Hi I've a xb 700li and modified sine wave to charge it with.

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marcharm
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Hi I've a xb 700li and modified sine wave to charge it with.

With a nice modified winewave inverter will the charger encounter any problems in changing the voltage to the charging voltage of the batteries.
If it is ok it seems to be a way to have more batteries on the bike, an inverter, the charger and to recharge the bike on the go. Seems to work.

marcharm
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Re: Hi I've a xb 700li and modified sine wave to charge it ...

the ego came out with an extended battery pack for their bike.
could an extra matching battery pack to the xb 700 li just be plugged in using the battery charge port on the bike to double the range of the 700li?
it would be nice to have a differnt style of battery box that would fit on the floorboard still leaving plenty of foot room with the connection just going to the charge port of the bike. The two battery packs could be charged separately and indepently.
Just a thought for the trips of greater distance such as across the city and back.
charge time would still be the same using two chargers. One for each battery pack.
Humm.Logistics.
Raul

chas_stevenson
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Re: Hi I've a xb 700li and modified sine wave to charge it ...

To start with, a Modified Sine Wave Inverter (MSWI) is a bad choice to use with a charger. Chargers using a transformer in the design will overheat. Chargers using the switcher design will work but will also heat up more than normal. More heat indicates a drop in efficiency or a loss of power.

The next problem is the amount of power loss inherent using this idea. Every time you change the voltage from one value to another, there will be some loss. So you convert the power from the battery voltage to 120 VAC to run the charger. Most MSWI are only about 80% efficient, power loss. Then you convert the 120 VAC to the battery voltage. Most chargers are only about 90% efficient. Now you have lost twice, not a good thing.

If you want to add more batteries just add them to the pack you already have. This would be much more efficient and increase your range without carrying the extra weight of the inverter and the charger. The added weight is another form of power loss which makes this idea a 3 time looser.

Grandpa Chas S.

antiscab
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Re: Hi I've a xb 700li and modified sine wave to charge it ...

The first stage of a switcher design charger (actually an SMPS) is a full wave rectifier bridge.

An SMPS works *more* efficiently off of square wave (and to a lesser degree) modified sine wave (actually modified square wave, which is marketing speak for still crappy but less crappy than square wave).

the reason a SMPS power supply work more efficiently on square wave is because the filter just after the bridge rectifer output doesnt have to do anything to keep the voltage stable, where as for sine wave and modified square wave, the filter needs to level the voltage across the entire wave.

but yes, battery -> inverter -> charger -> battery is still a bad idea.

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

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