Batteries - Lithium Iron Phosphate or Lead Acid Gel?

[Adrian Harris]

I've got two of these:

http://www.powerhousegolf.co.uk/acatalo ... tml#SID=92

in the BARV but haven't done enough running to determine the likely length of running they provide.

They include the chargers, so a pair would be £358 including VAT.

One disadvantage is that they're quite big, so a pair of them take up more room than a similar pair of AGM batteries.

Adrian.

[vincent hung shu yue]

I bought 30A 24V of LifePO4 at the following . It cost 180 pounds for whole set.
And it definitely can run longer .Here is the link Vpower.hk
Regards
Vincent

[Gerhard Michel]

Well, I use 8 LiFePO4-cells CALB 40 Ah in my King Tiger since a year, and I am very pleased.



Charging / balancing ist done by the charger (Unsi iCharger 1010) in about one hour (40 A charging current) and the voltage of each cell I can see on the display of my transmitter. I use telemetry in all my tanks showing the following values on the transmitters display:

1. Voltage of driving battery. This is the only battery in the tank; all other voltages (12 V, 5 V) are made by dc-dc-converters
2. Actual overall current (may be very astonishing in some cases!)
3. Consumed capacity since power on in actual driving period


In the transmitter (Graupner MC 32) acoustic warning messages are programmed for:

1. RC signal low
2. Transmitter voltage
3. receiver voltage
4. overheating receiver
5. wrong voltage value at each of the 8 LiFe cells
6. overheating esc
7. Overheating drive motor

In the case of one thinks our drive units can only consume rather low currents, here my measured results (BT King Tiger with steel tracks; whole power consumption).

Driving straightforward: 4 A to 7 A, slight curve: 15 to 20 A, hill 30 degrees: 22 A, tableturn: 55 - 60 A. Hereby the motors are overloaded by additional 100 %! Acid batteries have a significant higher internal resistance and therefore a lower voltage at high loads, which increases the current furthermore. Here the LiFes are better giving more voltage to the drive unit, which usee less current and remains cooler.

[Stephen White]

Gerhard, very interesting data, thanks for posting. It reinforces some of the obvious advantages of Lithium, iron, phosphate over lead acid.

I still think there is some sceptiscism about the economics, with the higher initial acquisition costs being a deterrent. But if you look at whole life costs, which are a better measure, there is little to choose between them. It's interesting to see on the Forum the reports of lead acid batteries beginning to fail and need replacing, which is consistent with their shorter lifespan.

Regards.

Stephen

[Christoffer Ahlfors]

Indeed!

Detailed success stories are always welcome for us who are saving up the money.

Thanks, Gerhard!

/Chris