Lithium, Mixing Sinopoly LFP and Winston LFYP Cells??

[Barboots]

Glad I only bought one by the sound of it. Devising a way to control the current would be more effort than it's worth.

I'll test to see how it hangs in there before I install it. Thanks for the heads up.

Cheers,
Steve

[T1 Terry]

If over current is a problem then you could run the DC to DC through the Dingo solar input as the Dingo will current limit and this can be adjusted via the menu. The down side is the battery positive and negative cables running to the Dingo may need the be upgraded to handle the extra current if only the light gauge 13 core harness wires were used, but the positive signal core wire will now need to go to the B+ sensing wire on the right of the small green plug to the left of the Dingo terminal section.
The other method is a copper wire wound choke using a ferrite ring for the core..... adding in the possible 19v input to get a 14v output @ 20 amps will mean a bit of heat build up..... a variable frequency switch to an independent SSR for each DC to DC could also be used to limit the current via PWM control, but all this added circuitry reduces the value and viability of these units so....... even using multiple MPPT controllers brings up a level of difficulty because it requires quite a bit of rework to get them to work together in a master/slave configuration, something I'm yet to try myself but Julian has given me the required circuitry and equipment layout to see if I can get it to work for me.

T1 Terry

[Barboots]

If over current is a problem then you could run the DC to DC through the Dingo solar input as the Dingo will current limit and this can be adjusted via the menu. The down side is the battery positive and negative cables running to the Dingo may need the be upgraded to handle the extra current if only the light gauge 13 core harness wires were used, but the positive signal core wire will now need to go to the B+ sensing wire on the right of the small green plug to the left of the Dingo terminal section.
T1 Terry

That sounds like an easily implemented approach Terry. Thanks for the lead... I'll be in touch if I get stuck with the config. [emoji1]

Cheers,
Steve

[Barboots]

If over current is a problem then you could run the DC to DC through the Dingo solar input as the Dingo will current limit and this can be adjusted via the menu. The down side is the battery positive and negative cables running to the Dingo may need the be upgraded to handle the extra current if only the light gauge 13 core harness wires were used, but the positive signal core wire will now need to go to the B+ sensing wire on the right of the small green plug to the left of the Dingo terminal section.
T1 Terry

So my cheap DC-DC converter was unable to maintain 19V out when connected to the Dingo/SSR... the output dropped to the bank voltage and current fell to around 5A. I'm now rewiring the Dingo as per T1's above, which I should have done originally ask it provides a redundancy.

Terry could I confirm:
- the "positive signal core wire" is the one which drives the SSR? I simply move it across to the small green B+ terminal???

- do I need to make programming changes prior to doing anything? If so, could you educate me please?

I'll be running fused 6B&S between the Dingo and the Gigavac in the interim [emoji106]

Cheers,
Steve

[T1 Terry]

If over current is a problem then you could run the DC to DC through the Dingo solar input as the Dingo will current limit and this can be adjusted via the menu. The down side is the battery positive and negative cables running to the Dingo may need the be upgraded to handle the extra current if only the light gauge 13 core harness wires were used, but the positive signal core wire will now need to go to the B+ sensing wire on the right of the small green plug to the left of the Dingo terminal section.
T1 Terry

So my cheap DC-DC converter was unable to maintain 19V out when connected to the Dingo/SSR... the output dropped to the bank voltage and current fell to around 5A. I'm now rewiring the Dingo as per T1's above, which I should have done originally ask it provides a redundancy.

Terry could I confirm:
- the "positive signal core wire" is the one which drives the SSR? I simply move it across to the small green B+ terminal???

- do I need to make programming changes prior to doing anything? If so, could you educate me please?

I'll be running fused 6B&S between the Dingo and the Gigavac in the interim [emoji106]

Cheers,
Steve

Ummmm.... email me a photo of your Dingo wiring and I'll label it as to what goes where, then send it back, save confusion that way and someone trying to follow it but having different coloured wires and ....... you know the rest of how that one goes

T1 Terry

[Firegirl54]

Hi Steve, Terry,
As mentioned in my post above (July 30), I got the idea of using the dc/dc into the Victron mppt from some Morningstar tech notes. They specifically said it was a goer for their MPPT but not PWM controllers, but did not explain why.....Maybe what Steve is seeing is the reason? The mppt holds its incoming voltage at a level that optimises power transfer, so a steady 19v from the dc/dc to the controller. But the dumb dc converter, faced with minimal resistance into the lithiums via just a ssr lets its output voltage drop ....whether it will do the same through the dingo PWM circuitry will be interesting to see.
As an aside, I tried using the 12 to 19 dc converter to boost the voltage from a 32 cell panel (normally too low to work through the victron at all). It worked, but extremely inefficiently. Droppped its input voltage to 9V, boosted to 19 OK, but started to get warm, and only a few amps flowed to the battery. Got about three times as much just connecting the panel directly to the battery.*

[T1 Terry]

Thanks Leslie,
It appears the 19v output at 20 amps must be the result of some sort of circuitry to required the 19v to be maintained to produce the max current rather than the current being maintained at any voltage up to 19v. Just to confirm that idea, could you check the MPPT input voltage from this DC to DC device and confirm it remains at 19v please Leslie?

T1 Terry

[Firegirl54]

Hi Terry,
Yes, I had checked, and it does hold a steady 19V from the dc dc into the victron mppt. (See full details in post on p3 from August 28). Won't be able to check anything else for a while though....we are in Germany at the moment!
Cheers, Leslie

[Barboots]

I can confirm that the approach of using the Dingo as a current limiting system doesn't work. So I have three options:

- Double down on the current approach and buy a Victron 100/50, then see if it'll work in parallel with the Dingo/SSR solar. If it did, I'd buy another Choina DC-DC for a total of 40A. Actually, I'd probably buy the knock-off version of the 100/50 for $190. http://www.ebay.com.au/itm/282639572775

- Buy one of those expensive Redarc 40A DC-DC devices and see if it lives up to the hype, and also if it will work in parallel with the Dingo/SSR solar.

- Rewire the van as heavy as the car's 3B&S, and see if I can stiffen up the voltage reaching the lithium.

I might test the latter with a mocked up equivalent before proceeding. Discussion welcome.

[cruiserxxx]

Was reading thru the specs on my batteries and noticed this warning:
9.3.8 Do not use Lithium ion cell with the primary batteries or secondary batteries whose capacity or kinds
or maker is different. If do that, the cell will be discharged or charged excessively in use. And it may cause the
generating heat, smoke, rupture or flame because of the abnormal chemical reaction in cells.