Pye_End
Well-Known Member
Does the DC to DC charger give the required charging profile for a Lithium? If so, can you not just keep an existing charger on the starter battery, and let the DC to DC do the rest, like it does with the alternator?
Lithium battery upgrade charging question
- Thread starter kevsbox
- Start date
Does the DC to DC charger give the required charging profile for a Lithium? If so, can you not just keep an existing charger on the starter battery, and let the DC to DC do the rest, like it does with the alternator?
geem
Well-Known Member
You need a charger to have a higher output than the DC/DC otherwise it will pulse on and off.
Three DC/DC has lithium profile and they are fully programmable
Pye_End
Well-Known Member
Ah. Is it because the engine battery loses charge to the lithium, and if it drops too far then the DC to DC cuts out till the voltage of the engine battery comes back up? So, lengthening the charge time? Any other drawbacks eg. quality of charge? If this is the reason, how far down will it take the engine battery - ie. how long then to recover, or does it go in and out in short order, and yo-yo's around? Could you instead bypass the DC to DC when on shorepower only, and just charge as a hybrid circuit?
PaulRainbow
Well-Known Member
That's what happens if the DC-DC charger can take more from the engine battery than the charger can put back in.
Depends on the output of the mains charger, the output of the DC-DC charger and the DC-DC charger settings.
Not the way to do it.
Have a high output mains charger to quickly charge the LFP.
You probably don't need a charger for the engine battery, unless you leave it for long periods without using the boat. If you do need one, it can just be a small charger or even a small solar panel. If the existing charger isn't suitable for LFP you can use it to charge the engine battery and buy a new charger for the LFP.
If charging the engine battery might trigger the DC-DC charger wire the remote connection on the DC-DC charger so that it only works if the engine battery is switched on or the engine is actually running.
kevsbox
Well-Known Member
Thanks for all the feedback, I think I have this now, please see below, any comments please.
So my shopping list looks like this
You will see I have listed 2 batteries here, 1 a lot cheaper then the other, anyone got any thoughts on these two please, is there a reason for the price difference?
Pardon our interruption...
Pardon our interruption...
So my shopping list looks like this
| ECO-WORTHY 12V 280Ah LiFePO4 Lithium Battery | Pardon our interruption... | £450 |
| Or | ||
| 12V 300Ah Lifepo4 Battery Lithium Leisure Battery | Pardon our interruption... | £280 |
| Victron SmartSolar MPPT Solar Charge 100/50 | https://www.amazon.co.uk/dp/B073ZJ43L1 | £130 |
| Victron DC/DC Charger 12/12 - 18 (Max 20A) | https://www.amazon.co.uk/dp/B0851TPKV7 | £130 |
| Victron Energy Smart Battery Shunt | https://www.amazon.co.uk/dp/B0DJ2P2XN5 | £060 |
| Victron Blue Smart Charger (Main) | https://www.amazon.co.uk/dp/B082X98M79 | £120 |
You will see I have listed 2 batteries here, 1 a lot cheaper then the other, anyone got any thoughts on these two please, is there a reason for the price difference?
Pardon our interruption...
Pardon our interruption...
geem
Well-Known Member
I definitely wouldn't touch the cheap lithium. I would look at the Fogstar range of batteries. More expensive but known cells and bms. UK company so warranty will count for something
kevsbox
Well-Known Member
Thanks, When I read Fogstar I could not help but think of Frogstar from The Hitchhikers guide
geem
Well-Known Member
Yep. Stupid name but good batteries. The bluetooth BMS function is essential
PaulRainbow
Well-Known Member
Definitely Fogstar.
Brc45
Active Member
I learned much from this webinar on solar from Pacific Yacht Systems in Canada: Solar episode
So, their online shop seems a good way to sort out what's recommended and just buy that locally.
So, their online shop seems a good way to sort out what's recommended and just buy that locally.
kevsbox
Well-Known Member
Thanks for all helpful feedback, I now think I have all but one thing sorted and understood as per diagram shown below.
My last question is in regard to our bilge pump, this is of course always on and at present is directly connected to the starter battery. We have never needed it and hopefully never will. My question is can these be connected directly to the lithium battery or should I leave as is?
So what I have now is
Starter system – Standard battery charged as follows
My last question is in regard to our bilge pump, this is of course always on and at present is directly connected to the starter battery. We have never needed it and hopefully never will. My question is can these be connected directly to the lithium battery or should I leave as is?
So what I have now is
Starter system – Standard battery charged as follows
- 1 x 30w Solar panel via existing charge controller
- Engine alternator (40A)
- Mains via Micro-Tec battery charger
- 2 x 50 W solar panels via MPPT 100/50 charge controller
- Mains via Blue Smart IP22 Charger 12/20 battery charger
- Engine alternator (40A) via Starter Battery and 12/12 DC/DC charger
- Fogstar Drift ECO 12V LiFePO4 Leisure Battery
- Victron SmartSolar MPPT Solar Charge 100/50
- Victron DC/DC Charger 12/12 - 18 (Max 20A)
- Victron Energy Smart Battery Shunt
- Victron Blue Smart Charger (Main)
jakew009
Well-Known Member
I would hook the bilge pumps up to your lithium battery. If your boat is sinking you want the pump to run for as long as possible
PaulRainbow
Well-Known Member
All good stuff, but i'd go for the Fogstar drift, rather than the ECO. A little more money, but well spent as they use better cells and better BMS with Bluetooth (Bluetooth is a must).
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noelex
Well-Known Member
You can safely use a much smaller (and therefore cheaper) controller. Even the smallest Victron 75/10 is big enough for two 50W panels.
vas
Well-Known Member
+1
I have 2X300W panels on a 100 | 30 and its less than 50% of it's capabilities
Unless of course you plan to throw these two tiny ones away and install 3-4 300+W ones
V.
toothless
Well-Known Member
A point on victron warranty - I had one of their orion tr dc dc converters actually catch fire on board when just powering a raspberry pi. I'll never understand how or why. The dealer said it was over three months so I needed to speak to victron. Victron were very interested in the fire but never answered my questions about a refund or replacement -they literally ignored those parts of each email despite answering other points and asking their own.
I never got a refund or a replacement. Shame as the boat is nearly all victron but I think I'll just drift to other solutions in the future.
I never got a refund or a replacement. Shame as the boat is nearly all victron but I think I'll just drift to other solutions in the future.
lustyd
Well-Known Member
At what battery voltage? Although Victron suggest under-speccing to save money, it does waste Watts that could have been captured.
600W at 12V is 50A so a 100/30 is not at 50% in that scenario, but 24V it would be fine (still not 50% though!).
lustyd
Well-Known Member
I'd expect more than that, are they shaded by antennas etc. at all? Even on a UK summer day you should get 100% rated output or slightly over that (we get 105% on our Renogy flexi panels). In Greece you should get that fairly consistently I'd have thought. Are the cables thick enough for the run length?
vas
Well-Known Member
yep, cables thick enough, and they are in series, so 85-90V coming down so no need for extra thick cables. I'm a bit worried myself tbh as it seems that performance has dropped over the last few years, panels are 10yrs old now (proper rigid ones). And yes, no shadows really when the sun is high up.
Thinking of redoing the f/b connectors they are meant to be properly sealed ones but who knows...
Other than that, probably replace the panels in a couple of years time.
V.
