rich fraser

  • Posts: 205
What size battery
« on: March 25, 2024, 03:37:03 pm »
Currently running two pumps and one electric reel, other is manual.  What size amp hour battery would you use? Mostly local domestic work so not a lot of travel to charge up while on the road. Was thinking 200ah but not sure it’s an overkill??

Ian Sheppard

  • Posts: 1217
Re: What size battery
« Reply #1 on: March 25, 2024, 05:14:12 pm »
In part the question is how often will the battery need to be bench charged. As a rough estimate running two pumps and a power reel will see a current draw of between 4 and 8 amps per hour. In general a leisure battery should not be discharged below 50% of its capacity. Based on a 200 AH battery this gives 100 amps of usable energy before the battery would need to be Bench ( mains charged) Or 12.5 to 25 hours continuous working. As a general rule of Thumb the battery would ned to be charged once every 4 days Or so.

A Brand new fully charged battery should probably be charged at least once a week. Intelligent variable chargers are a good way to go. Regular charging would help extend the life of the battery by keeping the Cells in good condition

Cheers
Ian



 
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rich fraser

  • Posts: 205
Re: What size battery
« Reply #2 on: March 25, 2024, 05:45:51 pm »
In part the question is how often will the battery need to be bench charged. As a rough estimate running two pumps and a power reel will see a current draw of between 4 and 8 amps per hour. In general a leisure battery should not be discharged below 50% of its capacity. Based on a 200 AH battery this gives 100 amps of usable energy before the battery would need to be Bench ( mains charged) Or 12.5 to 25 hours continuous working. As a general rule of Thumb the battery would ned to be charged once every 4 days Or so.

A Brand new fully charged battery should probably be charged at least once a week. Intelligent variable chargers are a good way to go. Regular charging would help extend the life of the battery by keeping the Cells in good condition

Cheers
Ian

Thanks Ian. In short, a 200ah battery would not be an overkill then?

Perfect Windows

  • Posts: 4102
Re: What size battery
« Reply #3 on: March 25, 2024, 09:25:32 pm »
Currently running two pumps and one electric reel, other is manual.  What size amp hour battery would you use? Mostly local domestic work so not a lot of travel to charge up while on the road. Was thinking 200ah but not sure it’s an overkill??

If you're thinking about a 200Ah leisure battery you might want to consider a 100Ah LiFePO4 battery.

Lithium can withstand a much greater percentage drain and should last far, far longer then lead acid, and you're heading towards that kind of price point anyway.

A battery to battery charger (if you don't already have one) will help to keep it charged.

There's a thread on the subject recently updated. Might be worth a read.

Vin

Spruce

  • Posts: 8361
Re: What size battery
« Reply #4 on: March 26, 2024, 09:07:54 am »
Over the past few weeks we have just used our 2 pumps. The diesel heater hasn't been switched on.
Our lithium battery is fully charged using our Sterling b2b charger set on 30 amps with working in our local area.
The diesel heater is what discharges the battery more than what the b2b puts back.

If the suppliers are correct, then lithium likes to be discharged down to around 40% before being recharged.

If  I increase my charging output to 60 amps I'm pretty sure that the lithium battery would fully recharged even when using the heater.
But a higher charge rate would reduce the batteries longevity. By how much? I don't know.

I have also found that a few degrees increase of the battery's temperature with Spring means a higher charge rate acceptance above 80% state of charge.
When the battery temp was at 3 or 4 degrees the charge rate above 80% was 8 amps. At 8 degrees it's 16 amps. We will see how this changes into summer.
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Perfect Windows

  • Posts: 4102
Re: What size battery
« Reply #5 on: March 26, 2024, 11:18:58 am »
The temperature comment is interesting and might explain something.

The Sterling, at zero C or below, uses all the incoming charge to heat the battery. At 5C it reduces the current to the heaters (freeing up current to recharge) but keeps heating the battery until it reaches 15C.  Your post gives me a possible explanation: I guess the overall speed of charge at a higher temp is expected to more than balance out the slower charging at lower temperatures.

Whether it'll help in our short drive, long drain usage through a cold day is something we'll find out  I guess.

Vin

Perfect Windows

  • Posts: 4102
Re: What size battery
« Reply #6 on: March 26, 2024, 11:23:45 am »
Here's the blurb: "The heater comes on provided the cells temperature is at 0DegC or lower AND there is 50W | 100W of available power. Once the temperature hits 5DegC, the charge circuit engages to allow for charging current to flow into the battery. The heating element shall remain on until the battery temperature hits 15DegC. Therefore, for a period of time, some charge current shall be going into warming your cells up further and some charge current shall be passing into the lithium battery. Once 15DegC is met, the heating element turns off and all charging current goes into the battery. This resets the temperature based activation. "

Spruce

  • Posts: 8361
Re: What size battery
« Reply #7 on: March 26, 2024, 01:59:32 pm »
Here's the blurb: "The heater comes on provided the cells temperature is at 0DegC or lower AND there is 50W | 100W of available power. Once the temperature hits 5DegC, the charge circuit engages to allow for charging current to flow into the battery. The heating element shall remain on until the battery temperature hits 15DegC. Therefore, for a period of time, some charge current shall be going into warming your cells up further and some charge current shall be passing into the lithium battery. Once 15DegC is met, the heating element turns off and all charging current goes into the battery. This resets the temperature based activation. "

I will investigate this further with Fogstar when we get home in 2 weeks time.
I don't know at what temperature their heating element switches off at.
There just seems to be so many different ideas out there regarding lithium and it's charging characteristics.

My Sterling unit is charging at 13.6v which is way below the recommended 14.2v. But the battery is still being charged at the full b2b charger's output amps. So I don't believe increasing the charging voltage is going to charge my battery any quicker.

Lithium does have a bad press at the moment which is a negative. Lithium phosphate is a safer battery type than lithium ion, but doesn't have the density and the power punch.

I was initially hesitant buying this battery, but it's growing on me.

Success is 1% inspiration, 98% perspiration and 2% attention to detail!

The older I get, the better I was ;)

Spruce

  • Posts: 8361
Re: What size battery
« Reply #8 on: March 27, 2024, 06:02:00 pm »
Fogstar heating elements are activated when the battery temperature is at 0 degrees and below.

Low Temperature Charging

The battery has detected that you are trying to charge whilst the temperature is around 0°C. This warning is normal, and it is used to trigger the heating pads in your battery. Incoming charge current will heat the pads first, and then the battery will allow charge through when it reaches 5°C.

Never had that warning yet this winter, although it hasn't been that cold.
Success is 1% inspiration, 98% perspiration and 2% attention to detail!

The older I get, the better I was ;)