Sterling have been supplying battery chargers and inverters for many years and one of their largest markets is emergency vehicles, who use their inverters to power the increasing array of 240V equipment used today. Concerned about the poor performance of lead acid batteries when used at high currents and down to low DoD, they looked for alternatives. Along with the lithium AMPS range they also supply battery-to-battery chargers, enabling the vehicle’s alternator to rapidly re-charge the batteries.
The two units performed remarkably well in the 100A/60A discharge test, delivering 119Ah and 77Ah respectively, both 20% above their rated capacities. The 60 maintained this performance at 95A, but the 100 fell away at 150A, only delivering 55Ah. Sterling put this down to the BMS in the 100 cutting off early. The maximum current figures reflected the same fact, with the 60 delivering 120A for five minutes, but the 100 only delivering 160A. Internally they have four prismatic cells each; outside there’s a removable carry strap.
Super B Epsilon 90
The Super B was the most expensive unit on test, but also one of the best performers. Its nominal capacity is only 90Ah, but it maintained this at 25A, 100A and 150A discharge. It also delivered 190A for five minutes. This will be down to the fact that it has a multi-cylinder cell arrangement internally.
Externally it has two carrying handles that fold flush, and labels with its full specification, and safety precautions. When it arrived the voltage was cut back for transport, but you were supplied with an Allen key to open up a plastic panel that revealed a row of dip-switches that you pressed to re-set it for normal use.
A USB memory stick had the full owners manual on it, and an app allows you to monitor the battery from your phone via Bluetooth. Disconcertingly there is no colour-coding for the battery terminals, and you have to peer closely at the symbols embossed in the black plastic case.
The company is based in Holland, and does its own in-house testing for capacity and discharge, with external testing for compliance. The cells come from China.
Mastervolt is one of the largest companies on the world marine electric power market, with a wide range of chargers, inverters, and batteries. They have had large 24V lithium battery packs for some years now, fitted to many of the biggest sailing yachts and superyachts, but this is their first self-contained 12V unit. In fact, apart from different colours for the plastic handles, it looks very similar to the Super B Epsilon 90 (above).
Certainly the performance figures are almost identical, and all the same comments about the case and the BMS apply, including the lack of colour coding for the terminals. Mastervolt say the battery has 240 cylindrical cells in it, and it is built, assembled and tested in the Netherlands.
Both this and the Super B have an identical LED display on the top showing state of charge, and warning you of low voltage, and they both offer you an App to monitor the battery via Bluetooth.
The one Transporter unit presently available has a multi-cylinder internal make up, using the ubiquitous 18650 cells. Externally it differs from all the others on test in having copper lugs with nuts and bolts for connecting the positive and negative cables, as opposed to recessed thread stainless steel terminals. Transporter say this gives a better electrical connection and avoids straining the internal connection to the cells if you should overtighten the bolts, or if they should corrode after some years service in a salt-water environment.
It has a removable carrying strap. It performed well up to 100A, but if the current exceeded this, even by 1A, after 30 seconds the BMS shut-down, and would not reset until you applied a charge voltage. This is clearly a design decision intended to prevent damage to the battery in the event of repeated long-term overload, but it seems unnecessarily fierce to us.
Victron Smart 100
Victron are another major player in the world portable power market, including marine, off-grid, and back-up power supplies, with chargers, inverters, solar panel controllers and a wide range of batteries.
Up until now their lithium batteries have required a separate external BMS, and the Smart 100 is the same, but we are told new self-contained units are coming out shortly. Internally the cells are of the four large prismatic type, with active continuous balancing. The batteries are assembled in China or Eastern Europe, but the company carries out its own in-house testing.
Externally the unit suffered from no colour coding of the terminals, with just embossed symbols, and had no way of lifting it except a tiny ridge round the top of the box.
Performance was excellent, exceeding its rating at 25A, 100A, and 150A, and delivering 205A for five minutes, and it has a phone App for battery monitoring.
Relion RB100 and RB100HP
Relion are another US company, with an extensive range of Lithium batteries, 12V, 24V and 48V, all made in China, and new models coming out all the time. They work in all the off-grid markets, and have their own development division.
The two units we had for test vary only in their maximum current capabilities, and as we understand it are similar internally, with multi-cylinder construction, but different BMS settings. This was borne out in our tests, with both delivering close to their rated capacities at 25A and 100A, but the RB100 giving just 82Ah at 150A, compared to the RB100HP’s 102Ah.
Maximum currents showed the same difference, with 178A for the RB100 and 198A for the high power version.
The RB100 has a pair of folding plastic lifting handles, as opposed to the RB100HP which has a lifting strap.
3 Lion 3L-100
The 3 Lion is supplied by NDS from Italy, one of the largest European players in the off-grid market, with an extensive range of chargers, inverters, solar panels, controllers, and lithium batteries, catering for the RV and caravan market as well as for boats.
Because of this the battery comes complete with a multi-function control box, and display, which takes power from each source – engine alternator, solar panels and charger – balancing the need of the battery, and then distributes it to various outlets, with all functions being shown on an LCD display. This is all included in its price.
Externally the case was similar to several others in the test, suggesting many of them may well come from the same Chinese factory. Positive and negative terminals are colour coded. Internally it has 132 cylindrical cells.
Performance was above its rated figure at 25A, close at 100A, but only 82Ah at 150A. Maximum current was 190A for five minutes.
EZA 100 and EZA 130
French company EZA is another major player in the off-grid, RV market. The 100 has prismatic Chinese cells, but they are assembled in Europe, and have a sturdy metal case compared to the plastic of all the others. The terminals are close together, and you would need to be careful with your spanner when connecting them. The unit has an internal BMS, and an array of LEDs on the top indicating state of charge.
Performance is close to its rated figure at 25A and 100A, but as it does not recommend being discharged at more then 100A we stopped here.
The EZA130 is a very substantial and sophisticated unit, again designed for the RV market, and assembled in France in a metal case. It has two inlet sockets and two outlets, and is designed to be connected to inputs from the engine alternator, plus an array of solar panels and a mains battery charger.
The two outlets will supply normal 12V demands, plus an inverter. Inside it has an integral battery-to-battery charger, designed to be used with the latest vehicle smart alternators, and a solar controller. It has an automatic shut-off that disconnects the battery when not in use for long periods.
Performance was up to its ratings at 25A and 130A, but again this was the maximum it was supposed to be discharged at.
The Lifos is new onto the market, and while it was below our target 100Ah, we included it as it could be of interest to the smallest trailable boat, or as power for a small electric outboard. The company has larger models in the pipeline.
It has a neat folding plastic handle, and its terminals have clever brass tapered posts, which can be used for battery cables with clamp ends, or unscrewed for ring connectors. Internally it has four prismatic cells, and is made in China under licence to Lifos.
Performance was at or close to its rated figures at 25A and 65A, but above 70A it shut down, in line with its specification.