Travel to Live

 

 

 

 

 

We switched to lithium (LiFePO4) on our narrowboat this winter as we needed to replace our five lead acids and were alerted by a fellow boater to two second hand Valence U-Charge U27-12XP 130Ah packs at the ideal time. They’re about £1400 each new and we got them for £350 each, with 60 cycles on them according to the internal BMS. They were originally in an electric delivery van project (with 20 other packs) but the firm went bust. I wired them in parallel.They balance themselves internally and show their status with an LED which normally flashes green every 20 seconds.

Our boat is gas-free (electric cooking, built-in diesel generator) and we have high power demands – we routinely use a 1200W kettle on our inverter. We are not typical users (which itself justifies the higher outlay).

For us, our packs have freed us from many of the headaches of lead acid leisure batteries which I summarise as:

– slow to charge which wastes diesel, yet:
– having to think about charging up to 100% frequently except with mid-summer solar
– sulphate when left discharged
– can’t deliver much current (without a big bank of them)
– self discharge over time
– less available capacity: should only be discharged to 50% of capacity to preserve life
– heavy

though they they’ve given us other challenges:

– Resting voltage doesn’t vary much as you drain them: you can’t really tell the state of charge (at least between about 10% which is too low for comfort and 80%) from the voltage unless they’re under heavy load – a battery monitor with Ah counter helps. We don’t worry too much as I’ve installed some protective circuits which stop them being completely flattened by disconnecting the loads and turning off the remote switch of the inverter if the voltage goes below about 11.5v
– should not be held at high voltage – a problem when charging off the alternator during long cruises, although lead acid float voltages around 13.6v are fine
– prefer to be left partly discharged
– ruined if charged (even a few amps of solar) when below 0 deg C so in the recent cold weather we ran our Webasto which warms up the engine bay before thinking about charging.

We think of our lithiums as fine china plates. They should last well (good for conservatively 3000 cycles – eight years if we flattened and charged them every day) unless the resting voltage of the pack drops below 10v. Then it’s game over, like dropping a plate. One bad flattening and that’s basically it. I’m going to add some protection from high voltage too, which will quickly kill our batteries as well. We accept that we’re part of our battery management system!

If you want to know anything specific about living practically with LiFePO4 I’m happy to answer questions here.

Our jaded Singaporean friends at dinner on Saturday had advised us to use the Number 2 bus as a sightseeing option, and to take it to the end of the route, Changi Village, near the airport. This was the site of the infamous Changi prison, controlled by the Japanese during the war and where many atrocities were committed. Changi itself is now home to a Singapore Air Force base and the international airport as well as Changi prison, which is a very large new and high-tech facility, but Singapore deliberated oversized it and it is currently only a quarter full. They are intending to move many prisoners here from other places around the island. prison. Changi is also the jumping-off point for a number of boat tours, but the Singaporean anti-enthusiasts had rather dampened my enthusiasm for visiting Palau Ubin, (the famous “granite island” and home to some villages not unlike those of the 60s, before the mass expansion of building on the island of Singapore).

We emerged after an hour of travel on an air-conditioned bus into the most oppressive heat, right opposite the hawker centre. Neither of us was hungry, so we wandered through before crossing the main road and checking out a parade of cafes and restaurants. Mum espied an older, British couple chatting to a Singaporean man outside a small, but smart looking restaurant. We discovered that “Charlie” owned and ran the bar and he gave us helpful tips as I sat and drank exorbitant (as we discovered) imported beer. he advised us to take the 29 bus to an MRT (metro) station nearby and take a train back into town. After a sizable lunch in the hawker centre, we waited for a 29, letting many 2’s go by, though they probably would have been as good. I stood and chatted with a lady called Janice a former nurse, originally from Saskatchewan, now of Edinburgh from where she is sent worldwide to lecture on nurse management. We finally made it to the MRT station complex and after a little exploration found the platforms and pushed down to Harbourfront – the gateway to… Sentosa!

I’m sitting outside a shack-like house, listening to animal noises from the bush, maintaining my phone (backups and upgrades), drinking homebrew (with proper printed labels), waiting for Rotary dinner. Mum is naturally appalled by the location, which is running damp (there’s a small creek eight feet from my chair as I type) but I think it’s really rather fun, and much nicer than our noisy near to Central Station, Sydney. It’s well-located but far from plush. Everything is so expensive, from accommodation to food.